[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/ext4/extents.c b/ap/os/linux/linux-3.4.x/fs/ext4/extents.c
new file mode 100644
index 0000000..bbe09a9
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/ext4/extents.c
@@ -0,0 +1,4954 @@
+/*
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * Architecture independence:
+ * Copyright (c) 2005, Bull S.A.
+ * Written by Pierre Peiffer <pierre.peiffer@bull.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
+ */
+
+/*
+ * Extents support for EXT4
+ *
+ * TODO:
+ * - ext4*_error() should be used in some situations
+ * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
+ * - smart tree reduction
+ */
+
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/jbd2.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/falloc.h>
+#include <asm/uaccess.h>
+#include <linux/fiemap.h>
+#include "ext4_jbd2.h"
+
+#include <trace/events/ext4.h>
+
+/*
+ * used by extent splitting.
+ */
+#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
+ due to ENOSPC */
+#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
+#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
+
+#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
+#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
+
+static int ext4_split_extent(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_map_blocks *map,
+ int split_flag,
+ int flags);
+
+static int ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t split,
+ int split_flag,
+ int flags);
+
+static int ext4_ext_truncate_extend_restart(handle_t *handle,
+ struct inode *inode,
+ int needed)
+{
+ int err;
+
+ if (!ext4_handle_valid(handle))
+ return 0;
+ if (handle->h_buffer_credits > needed)
+ return 0;
+ err = ext4_journal_extend(handle, needed);
+ if (err <= 0)
+ return err;
+ err = ext4_truncate_restart_trans(handle, inode, needed);
+ if (err == 0)
+ err = -EAGAIN;
+
+ return err;
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ */
+static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ if (path->p_bh) {
+ /* path points to block */
+ return ext4_journal_get_write_access(handle, path->p_bh);
+ }
+ /* path points to leaf/index in inode body */
+ /* we use in-core data, no need to protect them */
+ return 0;
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ * - EIO
+ */
+#define ext4_ext_dirty(handle, inode, path) \
+ __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
+static int __ext4_ext_dirty(const char *where, unsigned int line,
+ handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ int err;
+ if (path->p_bh) {
+ /* path points to block */
+ err = __ext4_handle_dirty_metadata(where, line, handle,
+ inode, path->p_bh);
+ } else {
+ /* path points to leaf/index in inode body */
+ err = ext4_mark_inode_dirty(handle, inode);
+ }
+ return err;
+}
+
+static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t block)
+{
+ if (path) {
+ int depth = path->p_depth;
+ struct ext4_extent *ex;
+
+ /*
+ * Try to predict block placement assuming that we are
+ * filling in a file which will eventually be
+ * non-sparse --- i.e., in the case of libbfd writing
+ * an ELF object sections out-of-order but in a way
+ * the eventually results in a contiguous object or
+ * executable file, or some database extending a table
+ * space file. However, this is actually somewhat
+ * non-ideal if we are writing a sparse file such as
+ * qemu or KVM writing a raw image file that is going
+ * to stay fairly sparse, since it will end up
+ * fragmenting the file system's free space. Maybe we
+ * should have some hueristics or some way to allow
+ * userspace to pass a hint to file system,
+ * especially if the latter case turns out to be
+ * common.
+ */
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
+ ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
+
+ if (block > ext_block)
+ return ext_pblk + (block - ext_block);
+ else
+ return ext_pblk - (ext_block - block);
+ }
+
+ /* it looks like index is empty;
+ * try to find starting block from index itself */
+ if (path[depth].p_bh)
+ return path[depth].p_bh->b_blocknr;
+ }
+
+ /* OK. use inode's group */
+ return ext4_inode_to_goal_block(inode);
+}
+
+/*
+ * Allocation for a meta data block
+ */
+static ext4_fsblk_t
+ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex, int *err, unsigned int flags)
+{
+ ext4_fsblk_t goal, newblock;
+
+ goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
+ newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+ NULL, err);
+ return newblock;
+}
+
+static inline int ext4_ext_space_block(struct inode *inode, int check)
+{
+ int size;
+
+ size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 6)
+ size = 6;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
+{
+ int size;
+
+ size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent_idx);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 5)
+ size = 5;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_root(struct inode *inode, int check)
+{
+ int size;
+
+ size = sizeof(EXT4_I(inode)->i_data);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 3)
+ size = 3;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
+{
+ int size;
+
+ size = sizeof(EXT4_I(inode)->i_data);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent_idx);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 4)
+ size = 4;
+#endif
+ return size;
+}
+
+/*
+ * Calculate the number of metadata blocks needed
+ * to allocate @blocks
+ * Worse case is one block per extent
+ */
+int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int idxs;
+
+ idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent_idx));
+
+ /*
+ * If the new delayed allocation block is contiguous with the
+ * previous da block, it can share index blocks with the
+ * previous block, so we only need to allocate a new index
+ * block every idxs leaf blocks. At ldxs**2 blocks, we need
+ * an additional index block, and at ldxs**3 blocks, yet
+ * another index blocks.
+ */
+ if (ei->i_da_metadata_calc_len &&
+ ei->i_da_metadata_calc_last_lblock+1 == lblock) {
+ int num = 0;
+
+ if ((ei->i_da_metadata_calc_len % idxs) == 0)
+ num++;
+ if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
+ num++;
+ if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
+ num++;
+ ei->i_da_metadata_calc_len = 0;
+ } else
+ ei->i_da_metadata_calc_len++;
+ ei->i_da_metadata_calc_last_lblock++;
+ return num;
+ }
+
+ /*
+ * In the worst case we need a new set of index blocks at
+ * every level of the inode's extent tree.
+ */
+ ei->i_da_metadata_calc_len = 1;
+ ei->i_da_metadata_calc_last_lblock = lblock;
+ return ext_depth(inode) + 1;
+}
+
+static int
+ext4_ext_max_entries(struct inode *inode, int depth)
+{
+ int max;
+
+ if (depth == ext_depth(inode)) {
+ if (depth == 0)
+ max = ext4_ext_space_root(inode, 1);
+ else
+ max = ext4_ext_space_root_idx(inode, 1);
+ } else {
+ if (depth == 0)
+ max = ext4_ext_space_block(inode, 1);
+ else
+ max = ext4_ext_space_block_idx(inode, 1);
+ }
+
+ return max;
+}
+
+static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
+{
+ ext4_fsblk_t block = ext4_ext_pblock(ext);
+ int len = ext4_ext_get_actual_len(ext);
+ ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
+ ext4_lblk_t last = lblock + len - 1;
+
+ if (len == 0 || lblock > last)
+ return 0;
+ return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
+}
+
+static int ext4_valid_extent_idx(struct inode *inode,
+ struct ext4_extent_idx *ext_idx)
+{
+ ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
+
+ return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
+}
+
+static int ext4_valid_extent_entries(struct inode *inode,
+ struct ext4_extent_header *eh,
+ int depth)
+{
+ unsigned short entries;
+ if (eh->eh_entries == 0)
+ return 1;
+
+ entries = le16_to_cpu(eh->eh_entries);
+
+ if (depth == 0) {
+ /* leaf entries */
+ struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
+ struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
+ ext4_fsblk_t pblock = 0;
+ ext4_lblk_t lblock = 0;
+ ext4_lblk_t prev = 0;
+ int len = 0;
+ while (entries) {
+ if (!ext4_valid_extent(inode, ext))
+ return 0;
+
+ /* Check for overlapping extents */
+ lblock = le32_to_cpu(ext->ee_block);
+ len = ext4_ext_get_actual_len(ext);
+ if ((lblock <= prev) && prev) {
+ pblock = ext4_ext_pblock(ext);
+ es->s_last_error_block = cpu_to_le64(pblock);
+ return 0;
+ }
+ ext++;
+ entries--;
+ prev = lblock + len - 1;
+ }
+ } else {
+ struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
+ while (entries) {
+ if (!ext4_valid_extent_idx(inode, ext_idx))
+ return 0;
+ ext_idx++;
+ entries--;
+ }
+ }
+ return 1;
+}
+
+static int __ext4_ext_check(const char *function, unsigned int line,
+ struct inode *inode, struct ext4_extent_header *eh,
+ int depth)
+{
+ const char *error_msg;
+ int max = 0;
+
+ if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
+ error_msg = "invalid magic";
+ goto corrupted;
+ }
+ if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
+ error_msg = "unexpected eh_depth";
+ goto corrupted;
+ }
+ if (unlikely(eh->eh_max == 0)) {
+ error_msg = "invalid eh_max";
+ goto corrupted;
+ }
+ max = ext4_ext_max_entries(inode, depth);
+ if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
+ error_msg = "too large eh_max";
+ goto corrupted;
+ }
+ if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
+ error_msg = "invalid eh_entries";
+ goto corrupted;
+ }
+ if (!ext4_valid_extent_entries(inode, eh, depth)) {
+ error_msg = "invalid extent entries";
+ goto corrupted;
+ }
+ return 0;
+
+corrupted:
+ ext4_error_inode(inode, function, line, 0,
+ "bad header/extent: %s - magic %x, "
+ "entries %u, max %u(%u), depth %u(%u)",
+ error_msg, le16_to_cpu(eh->eh_magic),
+ le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
+ max, le16_to_cpu(eh->eh_depth), depth);
+
+ return -EIO;
+}
+
+#define ext4_ext_check(inode, eh, depth) \
+ __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
+
+int ext4_ext_check_inode(struct inode *inode)
+{
+ return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
+}
+
+#ifdef EXT_DEBUG
+static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
+{
+ int k, l = path->p_depth;
+
+ ext_debug("path:");
+ for (k = 0; k <= l; k++, path++) {
+ if (path->p_idx) {
+ ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
+ ext4_idx_pblock(path->p_idx));
+ } else if (path->p_ext) {
+ ext_debug(" %d:[%d]%d:%llu ",
+ le32_to_cpu(path->p_ext->ee_block),
+ ext4_ext_is_uninitialized(path->p_ext),
+ ext4_ext_get_actual_len(path->p_ext),
+ ext4_ext_pblock(path->p_ext));
+ } else
+ ext_debug(" []");
+ }
+ ext_debug("\n");
+}
+
+static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent_header *eh;
+ struct ext4_extent *ex;
+ int i;
+
+ if (!path)
+ return;
+
+ eh = path[depth].p_hdr;
+ ex = EXT_FIRST_EXTENT(eh);
+
+ ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
+
+ for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
+ ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
+ ext4_ext_is_uninitialized(ex),
+ ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
+ }
+ ext_debug("\n");
+}
+
+static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
+ ext4_fsblk_t newblock, int level)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+
+ if (depth != level) {
+ struct ext4_extent_idx *idx;
+ idx = path[level].p_idx;
+ while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
+ ext_debug("%d: move %d:%llu in new index %llu\n", level,
+ le32_to_cpu(idx->ei_block),
+ ext4_idx_pblock(idx),
+ newblock);
+ idx++;
+ }
+
+ return;
+ }
+
+ ex = path[depth].p_ext;
+ while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
+ ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_pblock(ex),
+ ext4_ext_is_uninitialized(ex),
+ ext4_ext_get_actual_len(ex),
+ newblock);
+ ex++;
+ }
+}
+
+#else
+#define ext4_ext_show_path(inode, path)
+#define ext4_ext_show_leaf(inode, path)
+#define ext4_ext_show_move(inode, path, newblock, level)
+#endif
+
+void ext4_ext_drop_refs(struct ext4_ext_path *path)
+{
+ int depth = path->p_depth;
+ int i;
+
+ for (i = 0; i <= depth; i++, path++)
+ if (path->p_bh) {
+ brelse(path->p_bh);
+ path->p_bh = NULL;
+ }
+}
+
+/*
+ * ext4_ext_binsearch_idx:
+ * binary search for the closest index of the given block
+ * the header must be checked before calling this
+ */
+static void
+ext4_ext_binsearch_idx(struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t block)
+{
+ struct ext4_extent_header *eh = path->p_hdr;
+ struct ext4_extent_idx *r, *l, *m;
+
+
+ ext_debug("binsearch for %u(idx): ", block);
+
+ l = EXT_FIRST_INDEX(eh) + 1;
+ r = EXT_LAST_INDEX(eh);
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ if (block < le32_to_cpu(m->ei_block))
+ r = m - 1;
+ else
+ l = m + 1;
+ ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
+ m, le32_to_cpu(m->ei_block),
+ r, le32_to_cpu(r->ei_block));
+ }
+
+ path->p_idx = l - 1;
+ ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
+ ext4_idx_pblock(path->p_idx));
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext4_extent_idx *chix, *ix;
+ int k;
+
+ chix = ix = EXT_FIRST_INDEX(eh);
+ for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
+ if (k != 0 &&
+ le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
+ printk(KERN_DEBUG "k=%d, ix=0x%p, "
+ "first=0x%p\n", k,
+ ix, EXT_FIRST_INDEX(eh));
+ printk(KERN_DEBUG "%u <= %u\n",
+ le32_to_cpu(ix->ei_block),
+ le32_to_cpu(ix[-1].ei_block));
+ }
+ BUG_ON(k && le32_to_cpu(ix->ei_block)
+ <= le32_to_cpu(ix[-1].ei_block));
+ if (block < le32_to_cpu(ix->ei_block))
+ break;
+ chix = ix;
+ }
+ BUG_ON(chix != path->p_idx);
+ }
+#endif
+
+}
+
+/*
+ * ext4_ext_binsearch:
+ * binary search for closest extent of the given block
+ * the header must be checked before calling this
+ */
+static void
+ext4_ext_binsearch(struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t block)
+{
+ struct ext4_extent_header *eh = path->p_hdr;
+ struct ext4_extent *r, *l, *m;
+
+ if (eh->eh_entries == 0) {
+ /*
+ * this leaf is empty:
+ * we get such a leaf in split/add case
+ */
+ return;
+ }
+
+ ext_debug("binsearch for %u: ", block);
+
+ l = EXT_FIRST_EXTENT(eh) + 1;
+ r = EXT_LAST_EXTENT(eh);
+
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ if (block < le32_to_cpu(m->ee_block))
+ r = m - 1;
+ else
+ l = m + 1;
+ ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
+ m, le32_to_cpu(m->ee_block),
+ r, le32_to_cpu(r->ee_block));
+ }
+
+ path->p_ext = l - 1;
+ ext_debug(" -> %d:%llu:[%d]%d ",
+ le32_to_cpu(path->p_ext->ee_block),
+ ext4_ext_pblock(path->p_ext),
+ ext4_ext_is_uninitialized(path->p_ext),
+ ext4_ext_get_actual_len(path->p_ext));
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext4_extent *chex, *ex;
+ int k;
+
+ chex = ex = EXT_FIRST_EXTENT(eh);
+ for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
+ BUG_ON(k && le32_to_cpu(ex->ee_block)
+ <= le32_to_cpu(ex[-1].ee_block));
+ if (block < le32_to_cpu(ex->ee_block))
+ break;
+ chex = ex;
+ }
+ BUG_ON(chex != path->p_ext);
+ }
+#endif
+
+}
+
+int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
+{
+ struct ext4_extent_header *eh;
+
+ eh = ext_inode_hdr(inode);
+ eh->eh_depth = 0;
+ eh->eh_entries = 0;
+ eh->eh_magic = EXT4_EXT_MAGIC;
+ eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_ext_invalidate_cache(inode);
+ return 0;
+}
+
+struct ext4_ext_path *
+ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent_header *eh;
+ struct buffer_head *bh;
+ short int depth, i, ppos = 0, alloc = 0;
+ int ret;
+
+ eh = ext_inode_hdr(inode);
+ depth = ext_depth(inode);
+
+ /* account possible depth increase */
+ if (!path) {
+ path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
+ GFP_NOFS);
+ if (!path)
+ return ERR_PTR(-ENOMEM);
+ alloc = 1;
+ }
+ path[0].p_hdr = eh;
+ path[0].p_bh = NULL;
+
+ i = depth;
+ /* walk through the tree */
+ while (i) {
+ int need_to_validate = 0;
+
+ ext_debug("depth %d: num %d, max %d\n",
+ ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+
+ ext4_ext_binsearch_idx(inode, path + ppos, block);
+ path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+
+ bh = sb_getblk(inode->i_sb, path[ppos].p_block);
+ if (unlikely(!bh)) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ if (!bh_uptodate_or_lock(bh)) {
+ trace_ext4_ext_load_extent(inode, block,
+ path[ppos].p_block);
+ ret = bh_submit_read(bh);
+ if (ret < 0) {
+ put_bh(bh);
+ goto err;
+ }
+ /* validate the extent entries */
+ need_to_validate = 1;
+ }
+ eh = ext_block_hdr(bh);
+ ppos++;
+ if (unlikely(ppos > depth)) {
+ put_bh(bh);
+ EXT4_ERROR_INODE(inode,
+ "ppos %d > depth %d", ppos, depth);
+ ret = -EIO;
+ goto err;
+ }
+ path[ppos].p_bh = bh;
+ path[ppos].p_hdr = eh;
+ i--;
+
+ ret = need_to_validate ? ext4_ext_check(inode, eh, i) : 0;
+ if (ret < 0)
+ goto err;
+ }
+
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+ path[ppos].p_idx = NULL;
+
+ /* find extent */
+ ext4_ext_binsearch(inode, path + ppos, block);
+ /* if not an empty leaf */
+ if (path[ppos].p_ext)
+ path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
+
+ ext4_ext_show_path(inode, path);
+
+ return path;
+
+err:
+ ext4_ext_drop_refs(path);
+ if (alloc)
+ kfree(path);
+ return ERR_PTR(ret);
+}
+
+/*
+ * ext4_ext_insert_index:
+ * insert new index [@logical;@ptr] into the block at @curp;
+ * check where to insert: before @curp or after @curp
+ */
+static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *curp,
+ int logical, ext4_fsblk_t ptr)
+{
+ struct ext4_extent_idx *ix;
+ int len, err;
+
+ err = ext4_ext_get_access(handle, inode, curp);
+ if (err)
+ return err;
+
+ if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d == ei_block %d!",
+ logical, le32_to_cpu(curp->p_idx->ei_block));
+ return -EIO;
+ }
+
+ if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
+ >= le16_to_cpu(curp->p_hdr->eh_max))) {
+ EXT4_ERROR_INODE(inode,
+ "eh_entries %d >= eh_max %d!",
+ le16_to_cpu(curp->p_hdr->eh_entries),
+ le16_to_cpu(curp->p_hdr->eh_max));
+ return -EIO;
+ }
+
+ if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
+ /* insert after */
+ ext_debug("insert new index %d after: %llu\n", logical, ptr);
+ ix = curp->p_idx + 1;
+ } else {
+ /* insert before */
+ ext_debug("insert new index %d before: %llu\n", logical, ptr);
+ ix = curp->p_idx;
+ }
+
+ len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
+ BUG_ON(len < 0);
+ if (len > 0) {
+ ext_debug("insert new index %d: "
+ "move %d indices from 0x%p to 0x%p\n",
+ logical, len, ix, ix + 1);
+ memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
+ }
+
+ if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+ EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+ return -EIO;
+ }
+
+ ix->ei_block = cpu_to_le32(logical);
+ ext4_idx_store_pblock(ix, ptr);
+ le16_add_cpu(&curp->p_hdr->eh_entries, 1);
+
+ if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
+ EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
+ return -EIO;
+ }
+
+ err = ext4_ext_dirty(handle, inode, curp);
+ ext4_std_error(inode->i_sb, err);
+
+ return err;
+}
+
+/*
+ * ext4_ext_split:
+ * inserts new subtree into the path, using free index entry
+ * at depth @at:
+ * - allocates all needed blocks (new leaf and all intermediate index blocks)
+ * - makes decision where to split
+ * - moves remaining extents and index entries (right to the split point)
+ * into the newly allocated blocks
+ * - initializes subtree
+ */
+static int ext4_ext_split(handle_t *handle, struct inode *inode,
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext, int at)
+{
+ struct buffer_head *bh = NULL;
+ int depth = ext_depth(inode);
+ struct ext4_extent_header *neh;
+ struct ext4_extent_idx *fidx;
+ int i = at, k, m, a;
+ ext4_fsblk_t newblock, oldblock;
+ __le32 border;
+ ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
+ int err = 0;
+
+ /* make decision: where to split? */
+ /* FIXME: now decision is simplest: at current extent */
+
+ /* if current leaf will be split, then we should use
+ * border from split point */
+ if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
+ return -EIO;
+ }
+ if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
+ border = path[depth].p_ext[1].ee_block;
+ ext_debug("leaf will be split."
+ " next leaf starts at %d\n",
+ le32_to_cpu(border));
+ } else {
+ border = newext->ee_block;
+ ext_debug("leaf will be added."
+ " next leaf starts at %d\n",
+ le32_to_cpu(border));
+ }
+
+ /*
+ * If error occurs, then we break processing
+ * and mark filesystem read-only. index won't
+ * be inserted and tree will be in consistent
+ * state. Next mount will repair buffers too.
+ */
+
+ /*
+ * Get array to track all allocated blocks.
+ * We need this to handle errors and free blocks
+ * upon them.
+ */
+ ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
+ if (!ablocks)
+ return -ENOMEM;
+
+ /* allocate all needed blocks */
+ ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
+ for (a = 0; a < depth - at; a++) {
+ newblock = ext4_ext_new_meta_block(handle, inode, path,
+ newext, &err, flags);
+ if (newblock == 0)
+ goto cleanup;
+ ablocks[a] = newblock;
+ }
+
+ /* initialize new leaf */
+ newblock = ablocks[--a];
+ if (unlikely(newblock == 0)) {
+ EXT4_ERROR_INODE(inode, "newblock == 0!");
+ err = -EIO;
+ goto cleanup;
+ }
+ bh = sb_getblk(inode->i_sb, newblock);
+ if (!bh) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, bh);
+ if (err)
+ goto cleanup;
+
+ neh = ext_block_hdr(bh);
+ neh->eh_entries = 0;
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ neh->eh_depth = 0;
+
+ /* move remainder of path[depth] to the new leaf */
+ if (unlikely(path[depth].p_hdr->eh_entries !=
+ path[depth].p_hdr->eh_max)) {
+ EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
+ path[depth].p_hdr->eh_entries,
+ path[depth].p_hdr->eh_max);
+ err = -EIO;
+ goto cleanup;
+ }
+ /* start copy from next extent */
+ m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
+ ext4_ext_show_move(inode, path, newblock, depth);
+ if (m) {
+ struct ext4_extent *ex;
+ ex = EXT_FIRST_EXTENT(neh);
+ memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
+ le16_add_cpu(&neh->eh_entries, m);
+ }
+
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto cleanup;
+ brelse(bh);
+ bh = NULL;
+
+ /* correct old leaf */
+ if (m) {
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+ le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+
+ }
+
+ /* create intermediate indexes */
+ k = depth - at - 1;
+ if (unlikely(k < 0)) {
+ EXT4_ERROR_INODE(inode, "k %d < 0!", k);
+ err = -EIO;
+ goto cleanup;
+ }
+ if (k)
+ ext_debug("create %d intermediate indices\n", k);
+ /* insert new index into current index block */
+ /* current depth stored in i var */
+ i = depth - 1;
+ while (k--) {
+ oldblock = newblock;
+ newblock = ablocks[--a];
+ bh = sb_getblk(inode->i_sb, newblock);
+ if (!bh) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, bh);
+ if (err)
+ goto cleanup;
+
+ neh = ext_block_hdr(bh);
+ neh->eh_entries = cpu_to_le16(1);
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
+ neh->eh_depth = cpu_to_le16(depth - i);
+ fidx = EXT_FIRST_INDEX(neh);
+ fidx->ei_block = border;
+ ext4_idx_store_pblock(fidx, oldblock);
+
+ ext_debug("int.index at %d (block %llu): %u -> %llu\n",
+ i, newblock, le32_to_cpu(border), oldblock);
+
+ /* move remainder of path[i] to the new index block */
+ if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
+ EXT_LAST_INDEX(path[i].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
+ le32_to_cpu(path[i].p_ext->ee_block));
+ err = -EIO;
+ goto cleanup;
+ }
+ /* start copy indexes */
+ m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
+ ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
+ EXT_MAX_INDEX(path[i].p_hdr));
+ ext4_ext_show_move(inode, path, newblock, i);
+ if (m) {
+ memmove(++fidx, path[i].p_idx,
+ sizeof(struct ext4_extent_idx) * m);
+ le16_add_cpu(&neh->eh_entries, m);
+ }
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto cleanup;
+ brelse(bh);
+ bh = NULL;
+
+ /* correct old index */
+ if (m) {
+ err = ext4_ext_get_access(handle, inode, path + i);
+ if (err)
+ goto cleanup;
+ le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
+ err = ext4_ext_dirty(handle, inode, path + i);
+ if (err)
+ goto cleanup;
+ }
+
+ i--;
+ }
+
+ /* insert new index */
+ err = ext4_ext_insert_index(handle, inode, path + at,
+ le32_to_cpu(border), newblock);
+
+cleanup:
+ if (bh) {
+ if (buffer_locked(bh))
+ unlock_buffer(bh);
+ brelse(bh);
+ }
+
+ if (err) {
+ /* free all allocated blocks in error case */
+ for (i = 0; i < depth; i++) {
+ if (!ablocks[i])
+ continue;
+ ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
+ EXT4_FREE_BLOCKS_METADATA);
+ }
+ }
+ kfree(ablocks);
+
+ return err;
+}
+
+/*
+ * ext4_ext_grow_indepth:
+ * implements tree growing procedure:
+ * - allocates new block
+ * - moves top-level data (index block or leaf) into the new block
+ * - initializes new top-level, creating index that points to the
+ * just created block
+ */
+static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
+ unsigned int flags,
+ struct ext4_extent *newext)
+{
+ struct ext4_extent_header *neh;
+ struct buffer_head *bh;
+ ext4_fsblk_t newblock;
+ int err = 0;
+
+ newblock = ext4_ext_new_meta_block(handle, inode, NULL,
+ newext, &err, flags);
+ if (newblock == 0)
+ return err;
+
+ bh = sb_getblk(inode->i_sb, newblock);
+ if (!bh)
+ return -ENOMEM;
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, bh);
+ if (err) {
+ unlock_buffer(bh);
+ goto out;
+ }
+
+ /* move top-level index/leaf into new block */
+ memmove(bh->b_data, EXT4_I(inode)->i_data,
+ sizeof(EXT4_I(inode)->i_data));
+
+ /* set size of new block */
+ neh = ext_block_hdr(bh);
+ /* old root could have indexes or leaves
+ * so calculate e_max right way */
+ if (ext_depth(inode))
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
+ else
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto out;
+
+ /* Update top-level index: num,max,pointer */
+ neh = ext_inode_hdr(inode);
+ neh->eh_entries = cpu_to_le16(1);
+ ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
+ if (neh->eh_depth == 0) {
+ /* Root extent block becomes index block */
+ neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
+ EXT_FIRST_INDEX(neh)->ei_block =
+ EXT_FIRST_EXTENT(neh)->ee_block;
+ }
+ ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
+ le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
+ le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
+ ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
+
+ neh->eh_depth = cpu_to_le16(le16_to_cpu(neh->eh_depth) + 1);
+ ext4_mark_inode_dirty(handle, inode);
+out:
+ brelse(bh);
+
+ return err;
+}
+
+/*
+ * ext4_ext_create_new_leaf:
+ * finds empty index and adds new leaf.
+ * if no free index is found, then it requests in-depth growing.
+ */
+static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext)
+{
+ struct ext4_ext_path *curp;
+ int depth, i, err = 0;
+
+repeat:
+ i = depth = ext_depth(inode);
+
+ /* walk up to the tree and look for free index entry */
+ curp = path + depth;
+ while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
+ i--;
+ curp--;
+ }
+
+ /* we use already allocated block for index block,
+ * so subsequent data blocks should be contiguous */
+ if (EXT_HAS_FREE_INDEX(curp)) {
+ /* if we found index with free entry, then use that
+ * entry: create all needed subtree and add new leaf */
+ err = ext4_ext_split(handle, inode, flags, path, newext, i);
+ if (err)
+ goto out;
+
+ /* refill path */
+ ext4_ext_drop_refs(path);
+ path = ext4_ext_find_extent(inode,
+ (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+ path);
+ if (IS_ERR(path))
+ err = PTR_ERR(path);
+ } else {
+ /* tree is full, time to grow in depth */
+ err = ext4_ext_grow_indepth(handle, inode, flags, newext);
+ if (err)
+ goto out;
+
+ /* refill path */
+ ext4_ext_drop_refs(path);
+ path = ext4_ext_find_extent(inode,
+ (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+ path);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
+ }
+
+ /*
+ * only first (depth 0 -> 1) produces free space;
+ * in all other cases we have to split the grown tree
+ */
+ depth = ext_depth(inode);
+ if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
+ /* now we need to split */
+ goto repeat;
+ }
+ }
+
+out:
+ return err;
+}
+
+/*
+ * search the closest allocated block to the left for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+static int ext4_ext_search_left(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+ struct ext4_extent_idx *ix;
+ struct ext4_extent *ex;
+ int depth, ee_len;
+
+ if (unlikely(path == NULL)) {
+ EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
+ return -EIO;
+ }
+ depth = path->p_depth;
+ *phys = 0;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return 0;
+
+ /* usually extent in the path covers blocks smaller
+ * then *logical, but it can be that extent is the
+ * first one in the file */
+
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ if (*logical < le32_to_cpu(ex->ee_block)) {
+ if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
+ EXT4_ERROR_INODE(inode,
+ "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
+ *logical, le32_to_cpu(ex->ee_block));
+ return -EIO;
+ }
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
+ ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
+ EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
+ le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
+ depth);
+ return -EIO;
+ }
+ }
+ return 0;
+ }
+
+ if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d < ee_block %d + ee_len %d!",
+ *logical, le32_to_cpu(ex->ee_block), ee_len);
+ return -EIO;
+ }
+
+ *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
+ *phys = ext4_ext_pblock(ex) + ee_len - 1;
+ return 0;
+}
+
+/*
+ * search the closest allocated block to the right for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the largest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+static int ext4_ext_search_right(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *logical, ext4_fsblk_t *phys,
+ struct ext4_extent **ret_ex)
+{
+ struct buffer_head *bh = NULL;
+ struct ext4_extent_header *eh;
+ struct ext4_extent_idx *ix;
+ struct ext4_extent *ex;
+ ext4_fsblk_t block;
+ int depth; /* Note, NOT eh_depth; depth from top of tree */
+ int ee_len;
+
+ if (unlikely(path == NULL)) {
+ EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
+ return -EIO;
+ }
+ depth = path->p_depth;
+ *phys = 0;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return 0;
+
+ /* usually extent in the path covers blocks smaller
+ * then *logical, but it can be that extent is the
+ * first one in the file */
+
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ if (*logical < le32_to_cpu(ex->ee_block)) {
+ if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
+ EXT4_ERROR_INODE(inode,
+ "first_extent(path[%d].p_hdr) != ex",
+ depth);
+ return -EIO;
+ }
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "ix != EXT_FIRST_INDEX *logical %d!",
+ *logical);
+ return -EIO;
+ }
+ }
+ goto found_extent;
+ }
+
+ if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d < ee_block %d + ee_len %d!",
+ *logical, le32_to_cpu(ex->ee_block), ee_len);
+ return -EIO;
+ }
+
+ if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
+ /* next allocated block in this leaf */
+ ex++;
+ goto found_extent;
+ }
+
+ /* go up and search for index to the right */
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
+ goto got_index;
+ }
+
+ /* we've gone up to the root and found no index to the right */
+ return 0;
+
+got_index:
+ /* we've found index to the right, let's
+ * follow it and find the closest allocated
+ * block to the right */
+ ix++;
+ block = ext4_idx_pblock(ix);
+ while (++depth < path->p_depth) {
+ bh = sb_bread(inode->i_sb, block);
+ if (bh == NULL)
+ return -EIO;
+ eh = ext_block_hdr(bh);
+ /* subtract from p_depth to get proper eh_depth */
+ if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
+ put_bh(bh);
+ return -EIO;
+ }
+ ix = EXT_FIRST_INDEX(eh);
+ block = ext4_idx_pblock(ix);
+ put_bh(bh);
+ }
+
+ bh = sb_bread(inode->i_sb, block);
+ if (bh == NULL)
+ return -EIO;
+ eh = ext_block_hdr(bh);
+ if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
+ put_bh(bh);
+ return -EIO;
+ }
+ ex = EXT_FIRST_EXTENT(eh);
+found_extent:
+ *logical = le32_to_cpu(ex->ee_block);
+ *phys = ext4_ext_pblock(ex);
+ *ret_ex = ex;
+ if (bh)
+ put_bh(bh);
+ return 0;
+}
+
+/*
+ * ext4_ext_next_allocated_block:
+ * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
+ * NOTE: it considers block number from index entry as
+ * allocated block. Thus, index entries have to be consistent
+ * with leaves.
+ */
+static ext4_lblk_t
+ext4_ext_next_allocated_block(struct ext4_ext_path *path)
+{
+ int depth;
+
+ BUG_ON(path == NULL);
+ depth = path->p_depth;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return EXT_MAX_BLOCKS;
+
+ while (depth >= 0) {
+ if (depth == path->p_depth) {
+ /* leaf */
+ if (path[depth].p_ext &&
+ path[depth].p_ext !=
+ EXT_LAST_EXTENT(path[depth].p_hdr))
+ return le32_to_cpu(path[depth].p_ext[1].ee_block);
+ } else {
+ /* index */
+ if (path[depth].p_idx !=
+ EXT_LAST_INDEX(path[depth].p_hdr))
+ return le32_to_cpu(path[depth].p_idx[1].ei_block);
+ }
+ depth--;
+ }
+
+ return EXT_MAX_BLOCKS;
+}
+
+/*
+ * ext4_ext_next_leaf_block:
+ * returns first allocated block from next leaf or EXT_MAX_BLOCKS
+ */
+static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
+{
+ int depth;
+
+ BUG_ON(path == NULL);
+ depth = path->p_depth;
+
+ /* zero-tree has no leaf blocks at all */
+ if (depth == 0)
+ return EXT_MAX_BLOCKS;
+
+ /* go to index block */
+ depth--;
+
+ while (depth >= 0) {
+ if (path[depth].p_idx !=
+ EXT_LAST_INDEX(path[depth].p_hdr))
+ return (ext4_lblk_t)
+ le32_to_cpu(path[depth].p_idx[1].ei_block);
+ depth--;
+ }
+
+ return EXT_MAX_BLOCKS;
+}
+
+/*
+ * ext4_ext_correct_indexes:
+ * if leaf gets modified and modified extent is first in the leaf,
+ * then we have to correct all indexes above.
+ * TODO: do we need to correct tree in all cases?
+ */
+static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent_header *eh;
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+ __le32 border;
+ int k, err = 0;
+
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+
+ if (unlikely(ex == NULL || eh == NULL)) {
+ EXT4_ERROR_INODE(inode,
+ "ex %p == NULL or eh %p == NULL", ex, eh);
+ return -EIO;
+ }
+
+ if (depth == 0) {
+ /* there is no tree at all */
+ return 0;
+ }
+
+ if (ex != EXT_FIRST_EXTENT(eh)) {
+ /* we correct tree if first leaf got modified only */
+ return 0;
+ }
+
+ /*
+ * TODO: we need correction if border is smaller than current one
+ */
+ k = depth - 1;
+ border = path[depth].p_ext->ee_block;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ return err;
+ path[k].p_idx->ei_block = border;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ return err;
+
+ while (k--) {
+ /* change all left-side indexes */
+ if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
+ break;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ break;
+ path[k].p_idx->ei_block = border;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
+int
+ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
+ struct ext4_extent *ex2)
+{
+ unsigned short ext1_ee_len, ext2_ee_len, max_len;
+
+ /*
+ * Make sure that either both extents are uninitialized, or
+ * both are _not_.
+ */
+ if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
+ return 0;
+
+ if (ext4_ext_is_uninitialized(ex1))
+ max_len = EXT_UNINIT_MAX_LEN;
+ else
+ max_len = EXT_INIT_MAX_LEN;
+
+ ext1_ee_len = ext4_ext_get_actual_len(ex1);
+ ext2_ee_len = ext4_ext_get_actual_len(ex2);
+
+ if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
+ le32_to_cpu(ex2->ee_block))
+ return 0;
+
+ /*
+ * To allow future support for preallocated extents to be added
+ * as an RO_COMPAT feature, refuse to merge to extents if
+ * this can result in the top bit of ee_len being set.
+ */
+ if (ext1_ee_len + ext2_ee_len > max_len)
+ return 0;
+#ifdef AGGRESSIVE_TEST
+ if (ext1_ee_len >= 4)
+ return 0;
+#endif
+
+ if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
+ return 1;
+ return 0;
+}
+
+/*
+ * This function tries to merge the "ex" extent to the next extent in the tree.
+ * It always tries to merge towards right. If you want to merge towards
+ * left, pass "ex - 1" as argument instead of "ex".
+ * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
+ * 1 if they got merged.
+ */
+static int ext4_ext_try_to_merge_right(struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex)
+{
+ struct ext4_extent_header *eh;
+ unsigned int depth, len;
+ int merge_done = 0;
+ int uninitialized = 0;
+
+ depth = ext_depth(inode);
+ BUG_ON(path[depth].p_hdr == NULL);
+ eh = path[depth].p_hdr;
+
+ while (ex < EXT_LAST_EXTENT(eh)) {
+ if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
+ break;
+ /* merge with next extent! */
+ if (ext4_ext_is_uninitialized(ex))
+ uninitialized = 1;
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(ex + 1));
+ if (uninitialized)
+ ext4_ext_mark_uninitialized(ex);
+
+ if (ex + 1 < EXT_LAST_EXTENT(eh)) {
+ len = (EXT_LAST_EXTENT(eh) - ex - 1)
+ * sizeof(struct ext4_extent);
+ memmove(ex + 1, ex + 2, len);
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ merge_done = 1;
+ WARN_ON(eh->eh_entries == 0);
+ if (!eh->eh_entries)
+ EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
+ }
+
+ return merge_done;
+}
+
+/*
+ * This function tries to merge the @ex extent to neighbours in the tree.
+ * return 1 if merge left else 0.
+ */
+static int ext4_ext_try_to_merge(struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex) {
+ struct ext4_extent_header *eh;
+ unsigned int depth;
+ int merge_done = 0;
+ int ret = 0;
+
+ depth = ext_depth(inode);
+ BUG_ON(path[depth].p_hdr == NULL);
+ eh = path[depth].p_hdr;
+
+ if (ex > EXT_FIRST_EXTENT(eh))
+ merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
+
+ if (!merge_done)
+ ret = ext4_ext_try_to_merge_right(inode, path, ex);
+
+ return ret;
+}
+
+/*
+ * check if a portion of the "newext" extent overlaps with an
+ * existing extent.
+ *
+ * If there is an overlap discovered, it updates the length of the newext
+ * such that there will be no overlap, and then returns 1.
+ * If there is no overlap found, it returns 0.
+ */
+static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
+ struct inode *inode,
+ struct ext4_extent *newext,
+ struct ext4_ext_path *path)
+{
+ ext4_lblk_t b1, b2;
+ unsigned int depth, len1;
+ unsigned int ret = 0;
+
+ b1 = le32_to_cpu(newext->ee_block);
+ len1 = ext4_ext_get_actual_len(newext);
+ depth = ext_depth(inode);
+ if (!path[depth].p_ext)
+ goto out;
+ b2 = le32_to_cpu(path[depth].p_ext->ee_block);
+ b2 &= ~(sbi->s_cluster_ratio - 1);
+
+ /*
+ * get the next allocated block if the extent in the path
+ * is before the requested block(s)
+ */
+ if (b2 < b1) {
+ b2 = ext4_ext_next_allocated_block(path);
+ if (b2 == EXT_MAX_BLOCKS)
+ goto out;
+ b2 &= ~(sbi->s_cluster_ratio - 1);
+ }
+
+ /* check for wrap through zero on extent logical start block*/
+ if (b1 + len1 < b1) {
+ len1 = EXT_MAX_BLOCKS - b1;
+ newext->ee_len = cpu_to_le16(len1);
+ ret = 1;
+ }
+
+ /* check for overlap */
+ if (b1 + len1 > b2) {
+ newext->ee_len = cpu_to_le16(b2 - b1);
+ ret = 1;
+ }
+out:
+ return ret;
+}
+
+/*
+ * ext4_ext_insert_extent:
+ * tries to merge requsted extent into the existing extent or
+ * inserts requested extent as new one into the tree,
+ * creating new leaf in the no-space case.
+ */
+int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext, int flag)
+{
+ struct ext4_extent_header *eh;
+ struct ext4_extent *ex, *fex;
+ struct ext4_extent *nearex; /* nearest extent */
+ struct ext4_ext_path *npath = NULL;
+ int depth, len, err;
+ ext4_lblk_t next;
+ unsigned uninitialized = 0;
+ int flags = 0;
+
+ if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
+ EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
+ return -EIO;
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ return -EIO;
+ }
+
+ /* try to insert block into found extent and return */
+ if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
+ && ext4_can_extents_be_merged(inode, ex, newext)) {
+ ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
+ ext4_ext_is_uninitialized(newext),
+ ext4_ext_get_actual_len(newext),
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_is_uninitialized(ex),
+ ext4_ext_get_actual_len(ex),
+ ext4_ext_pblock(ex));
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ return err;
+
+ /*
+ * ext4_can_extents_be_merged should have checked that either
+ * both extents are uninitialized, or both aren't. Thus we
+ * need to check only one of them here.
+ */
+ if (ext4_ext_is_uninitialized(ex))
+ uninitialized = 1;
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(newext));
+ if (uninitialized)
+ ext4_ext_mark_uninitialized(ex);
+ eh = path[depth].p_hdr;
+ nearex = ex;
+ goto merge;
+ }
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
+ goto has_space;
+
+ /* probably next leaf has space for us? */
+ fex = EXT_LAST_EXTENT(eh);
+ next = EXT_MAX_BLOCKS;
+ if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
+ next = ext4_ext_next_leaf_block(path);
+ if (next != EXT_MAX_BLOCKS) {
+ ext_debug("next leaf block - %u\n", next);
+ BUG_ON(npath != NULL);
+ npath = ext4_ext_find_extent(inode, next, NULL);
+ if (IS_ERR(npath))
+ return PTR_ERR(npath);
+ BUG_ON(npath->p_depth != path->p_depth);
+ eh = npath[depth].p_hdr;
+ if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
+ ext_debug("next leaf isn't full(%d)\n",
+ le16_to_cpu(eh->eh_entries));
+ path = npath;
+ goto has_space;
+ }
+ ext_debug("next leaf has no free space(%d,%d)\n",
+ le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+ }
+
+ /*
+ * There is no free space in the found leaf.
+ * We're gonna add a new leaf in the tree.
+ */
+ if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
+ flags = EXT4_MB_USE_ROOT_BLOCKS;
+ err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
+ if (err)
+ goto cleanup;
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+
+has_space:
+ nearex = path[depth].p_ext;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+
+ if (!nearex) {
+ /* there is no extent in this leaf, create first one */
+ ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_uninitialized(newext),
+ ext4_ext_get_actual_len(newext));
+ nearex = EXT_FIRST_EXTENT(eh);
+ } else {
+ if (le32_to_cpu(newext->ee_block)
+ > le32_to_cpu(nearex->ee_block)) {
+ /* Insert after */
+ ext_debug("insert %u:%llu:[%d]%d before: "
+ "nearest %p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_uninitialized(newext),
+ ext4_ext_get_actual_len(newext),
+ nearex);
+ nearex++;
+ } else {
+ /* Insert before */
+ BUG_ON(newext->ee_block == nearex->ee_block);
+ ext_debug("insert %u:%llu:[%d]%d after: "
+ "nearest %p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_uninitialized(newext),
+ ext4_ext_get_actual_len(newext),
+ nearex);
+ }
+ len = EXT_LAST_EXTENT(eh) - nearex + 1;
+ if (len > 0) {
+ ext_debug("insert %u:%llu:[%d]%d: "
+ "move %d extents from 0x%p to 0x%p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_uninitialized(newext),
+ ext4_ext_get_actual_len(newext),
+ len, nearex, nearex + 1);
+ memmove(nearex + 1, nearex,
+ len * sizeof(struct ext4_extent));
+ }
+ }
+
+ le16_add_cpu(&eh->eh_entries, 1);
+ path[depth].p_ext = nearex;
+ nearex->ee_block = newext->ee_block;
+ ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
+ nearex->ee_len = newext->ee_len;
+
+merge:
+ /* try to merge extents to the right */
+ if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
+ ext4_ext_try_to_merge(inode, path, nearex);
+
+ /* try to merge extents to the left */
+
+ /* time to correct all indexes above */
+ err = ext4_ext_correct_indexes(handle, inode, path);
+ if (err)
+ goto cleanup;
+
+ err = ext4_ext_dirty(handle, inode, path + depth);
+
+cleanup:
+ if (npath) {
+ ext4_ext_drop_refs(npath);
+ kfree(npath);
+ }
+ ext4_ext_invalidate_cache(inode);
+ return err;
+}
+
+static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
+ ext4_lblk_t num, ext_prepare_callback func,
+ void *cbdata)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_ext_cache cbex;
+ struct ext4_extent *ex;
+ ext4_lblk_t next, start = 0, end = 0;
+ ext4_lblk_t last = block + num;
+ int depth, exists, err = 0;
+
+ BUG_ON(func == NULL);
+ BUG_ON(inode == NULL);
+
+ while (block < last && block != EXT_MAX_BLOCKS) {
+ num = last - block;
+ /* find extent for this block */
+ down_read(&EXT4_I(inode)->i_data_sem);
+ path = ext4_ext_find_extent(inode, block, path);
+ up_read(&EXT4_I(inode)->i_data_sem);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ break;
+ }
+
+ depth = ext_depth(inode);
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ err = -EIO;
+ break;
+ }
+ ex = path[depth].p_ext;
+ next = ext4_ext_next_allocated_block(path);
+
+ exists = 0;
+ if (!ex) {
+ /* there is no extent yet, so try to allocate
+ * all requested space */
+ start = block;
+ end = block + num;
+ } else if (le32_to_cpu(ex->ee_block) > block) {
+ /* need to allocate space before found extent */
+ start = block;
+ end = le32_to_cpu(ex->ee_block);
+ if (block + num < end)
+ end = block + num;
+ } else if (block >= le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex)) {
+ /* need to allocate space after found extent */
+ start = block;
+ end = block + num;
+ if (end >= next)
+ end = next;
+ } else if (block >= le32_to_cpu(ex->ee_block)) {
+ /*
+ * some part of requested space is covered
+ * by found extent
+ */
+ start = block;
+ end = le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex);
+ if (block + num < end)
+ end = block + num;
+ exists = 1;
+ } else {
+ BUG();
+ }
+ BUG_ON(end <= start);
+
+ if (!exists) {
+ cbex.ec_block = start;
+ cbex.ec_len = end - start;
+ cbex.ec_start = 0;
+ } else {
+ cbex.ec_block = le32_to_cpu(ex->ee_block);
+ cbex.ec_len = ext4_ext_get_actual_len(ex);
+ cbex.ec_start = ext4_ext_pblock(ex);
+ }
+
+ if (unlikely(cbex.ec_len == 0)) {
+ EXT4_ERROR_INODE(inode, "cbex.ec_len == 0");
+ err = -EIO;
+ break;
+ }
+ err = func(inode, next, &cbex, ex, cbdata);
+ ext4_ext_drop_refs(path);
+
+ if (err < 0)
+ break;
+
+ if (err == EXT_REPEAT)
+ continue;
+ else if (err == EXT_BREAK) {
+ err = 0;
+ break;
+ }
+
+ if (ext_depth(inode) != depth) {
+ /* depth was changed. we have to realloc path */
+ kfree(path);
+ path = NULL;
+ }
+
+ block = cbex.ec_block + cbex.ec_len;
+ }
+
+ if (path) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+
+ return err;
+}
+
+static void
+ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
+ __u32 len, ext4_fsblk_t start)
+{
+ struct ext4_ext_cache *cex;
+ BUG_ON(len == 0);
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+ trace_ext4_ext_put_in_cache(inode, block, len, start);
+ cex = &EXT4_I(inode)->i_cached_extent;
+ cex->ec_block = block;
+ cex->ec_len = len;
+ cex->ec_start = start;
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+}
+
+/*
+ * ext4_ext_put_gap_in_cache:
+ * calculate boundaries of the gap that the requested block fits into
+ * and cache this gap
+ */
+static void
+ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
+ ext4_lblk_t block)
+{
+ int depth = ext_depth(inode);
+ unsigned long len;
+ ext4_lblk_t lblock;
+ struct ext4_extent *ex;
+
+ ex = path[depth].p_ext;
+ if (ex == NULL) {
+ /* there is no extent yet, so gap is [0;-] */
+ lblock = 0;
+ len = EXT_MAX_BLOCKS;
+ ext_debug("cache gap(whole file):");
+ } else if (block < le32_to_cpu(ex->ee_block)) {
+ lblock = block;
+ len = le32_to_cpu(ex->ee_block) - block;
+ ext_debug("cache gap(before): %u [%u:%u]",
+ block,
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_get_actual_len(ex));
+ } else if (block >= le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex)) {
+ ext4_lblk_t next;
+ lblock = le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex);
+
+ next = ext4_ext_next_allocated_block(path);
+ ext_debug("cache gap(after): [%u:%u] %u",
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_get_actual_len(ex),
+ block);
+ BUG_ON(next == lblock);
+ len = next - lblock;
+ } else {
+ lblock = len = 0;
+ BUG();
+ }
+
+ ext_debug(" -> %u:%lu\n", lblock, len);
+ ext4_ext_put_in_cache(inode, lblock, len, 0);
+}
+
+/*
+ * ext4_ext_check_cache()
+ * Checks to see if the given block is in the cache.
+ * If it is, the cached extent is stored in the given
+ * cache extent pointer. If the cached extent is a hole,
+ * this routine should be used instead of
+ * ext4_ext_in_cache if the calling function needs to
+ * know the size of the hole.
+ *
+ * @inode: The files inode
+ * @block: The block to look for in the cache
+ * @ex: Pointer where the cached extent will be stored
+ * if it contains block
+ *
+ * Return 0 if cache is invalid; 1 if the cache is valid
+ */
+static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block,
+ struct ext4_ext_cache *ex){
+ struct ext4_ext_cache *cex;
+ struct ext4_sb_info *sbi;
+ int ret = 0;
+
+ /*
+ * We borrow i_block_reservation_lock to protect i_cached_extent
+ */
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+ cex = &EXT4_I(inode)->i_cached_extent;
+ sbi = EXT4_SB(inode->i_sb);
+
+ /* has cache valid data? */
+ if (cex->ec_len == 0)
+ goto errout;
+
+ if (in_range(block, cex->ec_block, cex->ec_len)) {
+ memcpy(ex, cex, sizeof(struct ext4_ext_cache));
+ ext_debug("%u cached by %u:%u:%llu\n",
+ block,
+ cex->ec_block, cex->ec_len, cex->ec_start);
+ ret = 1;
+ }
+errout:
+ trace_ext4_ext_in_cache(inode, block, ret);
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+ return ret;
+}
+
+/*
+ * ext4_ext_in_cache()
+ * Checks to see if the given block is in the cache.
+ * If it is, the cached extent is stored in the given
+ * extent pointer.
+ *
+ * @inode: The files inode
+ * @block: The block to look for in the cache
+ * @ex: Pointer where the cached extent will be stored
+ * if it contains block
+ *
+ * Return 0 if cache is invalid; 1 if the cache is valid
+ */
+static int
+ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
+ struct ext4_extent *ex)
+{
+ struct ext4_ext_cache cex;
+ int ret = 0;
+
+ if (ext4_ext_check_cache(inode, block, &cex)) {
+ ex->ee_block = cpu_to_le32(cex.ec_block);
+ ext4_ext_store_pblock(ex, cex.ec_start);
+ ex->ee_len = cpu_to_le16(cex.ec_len);
+ ret = 1;
+ }
+
+ return ret;
+}
+
+
+/*
+ * ext4_ext_rm_idx:
+ * removes index from the index block.
+ */
+static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path, int depth)
+{
+ int err;
+ ext4_fsblk_t leaf;
+
+ /* free index block */
+ depth--;
+ path = path + depth;
+ leaf = ext4_idx_pblock(path->p_idx);
+ if (unlikely(path->p_hdr->eh_entries == 0)) {
+ EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
+ return -EIO;
+ }
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err)
+ return err;
+
+ if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
+ int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
+ len *= sizeof(struct ext4_extent_idx);
+ memmove(path->p_idx, path->p_idx + 1, len);
+ }
+
+ le16_add_cpu(&path->p_hdr->eh_entries, -1);
+ err = ext4_ext_dirty(handle, inode, path);
+ if (err)
+ return err;
+ ext_debug("index is empty, remove it, free block %llu\n", leaf);
+ trace_ext4_ext_rm_idx(inode, leaf);
+
+ ext4_free_blocks(handle, inode, NULL, leaf, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
+
+ while (--depth >= 0) {
+ if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
+ break;
+ path--;
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err)
+ break;
+ path->p_idx->ei_block = (path+1)->p_idx->ei_block;
+ err = ext4_ext_dirty(handle, inode, path);
+ if (err)
+ break;
+ }
+ return err;
+}
+
+/*
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
+ */
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
+ struct ext4_ext_path *path)
+{
+ if (path) {
+ int depth = ext_depth(inode);
+ int ret = 0;
+
+ /* probably there is space in leaf? */
+ if (le16_to_cpu(path[depth].p_hdr->eh_entries)
+ < le16_to_cpu(path[depth].p_hdr->eh_max)) {
+
+ /*
+ * There are some space in the leaf tree, no
+ * need to account for leaf block credit
+ *
+ * bitmaps and block group descriptor blocks
+ * and other metadata blocks still need to be
+ * accounted.
+ */
+ /* 1 bitmap, 1 block group descriptor */
+ ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+ return ret;
+ }
+ }
+
+ return ext4_chunk_trans_blocks(inode, nrblocks);
+}
+
+/*
+ * How many index/leaf blocks need to change/allocate to modify nrblocks?
+ *
+ * if nrblocks are fit in a single extent (chunk flag is 1), then
+ * in the worse case, each tree level index/leaf need to be changed
+ * if the tree split due to insert a new extent, then the old tree
+ * index/leaf need to be updated too
+ *
+ * If the nrblocks are discontiguous, they could cause
+ * the whole tree split more than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+ int index;
+ int depth = ext_depth(inode);
+
+ if (chunk)
+ index = depth * 2;
+ else
+ index = depth * 3;
+
+ return index;
+}
+
+static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_extent *ex,
+ ext4_fsblk_t *partial_cluster,
+ ext4_lblk_t from, ext4_lblk_t to)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ unsigned short ee_len = ext4_ext_get_actual_len(ex);
+ ext4_fsblk_t pblk;
+ int flags = EXT4_FREE_BLOCKS_FORGET;
+
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+ flags |= EXT4_FREE_BLOCKS_METADATA;
+ /*
+ * For bigalloc file systems, we never free a partial cluster
+ * at the beginning of the extent. Instead, we make a note
+ * that we tried freeing the cluster, and check to see if we
+ * need to free it on a subsequent call to ext4_remove_blocks,
+ * or at the end of the ext4_truncate() operation.
+ */
+ flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
+
+ trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
+ /*
+ * If we have a partial cluster, and it's different from the
+ * cluster of the last block, we need to explicitly free the
+ * partial cluster here.
+ */
+ pblk = ext4_ext_pblock(ex) + ee_len - 1;
+ if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, *partial_cluster),
+ sbi->s_cluster_ratio, flags);
+ *partial_cluster = 0;
+ }
+
+#ifdef EXTENTS_STATS
+ {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ spin_lock(&sbi->s_ext_stats_lock);
+ sbi->s_ext_blocks += ee_len;
+ sbi->s_ext_extents++;
+ if (ee_len < sbi->s_ext_min)
+ sbi->s_ext_min = ee_len;
+ if (ee_len > sbi->s_ext_max)
+ sbi->s_ext_max = ee_len;
+ if (ext_depth(inode) > sbi->s_depth_max)
+ sbi->s_depth_max = ext_depth(inode);
+ spin_unlock(&sbi->s_ext_stats_lock);
+ }
+#endif
+ if (from >= le32_to_cpu(ex->ee_block)
+ && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
+ /* tail removal */
+ ext4_lblk_t num;
+
+ num = le32_to_cpu(ex->ee_block) + ee_len - from;
+ pblk = ext4_ext_pblock(ex) + ee_len - num;
+ ext_debug("free last %u blocks starting %llu\n", num, pblk);
+ ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
+ /*
+ * If the block range to be freed didn't start at the
+ * beginning of a cluster, and we removed the entire
+ * extent, save the partial cluster here, since we
+ * might need to delete if we determine that the
+ * truncate operation has removed all of the blocks in
+ * the cluster.
+ */
+ if (pblk & (sbi->s_cluster_ratio - 1) &&
+ (ee_len == num))
+ *partial_cluster = EXT4_B2C(sbi, pblk);
+ else
+ *partial_cluster = 0;
+ } else if (from == le32_to_cpu(ex->ee_block)
+ && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
+ /* head removal */
+ ext4_lblk_t num;
+ ext4_fsblk_t start;
+
+ num = to - from;
+ start = ext4_ext_pblock(ex);
+
+ ext_debug("free first %u blocks starting %llu\n", num, start);
+ ext4_free_blocks(handle, inode, NULL, start, num, flags);
+
+ } else {
+ printk(KERN_INFO "strange request: removal(2) "
+ "%u-%u from %u:%u\n",
+ from, to, le32_to_cpu(ex->ee_block), ee_len);
+ }
+ return 0;
+}
+
+
+/*
+ * ext4_ext_rm_leaf() Removes the extents associated with the
+ * blocks appearing between "start" and "end", and splits the extents
+ * if "start" and "end" appear in the same extent
+ *
+ * @handle: The journal handle
+ * @inode: The files inode
+ * @path: The path to the leaf
+ * @start: The first block to remove
+ * @end: The last block to remove
+ */
+static int
+ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
+ ext4_lblk_t start, ext4_lblk_t end)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int err = 0, correct_index = 0;
+ int depth = ext_depth(inode), credits;
+ struct ext4_extent_header *eh;
+ ext4_lblk_t a, b;
+ unsigned num;
+ ext4_lblk_t ex_ee_block;
+ unsigned short ex_ee_len;
+ unsigned uninitialized = 0;
+ struct ext4_extent *ex;
+
+ /* the header must be checked already in ext4_ext_remove_space() */
+ ext_debug("truncate since %u in leaf to %u\n", start, end);
+ if (!path[depth].p_hdr)
+ path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
+ eh = path[depth].p_hdr;
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ return -EIO;
+ }
+ /* find where to start removing */
+ ex = EXT_LAST_EXTENT(eh);
+
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+
+ trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
+
+ while (ex >= EXT_FIRST_EXTENT(eh) &&
+ ex_ee_block + ex_ee_len > start) {
+
+ if (ext4_ext_is_uninitialized(ex))
+ uninitialized = 1;
+ else
+ uninitialized = 0;
+
+ ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
+ uninitialized, ex_ee_len);
+ path[depth].p_ext = ex;
+
+ a = ex_ee_block > start ? ex_ee_block : start;
+ b = ex_ee_block+ex_ee_len - 1 < end ?
+ ex_ee_block+ex_ee_len - 1 : end;
+
+ ext_debug(" border %u:%u\n", a, b);
+
+ /* If this extent is beyond the end of the hole, skip it */
+ if (end < ex_ee_block) {
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ continue;
+ } else if (b != ex_ee_block + ex_ee_len - 1) {
+ EXT4_ERROR_INODE(inode,
+ "can not handle truncate %u:%u "
+ "on extent %u:%u",
+ start, end, ex_ee_block,
+ ex_ee_block + ex_ee_len - 1);
+ err = -EIO;
+ goto out;
+ } else if (a != ex_ee_block) {
+ /* remove tail of the extent */
+ num = a - ex_ee_block;
+ } else {
+ /* remove whole extent: excellent! */
+ num = 0;
+ }
+ /*
+ * 3 for leaf, sb, and inode plus 2 (bmap and group
+ * descriptor) for each block group; assume two block
+ * groups plus ex_ee_len/blocks_per_block_group for
+ * the worst case
+ */
+ credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
+ if (ex == EXT_FIRST_EXTENT(eh)) {
+ correct_index = 1;
+ credits += (ext_depth(inode)) + 1;
+ }
+ credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
+
+ err = ext4_ext_truncate_extend_restart(handle, inode, credits);
+ if (err)
+ goto out;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
+ a, b);
+ if (err)
+ goto out;
+
+ if (num == 0)
+ /* this extent is removed; mark slot entirely unused */
+ ext4_ext_store_pblock(ex, 0);
+
+ ex->ee_len = cpu_to_le16(num);
+ /*
+ * Do not mark uninitialized if all the blocks in the
+ * extent have been removed.
+ */
+ if (uninitialized && num)
+ ext4_ext_mark_uninitialized(ex);
+ /*
+ * If the extent was completely released,
+ * we need to remove it from the leaf
+ */
+ if (num == 0) {
+ if (end != EXT_MAX_BLOCKS - 1) {
+ /*
+ * For hole punching, we need to scoot all the
+ * extents up when an extent is removed so that
+ * we dont have blank extents in the middle
+ */
+ memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
+ sizeof(struct ext4_extent));
+
+ /* Now get rid of the one at the end */
+ memset(EXT_LAST_EXTENT(eh), 0,
+ sizeof(struct ext4_extent));
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ } else
+ *partial_cluster = 0;
+
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
+ ext4_ext_pblock(ex));
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ }
+
+ if (correct_index && eh->eh_entries)
+ err = ext4_ext_correct_indexes(handle, inode, path);
+
+ /*
+ * If there is still a entry in the leaf node, check to see if
+ * it references the partial cluster. This is the only place
+ * where it could; if it doesn't, we can free the cluster.
+ */
+ if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
+ (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
+ *partial_cluster)) {
+ int flags = EXT4_FREE_BLOCKS_FORGET;
+
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+ flags |= EXT4_FREE_BLOCKS_METADATA;
+
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, *partial_cluster),
+ sbi->s_cluster_ratio, flags);
+ *partial_cluster = 0;
+ }
+
+ /* if this leaf is free, then we should
+ * remove it from index block above */
+ if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
+ err = ext4_ext_rm_idx(handle, inode, path, depth);
+
+out:
+ return err;
+}
+
+/*
+ * ext4_ext_more_to_rm:
+ * returns 1 if current index has to be freed (even partial)
+ */
+static int
+ext4_ext_more_to_rm(struct ext4_ext_path *path)
+{
+ BUG_ON(path->p_idx == NULL);
+
+ if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
+ return 0;
+
+ /*
+ * if truncate on deeper level happened, it wasn't partial,
+ * so we have to consider current index for truncation
+ */
+ if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
+ return 0;
+ return 1;
+}
+
+static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
+ ext4_lblk_t end)
+{
+ struct super_block *sb = inode->i_sb;
+ int depth = ext_depth(inode);
+ struct ext4_ext_path *path = NULL;
+ ext4_fsblk_t partial_cluster = 0;
+ handle_t *handle;
+ int i = 0, err;
+
+ ext_debug("truncate since %u to %u\n", start, end);
+
+ /* probably first extent we're gonna free will be last in block */
+ handle = ext4_journal_start(inode, depth + 1);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+again:
+ ext4_ext_invalidate_cache(inode);
+
+ trace_ext4_ext_remove_space(inode, start, depth);
+
+ /*
+ * Check if we are removing extents inside the extent tree. If that
+ * is the case, we are going to punch a hole inside the extent tree
+ * so we have to check whether we need to split the extent covering
+ * the last block to remove so we can easily remove the part of it
+ * in ext4_ext_rm_leaf().
+ */
+ if (end < EXT_MAX_BLOCKS - 1) {
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+
+ /* find extent for this block */
+ path = ext4_ext_find_extent(inode, end, NULL);
+ if (IS_ERR(path)) {
+ ext4_journal_stop(handle);
+ return PTR_ERR(path);
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (!ex) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ path = NULL;
+ goto cont;
+ }
+
+ ee_block = le32_to_cpu(ex->ee_block);
+
+ /*
+ * See if the last block is inside the extent, if so split
+ * the extent at 'end' block so we can easily remove the
+ * tail of the first part of the split extent in
+ * ext4_ext_rm_leaf().
+ */
+ if (end >= ee_block &&
+ end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
+ int split_flag = 0;
+
+ if (ext4_ext_is_uninitialized(ex))
+ split_flag = EXT4_EXT_MARK_UNINIT1 |
+ EXT4_EXT_MARK_UNINIT2;
+
+ /*
+ * Split the extent in two so that 'end' is the last
+ * block in the first new extent
+ */
+ err = ext4_split_extent_at(handle, inode, path,
+ end + 1, split_flag,
+ EXT4_GET_BLOCKS_PRE_IO |
+ EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
+
+ if (err < 0)
+ goto out;
+ }
+ }
+cont:
+
+ /*
+ * We start scanning from right side, freeing all the blocks
+ * after i_size and walking into the tree depth-wise.
+ */
+ depth = ext_depth(inode);
+ if (path) {
+ int k = i = depth;
+ while (--k > 0)
+ path[k].p_block =
+ le16_to_cpu(path[k].p_hdr->eh_entries)+1;
+ } else {
+ path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
+ GFP_NOFS);
+ if (path == NULL) {
+ ext4_journal_stop(handle);
+ return -ENOMEM;
+ }
+ path[0].p_depth = depth;
+ path[0].p_hdr = ext_inode_hdr(inode);
+ i = 0;
+
+ if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
+ err = -EIO;
+ goto out;
+ }
+ }
+ err = 0;
+
+ while (i >= 0 && err == 0) {
+ if (i == depth) {
+ /* this is leaf block */
+ err = ext4_ext_rm_leaf(handle, inode, path,
+ &partial_cluster, start,
+ end);
+ /* root level has p_bh == NULL, brelse() eats this */
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ continue;
+ }
+
+ /* this is index block */
+ if (!path[i].p_hdr) {
+ ext_debug("initialize header\n");
+ path[i].p_hdr = ext_block_hdr(path[i].p_bh);
+ }
+
+ if (!path[i].p_idx) {
+ /* this level hasn't been touched yet */
+ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
+ ext_debug("init index ptr: hdr 0x%p, num %d\n",
+ path[i].p_hdr,
+ le16_to_cpu(path[i].p_hdr->eh_entries));
+ } else {
+ /* we were already here, see at next index */
+ path[i].p_idx--;
+ }
+
+ ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
+ i, EXT_FIRST_INDEX(path[i].p_hdr),
+ path[i].p_idx);
+ if (ext4_ext_more_to_rm(path + i)) {
+ struct buffer_head *bh;
+ /* go to the next level */
+ ext_debug("move to level %d (block %llu)\n",
+ i + 1, ext4_idx_pblock(path[i].p_idx));
+ memset(path + i + 1, 0, sizeof(*path));
+ bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
+ if (!bh) {
+ /* should we reset i_size? */
+ err = -EIO;
+ break;
+ }
+ if (WARN_ON(i + 1 > depth)) {
+ err = -EIO;
+ break;
+ }
+ if (ext4_ext_check(inode, ext_block_hdr(bh),
+ depth - i - 1)) {
+ err = -EIO;
+ break;
+ }
+ path[i + 1].p_bh = bh;
+
+ /* save actual number of indexes since this
+ * number is changed at the next iteration */
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
+ i++;
+ } else {
+ /* we finished processing this index, go up */
+ if (path[i].p_hdr->eh_entries == 0 && i > 0) {
+ /* index is empty, remove it;
+ * handle must be already prepared by the
+ * truncatei_leaf() */
+ err = ext4_ext_rm_idx(handle, inode, path, i);
+ }
+ /* root level has p_bh == NULL, brelse() eats this */
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ ext_debug("return to level %d\n", i);
+ }
+ }
+
+ trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
+ path->p_hdr->eh_entries);
+
+ /* If we still have something in the partial cluster and we have removed
+ * even the first extent, then we should free the blocks in the partial
+ * cluster as well. */
+ if (partial_cluster && path->p_hdr->eh_entries == 0) {
+ int flags = EXT4_FREE_BLOCKS_FORGET;
+
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+ flags |= EXT4_FREE_BLOCKS_METADATA;
+
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(EXT4_SB(sb), partial_cluster),
+ EXT4_SB(sb)->s_cluster_ratio, flags);
+ partial_cluster = 0;
+ }
+
+ /* TODO: flexible tree reduction should be here */
+ if (path->p_hdr->eh_entries == 0) {
+ /*
+ * truncate to zero freed all the tree,
+ * so we need to correct eh_depth
+ */
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err == 0) {
+ ext_inode_hdr(inode)->eh_depth = 0;
+ ext_inode_hdr(inode)->eh_max =
+ cpu_to_le16(ext4_ext_space_root(inode, 0));
+ err = ext4_ext_dirty(handle, inode, path);
+ }
+ }
+out:
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ if (err == -EAGAIN) {
+ path = NULL;
+ goto again;
+ }
+ ext4_journal_stop(handle);
+
+ return err;
+}
+
+/*
+ * called at mount time
+ */
+void ext4_ext_init(struct super_block *sb)
+{
+ /*
+ * possible initialization would be here
+ */
+
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
+#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
+ printk(KERN_INFO "EXT4-fs: file extents enabled"
+#ifdef AGGRESSIVE_TEST
+ ", aggressive tests"
+#endif
+#ifdef CHECK_BINSEARCH
+ ", check binsearch"
+#endif
+#ifdef EXTENTS_STATS
+ ", stats"
+#endif
+ "\n");
+#endif
+#ifdef EXTENTS_STATS
+ spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
+ EXT4_SB(sb)->s_ext_min = 1 << 30;
+ EXT4_SB(sb)->s_ext_max = 0;
+#endif
+ }
+}
+
+/*
+ * called at umount time
+ */
+void ext4_ext_release(struct super_block *sb)
+{
+ if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
+ return;
+
+#ifdef EXTENTS_STATS
+ if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
+ sbi->s_ext_blocks, sbi->s_ext_extents,
+ sbi->s_ext_blocks / sbi->s_ext_extents);
+ printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
+ sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
+ }
+#endif
+}
+
+/* FIXME!! we need to try to merge to left or right after zero-out */
+static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
+{
+ ext4_fsblk_t ee_pblock;
+ unsigned int ee_len;
+ int ret;
+
+ ee_len = ext4_ext_get_actual_len(ex);
+ ee_pblock = ext4_ext_pblock(ex);
+
+ ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
+ if (ret > 0)
+ ret = 0;
+
+ return ret;
+}
+
+/*
+ * ext4_split_extent_at() splits an extent at given block.
+ *
+ * @handle: the journal handle
+ * @inode: the file inode
+ * @path: the path to the extent
+ * @split: the logical block where the extent is splitted.
+ * @split_flags: indicates if the extent could be zeroout if split fails, and
+ * the states(init or uninit) of new extents.
+ * @flags: flags used to insert new extent to extent tree.
+ *
+ *
+ * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
+ * of which are deterimined by split_flag.
+ *
+ * There are two cases:
+ * a> the extent are splitted into two extent.
+ * b> split is not needed, and just mark the extent.
+ *
+ * return 0 on success.
+ */
+static int ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t split,
+ int split_flag,
+ int flags)
+{
+ ext4_fsblk_t newblock;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex, newex, orig_ex;
+ struct ext4_extent *ex2 = NULL;
+ unsigned int ee_len, depth;
+ int err = 0;
+
+ BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
+ (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
+
+ ext_debug("ext4_split_extents_at: inode %lu, logical"
+ "block %llu\n", inode->i_ino, (unsigned long long)split);
+
+ ext4_ext_show_leaf(inode, path);
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ newblock = split - ee_block + ext4_ext_pblock(ex);
+
+ BUG_ON(split < ee_block || split >= (ee_block + ee_len));
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (split == ee_block) {
+ /*
+ * case b: block @split is the block that the extent begins with
+ * then we just change the state of the extent, and splitting
+ * is not needed.
+ */
+ if (split_flag & EXT4_EXT_MARK_UNINIT2)
+ ext4_ext_mark_uninitialized(ex);
+ else
+ ext4_ext_mark_initialized(ex);
+
+ if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
+ ext4_ext_try_to_merge(inode, path, ex);
+
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ goto out;
+ }
+
+ /* case a */
+ memcpy(&orig_ex, ex, sizeof(orig_ex));
+ ex->ee_len = cpu_to_le16(split - ee_block);
+ if (split_flag & EXT4_EXT_MARK_UNINIT1)
+ ext4_ext_mark_uninitialized(ex);
+
+ /*
+ * path may lead to new leaf, not to original leaf any more
+ * after ext4_ext_insert_extent() returns,
+ */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto fix_extent_len;
+
+ ex2 = &newex;
+ ex2->ee_block = cpu_to_le32(split);
+ ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
+ ext4_ext_store_pblock(ex2, newblock);
+ if (split_flag & EXT4_EXT_MARK_UNINIT2)
+ ext4_ext_mark_uninitialized(ex2);
+
+ err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+ if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
+ if (split_flag & EXT4_EXT_DATA_VALID1)
+ err = ext4_ext_zeroout(inode, ex2);
+ else
+ err = ext4_ext_zeroout(inode, ex);
+ } else
+ err = ext4_ext_zeroout(inode, &orig_ex);
+
+ if (err)
+ goto fix_extent_len;
+ /* update the extent length and mark as initialized */
+ ex->ee_len = cpu_to_le16(ee_len);
+ ext4_ext_try_to_merge(inode, path, ex);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ goto out;
+ } else if (err)
+ goto fix_extent_len;
+
+out:
+ ext4_ext_show_leaf(inode, path);
+ return err;
+
+fix_extent_len:
+ ex->ee_len = orig_ex.ee_len;
+ ext4_ext_dirty(handle, inode, path + depth);
+ return err;
+}
+
+/*
+ * ext4_split_extents() splits an extent and mark extent which is covered
+ * by @map as split_flags indicates
+ *
+ * It may result in splitting the extent into multiple extents (upto three)
+ * There are three possibilities:
+ * a> There is no split required
+ * b> Splits in two extents: Split is happening at either end of the extent
+ * c> Splits in three extents: Somone is splitting in middle of the extent
+ *
+ */
+static int ext4_split_extent(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_map_blocks *map,
+ int split_flag,
+ int flags)
+{
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len, depth;
+ int err = 0;
+ int uninitialized;
+ int split_flag1, flags1;
+ int allocated = map->m_len;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ uninitialized = ext4_ext_is_uninitialized(ex);
+
+ if (map->m_lblk + map->m_len < ee_block + ee_len) {
+ split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
+ flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
+ if (uninitialized)
+ split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
+ EXT4_EXT_MARK_UNINIT2;
+ if (split_flag & EXT4_EXT_DATA_VALID2)
+ split_flag1 |= EXT4_EXT_DATA_VALID1;
+ err = ext4_split_extent_at(handle, inode, path,
+ map->m_lblk + map->m_len, split_flag1, flags1);
+ if (err)
+ goto out;
+ } else {
+ allocated = ee_len - (map->m_lblk - ee_block);
+ }
+
+ ext4_ext_drop_refs(path);
+ path = ext4_ext_find_extent(inode, map->m_lblk, path);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
+ if (map->m_lblk >= ee_block) {
+ split_flag1 = split_flag & (EXT4_EXT_MAY_ZEROOUT |
+ EXT4_EXT_DATA_VALID2);
+ if (uninitialized)
+ split_flag1 |= EXT4_EXT_MARK_UNINIT1;
+ if (split_flag & EXT4_EXT_MARK_UNINIT2)
+ split_flag1 |= EXT4_EXT_MARK_UNINIT2;
+ err = ext4_split_extent_at(handle, inode, path,
+ map->m_lblk, split_flag1, flags);
+ if (err)
+ goto out;
+ }
+
+ ext4_ext_show_leaf(inode, path);
+out:
+ return err ? err : allocated;
+}
+
+#define EXT4_EXT_ZERO_LEN 7
+/*
+ * This function is called by ext4_ext_map_blocks() if someone tries to write
+ * to an uninitialized extent. It may result in splitting the uninitialized
+ * extent into multiple extents (up to three - one initialized and two
+ * uninitialized).
+ * There are three possibilities:
+ * a> There is no split required: Entire extent should be initialized
+ * b> Splits in two extents: Write is happening at either end of the extent
+ * c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * Pre-conditions:
+ * - The extent pointed to by 'path' is uninitialized.
+ * - The extent pointed to by 'path' contains a superset
+ * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
+ *
+ * Post-conditions on success:
+ * - the returned value is the number of blocks beyond map->l_lblk
+ * that are allocated and initialized.
+ * It is guaranteed to be >= map->m_len.
+ */
+static int ext4_ext_convert_to_initialized(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent_header *eh;
+ struct ext4_map_blocks split_map;
+ struct ext4_extent zero_ex;
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block, eof_block;
+ unsigned int ee_len, depth;
+ int allocated;
+ int err = 0;
+ int split_flag = 0;
+
+ ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
+ "block %llu, max_blocks %u\n", inode->i_ino,
+ (unsigned long long)map->m_lblk, map->m_len);
+
+ eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
+ inode->i_sb->s_blocksize_bits;
+ if (eof_block < map->m_lblk + map->m_len)
+ eof_block = map->m_lblk + map->m_len;
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ allocated = ee_len - (map->m_lblk - ee_block);
+
+ trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
+
+ /* Pre-conditions */
+ BUG_ON(!ext4_ext_is_uninitialized(ex));
+ BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
+
+ /*
+ * Attempt to transfer newly initialized blocks from the currently
+ * uninitialized extent to its left neighbor. This is much cheaper
+ * than an insertion followed by a merge as those involve costly
+ * memmove() calls. This is the common case in steady state for
+ * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append
+ * writes.
+ *
+ * Limitations of the current logic:
+ * - L1: we only deal with writes at the start of the extent.
+ * The approach could be extended to writes at the end
+ * of the extent but this scenario was deemed less common.
+ * - L2: we do not deal with writes covering the whole extent.
+ * This would require removing the extent if the transfer
+ * is possible.
+ * - L3: we only attempt to merge with an extent stored in the
+ * same extent tree node.
+ */
+ if ((map->m_lblk == ee_block) && /*L1*/
+ (map->m_len < ee_len) && /*L2*/
+ (ex > EXT_FIRST_EXTENT(eh))) { /*L3*/
+ struct ext4_extent *prev_ex;
+ ext4_lblk_t prev_lblk;
+ ext4_fsblk_t prev_pblk, ee_pblk;
+ unsigned int prev_len, write_len;
+
+ prev_ex = ex - 1;
+ prev_lblk = le32_to_cpu(prev_ex->ee_block);
+ prev_len = ext4_ext_get_actual_len(prev_ex);
+ prev_pblk = ext4_ext_pblock(prev_ex);
+ ee_pblk = ext4_ext_pblock(ex);
+ write_len = map->m_len;
+
+ /*
+ * A transfer of blocks from 'ex' to 'prev_ex' is allowed
+ * upon those conditions:
+ * - C1: prev_ex is initialized,
+ * - C2: prev_ex is logically abutting ex,
+ * - C3: prev_ex is physically abutting ex,
+ * - C4: prev_ex can receive the additional blocks without
+ * overflowing the (initialized) length limit.
+ */
+ if ((!ext4_ext_is_uninitialized(prev_ex)) && /*C1*/
+ ((prev_lblk + prev_len) == ee_block) && /*C2*/
+ ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
+ (prev_len < (EXT_INIT_MAX_LEN - write_len))) { /*C4*/
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ trace_ext4_ext_convert_to_initialized_fastpath(inode,
+ map, ex, prev_ex);
+
+ /* Shift the start of ex by 'write_len' blocks */
+ ex->ee_block = cpu_to_le32(ee_block + write_len);
+ ext4_ext_store_pblock(ex, ee_pblk + write_len);
+ ex->ee_len = cpu_to_le16(ee_len - write_len);
+ ext4_ext_mark_uninitialized(ex); /* Restore the flag */
+
+ /* Extend prev_ex by 'write_len' blocks */
+ prev_ex->ee_len = cpu_to_le16(prev_len + write_len);
+
+ /* Mark the block containing both extents as dirty */
+ ext4_ext_dirty(handle, inode, path + depth);
+
+ /* Update path to point to the right extent */
+ path[depth].p_ext = prev_ex;
+
+ /* Result: number of initialized blocks past m_lblk */
+ allocated = write_len;
+ goto out;
+ }
+ }
+
+ WARN_ON(map->m_lblk < ee_block);
+ /*
+ * It is safe to convert extent to initialized via explicit
+ * zeroout only if extent is fully insde i_size or new_size.
+ */
+ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
+
+ /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
+ if (ee_len <= 2*EXT4_EXT_ZERO_LEN &&
+ (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ err = ext4_ext_zeroout(inode, ex);
+ if (err)
+ goto out;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+ ext4_ext_mark_initialized(ex);
+ ext4_ext_try_to_merge(inode, path, ex);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ goto out;
+ }
+
+ /*
+ * four cases:
+ * 1. split the extent into three extents.
+ * 2. split the extent into two extents, zeroout the first half.
+ * 3. split the extent into two extents, zeroout the second half.
+ * 4. split the extent into two extents with out zeroout.
+ */
+ split_map.m_lblk = map->m_lblk;
+ split_map.m_len = map->m_len;
+
+ if (allocated > map->m_len) {
+ if (allocated <= EXT4_EXT_ZERO_LEN &&
+ (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ /* case 3 */
+ zero_ex.ee_block =
+ cpu_to_le32(map->m_lblk);
+ zero_ex.ee_len = cpu_to_le16(allocated);
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex) + map->m_lblk - ee_block);
+ err = ext4_ext_zeroout(inode, &zero_ex);
+ if (err)
+ goto out;
+ split_map.m_lblk = map->m_lblk;
+ split_map.m_len = allocated;
+ } else if ((map->m_lblk - ee_block + map->m_len <
+ EXT4_EXT_ZERO_LEN) &&
+ (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
+ /* case 2 */
+ if (map->m_lblk != ee_block) {
+ zero_ex.ee_block = ex->ee_block;
+ zero_ex.ee_len = cpu_to_le16(map->m_lblk -
+ ee_block);
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex));
+ err = ext4_ext_zeroout(inode, &zero_ex);
+ if (err)
+ goto out;
+ }
+
+ split_map.m_lblk = ee_block;
+ split_map.m_len = map->m_lblk - ee_block + map->m_len;
+ allocated = map->m_len;
+ }
+ }
+
+ allocated = ext4_split_extent(handle, inode, path,
+ &split_map, split_flag, 0);
+ if (allocated < 0)
+ err = allocated;
+
+out:
+ return err ? err : allocated;
+}
+
+/*
+ * This function is called by ext4_ext_map_blocks() from
+ * ext4_get_blocks_dio_write() when DIO to write
+ * to an uninitialized extent.
+ *
+ * Writing to an uninitialized extent may result in splitting the uninitialized
+ * extent into multiple /initialized uninitialized extents (up to three)
+ * There are three possibilities:
+ * a> There is no split required: Entire extent should be uninitialized
+ * b> Splits in two extents: Write is happening at either end of the extent
+ * c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * One of more index blocks maybe needed if the extent tree grow after
+ * the uninitialized extent split. To prevent ENOSPC occur at the IO
+ * complete, we need to split the uninitialized extent before DIO submit
+ * the IO. The uninitialized extent called at this time will be split
+ * into three uninitialized extent(at most). After IO complete, the part
+ * being filled will be convert to initialized by the end_io callback function
+ * via ext4_convert_unwritten_extents().
+ *
+ * Returns the size of uninitialized extent to be written on success.
+ */
+static int ext4_split_unwritten_extents(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path,
+ int flags)
+{
+ ext4_lblk_t eof_block;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len;
+ int split_flag = 0, depth;
+
+ ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
+ "block %llu, max_blocks %u\n", inode->i_ino,
+ (unsigned long long)map->m_lblk, map->m_len);
+
+ eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
+ inode->i_sb->s_blocksize_bits;
+ if (eof_block < map->m_lblk + map->m_len)
+ eof_block = map->m_lblk + map->m_len;
+ /*
+ * It is safe to convert extent to initialized via explicit
+ * zeroout only if extent is fully insde i_size or new_size.
+ */
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
+ split_flag |= EXT4_EXT_MARK_UNINIT2;
+ if (flags & EXT4_GET_BLOCKS_CONVERT)
+ split_flag |= EXT4_EXT_DATA_VALID2;
+ flags |= EXT4_GET_BLOCKS_PRE_IO;
+ return ext4_split_extent(handle, inode, path, map, split_flag, flags);
+}
+
+static int ext4_convert_unwritten_extents_endio(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+ unsigned int ee_len;
+ int depth;
+ int err = 0;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
+ "block %llu, max_blocks %u\n", inode->i_ino,
+ (unsigned long long)ee_block, ee_len);
+
+ /* If extent is larger than requested then split is required */
+ if (ee_block != map->m_lblk || ee_len > map->m_len) {
+ err = ext4_split_unwritten_extents(handle, inode, map, path,
+ EXT4_GET_BLOCKS_CONVERT);
+ if (err < 0)
+ goto out;
+ ext4_ext_drop_refs(path);
+ path = ext4_ext_find_extent(inode, map->m_lblk, path);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+ /* first mark the extent as initialized */
+ ext4_ext_mark_initialized(ex);
+
+ /* note: ext4_ext_correct_indexes() isn't needed here because
+ * borders are not changed
+ */
+ ext4_ext_try_to_merge(inode, path, ex);
+
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+out:
+ ext4_ext_show_leaf(inode, path);
+ return err;
+}
+
+static void unmap_underlying_metadata_blocks(struct block_device *bdev,
+ sector_t block, int count)
+{
+ int i;
+ for (i = 0; i < count; i++)
+ unmap_underlying_metadata(bdev, block + i);
+}
+
+/*
+ * Handle EOFBLOCKS_FL flag, clearing it if necessary
+ */
+static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
+ ext4_lblk_t lblk,
+ struct ext4_ext_path *path,
+ unsigned int len)
+{
+ int i, depth;
+ struct ext4_extent_header *eh;
+ struct ext4_extent *last_ex;
+
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
+ return 0;
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+
+ /*
+ * We're going to remove EOFBLOCKS_FL entirely in future so we
+ * do not care for this case anymore. Simply remove the flag
+ * if there are no extents.
+ */
+ if (unlikely(!eh->eh_entries))
+ goto out;
+ last_ex = EXT_LAST_EXTENT(eh);
+ /*
+ * We should clear the EOFBLOCKS_FL flag if we are writing the
+ * last block in the last extent in the file. We test this by
+ * first checking to see if the caller to
+ * ext4_ext_get_blocks() was interested in the last block (or
+ * a block beyond the last block) in the current extent. If
+ * this turns out to be false, we can bail out from this
+ * function immediately.
+ */
+ if (lblk + len < le32_to_cpu(last_ex->ee_block) +
+ ext4_ext_get_actual_len(last_ex))
+ return 0;
+ /*
+ * If the caller does appear to be planning to write at or
+ * beyond the end of the current extent, we then test to see
+ * if the current extent is the last extent in the file, by
+ * checking to make sure it was reached via the rightmost node
+ * at each level of the tree.
+ */
+ for (i = depth-1; i >= 0; i--)
+ if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
+ return 0;
+out:
+ ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
+ return ext4_mark_inode_dirty(handle, inode);
+}
+
+/**
+ * ext4_find_delalloc_range: find delayed allocated block in the given range.
+ *
+ * Goes through the buffer heads in the range [lblk_start, lblk_end] and returns
+ * whether there are any buffers marked for delayed allocation. It returns '1'
+ * on the first delalloc'ed buffer head found. If no buffer head in the given
+ * range is marked for delalloc, it returns 0.
+ * lblk_start should always be <= lblk_end.
+ * search_hint_reverse is to indicate that searching in reverse from lblk_end to
+ * lblk_start might be more efficient (i.e., we will likely hit the delalloc'ed
+ * block sooner). This is useful when blocks are truncated sequentially from
+ * lblk_start towards lblk_end.
+ */
+static int ext4_find_delalloc_range(struct inode *inode,
+ ext4_lblk_t lblk_start,
+ ext4_lblk_t lblk_end,
+ int search_hint_reverse)
+{
+ struct address_space *mapping = inode->i_mapping;
+ struct buffer_head *head, *bh = NULL;
+ struct page *page;
+ ext4_lblk_t i, pg_lblk;
+ pgoff_t index;
+
+ if (!test_opt(inode->i_sb, DELALLOC))
+ return 0;
+
+ /* reverse search wont work if fs block size is less than page size */
+ if (inode->i_blkbits < PAGE_CACHE_SHIFT)
+ search_hint_reverse = 0;
+
+ if (search_hint_reverse)
+ i = lblk_end;
+ else
+ i = lblk_start;
+
+ index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+ while ((i >= lblk_start) && (i <= lblk_end)) {
+ page = find_get_page(mapping, index);
+ if (!page)
+ goto nextpage;
+
+ if (!page_has_buffers(page))
+ goto nextpage;
+
+ head = page_buffers(page);
+ if (!head)
+ goto nextpage;
+
+ bh = head;
+ pg_lblk = index << (PAGE_CACHE_SHIFT -
+ inode->i_blkbits);
+ do {
+ if (unlikely(pg_lblk < lblk_start)) {
+ /*
+ * This is possible when fs block size is less
+ * than page size and our cluster starts/ends in
+ * middle of the page. So we need to skip the
+ * initial few blocks till we reach the 'lblk'
+ */
+ pg_lblk++;
+ continue;
+ }
+
+ /* Check if the buffer is delayed allocated and that it
+ * is not yet mapped. (when da-buffers are mapped during
+ * their writeout, their da_mapped bit is set.)
+ */
+ if (buffer_delay(bh) && !buffer_da_mapped(bh)) {
+ page_cache_release(page);
+ trace_ext4_find_delalloc_range(inode,
+ lblk_start, lblk_end,
+ search_hint_reverse,
+ 1, i);
+ return 1;
+ }
+ if (search_hint_reverse)
+ i--;
+ else
+ i++;
+ } while ((i >= lblk_start) && (i <= lblk_end) &&
+ ((bh = bh->b_this_page) != head));
+nextpage:
+ if (page)
+ page_cache_release(page);
+ /*
+ * Move to next page. 'i' will be the first lblk in the next
+ * page.
+ */
+ if (search_hint_reverse)
+ index--;
+ else
+ index++;
+ i = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ }
+
+ trace_ext4_find_delalloc_range(inode, lblk_start, lblk_end,
+ search_hint_reverse, 0, 0);
+ return 0;
+}
+
+int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk,
+ int search_hint_reverse)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t lblk_start, lblk_end;
+ lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
+ lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
+
+ return ext4_find_delalloc_range(inode, lblk_start, lblk_end,
+ search_hint_reverse);
+}
+
+/**
+ * Determines how many complete clusters (out of those specified by the 'map')
+ * are under delalloc and were reserved quota for.
+ * This function is called when we are writing out the blocks that were
+ * originally written with their allocation delayed, but then the space was
+ * allocated using fallocate() before the delayed allocation could be resolved.
+ * The cases to look for are:
+ * ('=' indicated delayed allocated blocks
+ * '-' indicates non-delayed allocated blocks)
+ * (a) partial clusters towards beginning and/or end outside of allocated range
+ * are not delalloc'ed.
+ * Ex:
+ * |----c---=|====c====|====c====|===-c----|
+ * |++++++ allocated ++++++|
+ * ==> 4 complete clusters in above example
+ *
+ * (b) partial cluster (outside of allocated range) towards either end is
+ * marked for delayed allocation. In this case, we will exclude that
+ * cluster.
+ * Ex:
+ * |----====c========|========c========|
+ * |++++++ allocated ++++++|
+ * ==> 1 complete clusters in above example
+ *
+ * Ex:
+ * |================c================|
+ * |++++++ allocated ++++++|
+ * ==> 0 complete clusters in above example
+ *
+ * The ext4_da_update_reserve_space will be called only if we
+ * determine here that there were some "entire" clusters that span
+ * this 'allocated' range.
+ * In the non-bigalloc case, this function will just end up returning num_blks
+ * without ever calling ext4_find_delalloc_range.
+ */
+static unsigned int
+get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
+ unsigned int num_blks)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
+ ext4_lblk_t lblk_from, lblk_to, c_offset;
+ unsigned int allocated_clusters = 0;
+
+ alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
+ alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
+
+ /* max possible clusters for this allocation */
+ allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
+
+ trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
+
+ /* Check towards left side */
+ c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
+ if (c_offset) {
+ lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
+ lblk_to = lblk_from + c_offset - 1;
+
+ if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0))
+ allocated_clusters--;
+ }
+
+ /* Now check towards right. */
+ c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
+ if (allocated_clusters && c_offset) {
+ lblk_from = lblk_start + num_blks;
+ lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
+
+ if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0))
+ allocated_clusters--;
+ }
+
+ return allocated_clusters;
+}
+
+static int
+ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path, int flags,
+ unsigned int allocated, ext4_fsblk_t newblock)
+{
+ int ret = 0;
+ int err = 0;
+ ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+
+ ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
+ "block %llu, max_blocks %u, flags %x, allocated %u\n",
+ inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
+ flags, allocated);
+ ext4_ext_show_leaf(inode, path);
+
+ trace_ext4_ext_handle_uninitialized_extents(inode, map, allocated,
+ newblock);
+
+ /* get_block() before submit the IO, split the extent */
+ if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
+ ret = ext4_split_unwritten_extents(handle, inode, map,
+ path, flags);
+ /*
+ * Flag the inode(non aio case) or end_io struct (aio case)
+ * that this IO needs to conversion to written when IO is
+ * completed
+ */
+ if (io)
+ ext4_set_io_unwritten_flag(inode, io);
+ else
+ ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
+ if (ext4_should_dioread_nolock(inode))
+ map->m_flags |= EXT4_MAP_UNINIT;
+ goto out;
+ }
+ /* IO end_io complete, convert the filled extent to written */
+ if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
+ ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
+ path);
+ if (ret >= 0) {
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ err = check_eofblocks_fl(handle, inode, map->m_lblk,
+ path, map->m_len);
+ } else
+ err = ret;
+ goto out2;
+ }
+ /* buffered IO case */
+ /*
+ * repeat fallocate creation request
+ * we already have an unwritten extent
+ */
+ if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
+ goto map_out;
+
+ /* buffered READ or buffered write_begin() lookup */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * We have blocks reserved already. We
+ * return allocated blocks so that delalloc
+ * won't do block reservation for us. But
+ * the buffer head will be unmapped so that
+ * a read from the block returns 0s.
+ */
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto out1;
+ }
+
+ /* buffered write, writepage time, convert*/
+ ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+out:
+ if (ret <= 0) {
+ err = ret;
+ goto out2;
+ } else
+ allocated = ret;
+ map->m_flags |= EXT4_MAP_NEW;
+ /*
+ * if we allocated more blocks than requested
+ * we need to make sure we unmap the extra block
+ * allocated. The actual needed block will get
+ * unmapped later when we find the buffer_head marked
+ * new.
+ */
+ if (allocated > map->m_len) {
+ unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
+ newblock + map->m_len,
+ allocated - map->m_len);
+ allocated = map->m_len;
+ }
+ map->m_len = allocated;
+
+ /*
+ * If we have done fallocate with the offset that is already
+ * delayed allocated, we would have block reservation
+ * and quota reservation done in the delayed write path.
+ * But fallocate would have already updated quota and block
+ * count for this offset. So cancel these reservation
+ */
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
+ unsigned int reserved_clusters;
+ reserved_clusters = get_reserved_cluster_alloc(inode,
+ map->m_lblk, map->m_len);
+ if (reserved_clusters)
+ ext4_da_update_reserve_space(inode,
+ reserved_clusters,
+ 0);
+ }
+
+map_out:
+ map->m_flags |= EXT4_MAP_MAPPED;
+ if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
+ err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
+ map->m_len);
+ if (err < 0)
+ goto out2;
+ }
+out1:
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ ext4_ext_show_leaf(inode, path);
+ map->m_pblk = newblock;
+ map->m_len = allocated;
+out2:
+ if (path) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+ return err ? err : allocated;
+}
+
+/*
+ * get_implied_cluster_alloc - check to see if the requested
+ * allocation (in the map structure) overlaps with a cluster already
+ * allocated in an extent.
+ * @sb The filesystem superblock structure
+ * @map The requested lblk->pblk mapping
+ * @ex The extent structure which might contain an implied
+ * cluster allocation
+ *
+ * This function is called by ext4_ext_map_blocks() after we failed to
+ * find blocks that were already in the inode's extent tree. Hence,
+ * we know that the beginning of the requested region cannot overlap
+ * the extent from the inode's extent tree. There are three cases we
+ * want to catch. The first is this case:
+ *
+ * |--- cluster # N--|
+ * |--- extent ---| |---- requested region ---|
+ * |==========|
+ *
+ * The second case that we need to test for is this one:
+ *
+ * |--------- cluster # N ----------------|
+ * |--- requested region --| |------- extent ----|
+ * |=======================|
+ *
+ * The third case is when the requested region lies between two extents
+ * within the same cluster:
+ * |------------- cluster # N-------------|
+ * |----- ex -----| |---- ex_right ----|
+ * |------ requested region ------|
+ * |================|
+ *
+ * In each of the above cases, we need to set the map->m_pblk and
+ * map->m_len so it corresponds to the return the extent labelled as
+ * "|====|" from cluster #N, since it is already in use for data in
+ * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
+ * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
+ * as a new "allocated" block region. Otherwise, we will return 0 and
+ * ext4_ext_map_blocks() will then allocate one or more new clusters
+ * by calling ext4_mb_new_blocks().
+ */
+static int get_implied_cluster_alloc(struct super_block *sb,
+ struct ext4_map_blocks *map,
+ struct ext4_extent *ex,
+ struct ext4_ext_path *path)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
+ ext4_lblk_t ex_cluster_start, ex_cluster_end;
+ ext4_lblk_t rr_cluster_start;
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ unsigned short ee_len = ext4_ext_get_actual_len(ex);
+
+ /* The extent passed in that we are trying to match */
+ ex_cluster_start = EXT4_B2C(sbi, ee_block);
+ ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
+
+ /* The requested region passed into ext4_map_blocks() */
+ rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
+
+ if ((rr_cluster_start == ex_cluster_end) ||
+ (rr_cluster_start == ex_cluster_start)) {
+ if (rr_cluster_start == ex_cluster_end)
+ ee_start += ee_len - 1;
+ map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
+ c_offset;
+ map->m_len = min(map->m_len,
+ (unsigned) sbi->s_cluster_ratio - c_offset);
+ /*
+ * Check for and handle this case:
+ *
+ * |--------- cluster # N-------------|
+ * |------- extent ----|
+ * |--- requested region ---|
+ * |===========|
+ */
+
+ if (map->m_lblk < ee_block)
+ map->m_len = min(map->m_len, ee_block - map->m_lblk);
+
+ /*
+ * Check for the case where there is already another allocated
+ * block to the right of 'ex' but before the end of the cluster.
+ *
+ * |------------- cluster # N-------------|
+ * |----- ex -----| |---- ex_right ----|
+ * |------ requested region ------|
+ * |================|
+ */
+ if (map->m_lblk > ee_block) {
+ ext4_lblk_t next = ext4_ext_next_allocated_block(path);
+ map->m_len = min(map->m_len, next - map->m_lblk);
+ }
+
+ trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
+ return 1;
+ }
+
+ trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
+ return 0;
+}
+
+
+/*
+ * Block allocation/map/preallocation routine for extents based files
+ *
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ *
+ * return > 0, number of of blocks already mapped/allocated
+ * if create == 0 and these are pre-allocated blocks
+ * buffer head is unmapped
+ * otherwise blocks are mapped
+ *
+ * return = 0, if plain look up failed (blocks have not been allocated)
+ * buffer head is unmapped
+ *
+ * return < 0, error case.
+ */
+int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent newex, *ex, *ex2;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_fsblk_t newblock = 0;
+ int free_on_err = 0, err = 0, depth, ret;
+ unsigned int allocated = 0, offset = 0;
+ unsigned int allocated_clusters = 0;
+ struct ext4_allocation_request ar;
+ ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+ ext4_lblk_t cluster_offset;
+
+ ext_debug("blocks %u/%u requested for inode %lu\n",
+ map->m_lblk, map->m_len, inode->i_ino);
+ trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
+
+ /* check in cache */
+ if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
+ if (!newex.ee_start_lo && !newex.ee_start_hi) {
+ if ((sbi->s_cluster_ratio > 1) &&
+ ext4_find_delalloc_cluster(inode, map->m_lblk, 0))
+ map->m_flags |= EXT4_MAP_FROM_CLUSTER;
+
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * block isn't allocated yet and
+ * user doesn't want to allocate it
+ */
+ goto out2;
+ }
+ /* we should allocate requested block */
+ } else {
+ /* block is already allocated */
+ if (sbi->s_cluster_ratio > 1)
+ map->m_flags |= EXT4_MAP_FROM_CLUSTER;
+ newblock = map->m_lblk
+ - le32_to_cpu(newex.ee_block)
+ + ext4_ext_pblock(&newex);
+ /* number of remaining blocks in the extent */
+ allocated = ext4_ext_get_actual_len(&newex) -
+ (map->m_lblk - le32_to_cpu(newex.ee_block));
+ goto out;
+ }
+ }
+
+ /* find extent for this block */
+ path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ goto out2;
+ }
+
+ depth = ext_depth(inode);
+
+ /*
+ * consistent leaf must not be empty;
+ * this situation is possible, though, _during_ tree modification;
+ * this is why assert can't be put in ext4_ext_find_extent()
+ */
+ if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
+ EXT4_ERROR_INODE(inode, "bad extent address "
+ "lblock: %lu, depth: %d pblock %lld",
+ (unsigned long) map->m_lblk, depth,
+ path[depth].p_block);
+ err = -EIO;
+ goto out2;
+ }
+
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ unsigned short ee_len;
+
+ /*
+ * Uninitialized extents are treated as holes, except that
+ * we split out initialized portions during a write.
+ */
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
+
+ /* if found extent covers block, simply return it */
+ if (in_range(map->m_lblk, ee_block, ee_len)) {
+ newblock = map->m_lblk - ee_block + ee_start;
+ /* number of remaining blocks in the extent */
+ allocated = ee_len - (map->m_lblk - ee_block);
+ ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
+ ee_block, ee_len, newblock);
+
+ /*
+ * Do not put uninitialized extent
+ * in the cache
+ */
+ if (!ext4_ext_is_uninitialized(ex)) {
+ ext4_ext_put_in_cache(inode, ee_block,
+ ee_len, ee_start);
+ goto out;
+ }
+ ret = ext4_ext_handle_uninitialized_extents(
+ handle, inode, map, path, flags,
+ allocated, newblock);
+ return ret;
+ }
+ }
+
+ if ((sbi->s_cluster_ratio > 1) &&
+ ext4_find_delalloc_cluster(inode, map->m_lblk, 0))
+ map->m_flags |= EXT4_MAP_FROM_CLUSTER;
+
+ /*
+ * requested block isn't allocated yet;
+ * we couldn't try to create block if create flag is zero
+ */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * put just found gap into cache to speed up
+ * subsequent requests
+ */
+ ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
+ goto out2;
+ }
+
+ /*
+ * Okay, we need to do block allocation.
+ */
+ map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
+ newex.ee_block = cpu_to_le32(map->m_lblk);
+ cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
+
+ /*
+ * If we are doing bigalloc, check to see if the extent returned
+ * by ext4_ext_find_extent() implies a cluster we can use.
+ */
+ if (cluster_offset && ex &&
+ get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
+ ar.len = allocated = map->m_len;
+ newblock = map->m_pblk;
+ map->m_flags |= EXT4_MAP_FROM_CLUSTER;
+ goto got_allocated_blocks;
+ }
+
+ /* find neighbour allocated blocks */
+ ar.lleft = map->m_lblk;
+ err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
+ if (err)
+ goto out2;
+ ar.lright = map->m_lblk;
+ ex2 = NULL;
+ err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
+ if (err)
+ goto out2;
+
+ /* Check if the extent after searching to the right implies a
+ * cluster we can use. */
+ if ((sbi->s_cluster_ratio > 1) && ex2 &&
+ get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
+ ar.len = allocated = map->m_len;
+ newblock = map->m_pblk;
+ map->m_flags |= EXT4_MAP_FROM_CLUSTER;
+ goto got_allocated_blocks;
+ }
+
+ /*
+ * See if request is beyond maximum number of blocks we can have in
+ * a single extent. For an initialized extent this limit is
+ * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
+ * EXT_UNINIT_MAX_LEN.
+ */
+ if (map->m_len > EXT_INIT_MAX_LEN &&
+ !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
+ map->m_len = EXT_INIT_MAX_LEN;
+ else if (map->m_len > EXT_UNINIT_MAX_LEN &&
+ (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
+ map->m_len = EXT_UNINIT_MAX_LEN;
+
+ /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
+ newex.ee_len = cpu_to_le16(map->m_len);
+ err = ext4_ext_check_overlap(sbi, inode, &newex, path);
+ if (err)
+ allocated = ext4_ext_get_actual_len(&newex);
+ else
+ allocated = map->m_len;
+
+ /* allocate new block */
+ ar.inode = inode;
+ ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
+ ar.logical = map->m_lblk;
+ /*
+ * We calculate the offset from the beginning of the cluster
+ * for the logical block number, since when we allocate a
+ * physical cluster, the physical block should start at the
+ * same offset from the beginning of the cluster. This is
+ * needed so that future calls to get_implied_cluster_alloc()
+ * work correctly.
+ */
+ offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
+ ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
+ ar.goal -= offset;
+ ar.logical -= offset;
+ if (S_ISREG(inode->i_mode))
+ ar.flags = EXT4_MB_HINT_DATA;
+ else
+ /* disable in-core preallocation for non-regular files */
+ ar.flags = 0;
+ if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
+ ar.flags |= EXT4_MB_HINT_NOPREALLOC;
+ newblock = ext4_mb_new_blocks(handle, &ar, &err);
+ if (!newblock)
+ goto out2;
+ ext_debug("allocate new block: goal %llu, found %llu/%u\n",
+ ar.goal, newblock, allocated);
+ free_on_err = 1;
+ allocated_clusters = ar.len;
+ ar.len = EXT4_C2B(sbi, ar.len) - offset;
+ if (ar.len > allocated)
+ ar.len = allocated;
+
+got_allocated_blocks:
+ /* try to insert new extent into found leaf and return */
+ ext4_ext_store_pblock(&newex, newblock + offset);
+ newex.ee_len = cpu_to_le16(ar.len);
+ /* Mark uninitialized */
+ if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
+ ext4_ext_mark_uninitialized(&newex);
+ /*
+ * io_end structure was created for every IO write to an
+ * uninitialized extent. To avoid unnecessary conversion,
+ * here we flag the IO that really needs the conversion.
+ * For non asycn direct IO case, flag the inode state
+ * that we need to perform conversion when IO is done.
+ */
+ if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
+ if (io)
+ ext4_set_io_unwritten_flag(inode, io);
+ else
+ ext4_set_inode_state(inode,
+ EXT4_STATE_DIO_UNWRITTEN);
+ }
+ if (ext4_should_dioread_nolock(inode))
+ map->m_flags |= EXT4_MAP_UNINIT;
+ }
+
+ err = 0;
+ if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
+ err = check_eofblocks_fl(handle, inode, map->m_lblk,
+ path, ar.len);
+ if (!err)
+ err = ext4_ext_insert_extent(handle, inode, path,
+ &newex, flags);
+ if (err && free_on_err) {
+ int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
+ EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
+ /* free data blocks we just allocated */
+ /* not a good idea to call discard here directly,
+ * but otherwise we'd need to call it every free() */
+ ext4_discard_preallocations(inode);
+ ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
+ ext4_ext_get_actual_len(&newex), fb_flags);
+ goto out2;
+ }
+
+ /* previous routine could use block we allocated */
+ newblock = ext4_ext_pblock(&newex);
+ allocated = ext4_ext_get_actual_len(&newex);
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_flags |= EXT4_MAP_NEW;
+
+ /*
+ * Update reserved blocks/metadata blocks after successful
+ * block allocation which had been deferred till now.
+ */
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
+ unsigned int reserved_clusters;
+ /*
+ * Check how many clusters we had reserved this allocated range
+ */
+ reserved_clusters = get_reserved_cluster_alloc(inode,
+ map->m_lblk, allocated);
+ if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
+ if (reserved_clusters) {
+ /*
+ * We have clusters reserved for this range.
+ * But since we are not doing actual allocation
+ * and are simply using blocks from previously
+ * allocated cluster, we should release the
+ * reservation and not claim quota.
+ */
+ ext4_da_update_reserve_space(inode,
+ reserved_clusters, 0);
+ }
+ } else {
+ BUG_ON(allocated_clusters < reserved_clusters);
+ /* We will claim quota for all newly allocated blocks.*/
+ ext4_da_update_reserve_space(inode, allocated_clusters,
+ 1);
+ if (reserved_clusters < allocated_clusters) {
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int reservation = allocated_clusters -
+ reserved_clusters;
+ /*
+ * It seems we claimed few clusters outside of
+ * the range of this allocation. We should give
+ * it back to the reservation pool. This can
+ * happen in the following case:
+ *
+ * * Suppose s_cluster_ratio is 4 (i.e., each
+ * cluster has 4 blocks. Thus, the clusters
+ * are [0-3],[4-7],[8-11]...
+ * * First comes delayed allocation write for
+ * logical blocks 10 & 11. Since there were no
+ * previous delayed allocated blocks in the
+ * range [8-11], we would reserve 1 cluster
+ * for this write.
+ * * Next comes write for logical blocks 3 to 8.
+ * In this case, we will reserve 2 clusters
+ * (for [0-3] and [4-7]; and not for [8-11] as
+ * that range has a delayed allocated blocks.
+ * Thus total reserved clusters now becomes 3.
+ * * Now, during the delayed allocation writeout
+ * time, we will first write blocks [3-8] and
+ * allocate 3 clusters for writing these
+ * blocks. Also, we would claim all these
+ * three clusters above.
+ * * Now when we come here to writeout the
+ * blocks [10-11], we would expect to claim
+ * the reservation of 1 cluster we had made
+ * (and we would claim it since there are no
+ * more delayed allocated blocks in the range
+ * [8-11]. But our reserved cluster count had
+ * already gone to 0.
+ *
+ * Thus, at the step 4 above when we determine
+ * that there are still some unwritten delayed
+ * allocated blocks outside of our current
+ * block range, we should increment the
+ * reserved clusters count so that when the
+ * remaining blocks finally gets written, we
+ * could claim them.
+ */
+ dquot_reserve_block(inode,
+ EXT4_C2B(sbi, reservation));
+ spin_lock(&ei->i_block_reservation_lock);
+ ei->i_reserved_data_blocks += reservation;
+ spin_unlock(&ei->i_block_reservation_lock);
+ }
+ }
+ }
+
+ /*
+ * Cache the extent and update transaction to commit on fdatasync only
+ * when it is _not_ an uninitialized extent.
+ */
+ if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
+ ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ } else
+ ext4_update_inode_fsync_trans(handle, inode, 0);
+out:
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ ext4_ext_show_leaf(inode, path);
+ map->m_flags |= EXT4_MAP_MAPPED;
+ map->m_pblk = newblock;
+ map->m_len = allocated;
+out2:
+ if (path) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+
+ trace_ext4_ext_map_blocks_exit(inode, map->m_lblk,
+ newblock, map->m_len, err ? err : allocated);
+
+ return err ? err : allocated;
+}
+
+void ext4_ext_truncate(struct inode *inode)
+{
+ struct address_space *mapping = inode->i_mapping;
+ struct super_block *sb = inode->i_sb;
+ ext4_lblk_t last_block;
+ handle_t *handle;
+ loff_t page_len;
+ int err = 0;
+
+ /*
+ * finish any pending end_io work so we won't run the risk of
+ * converting any truncated blocks to initialized later
+ */
+ ext4_flush_completed_IO(inode);
+
+ /*
+ * probably first extent we're gonna free will be last in block
+ */
+ err = ext4_writepage_trans_blocks(inode);
+ handle = ext4_journal_start(inode, err);
+ if (IS_ERR(handle))
+ return;
+
+ if (inode->i_size % PAGE_CACHE_SIZE != 0) {
+ page_len = PAGE_CACHE_SIZE -
+ (inode->i_size & (PAGE_CACHE_SIZE - 1));
+
+ err = ext4_discard_partial_page_buffers(handle,
+ mapping, inode->i_size, page_len, 0);
+
+ if (err)
+ goto out_stop;
+ }
+
+ if (ext4_orphan_add(handle, inode))
+ goto out_stop;
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_ext_invalidate_cache(inode);
+
+ ext4_discard_preallocations(inode);
+
+ /*
+ * TODO: optimization is possible here.
+ * Probably we need not scan at all,
+ * because page truncation is enough.
+ */
+
+ /* we have to know where to truncate from in crash case */
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ ext4_mark_inode_dirty(handle, inode);
+
+ last_block = (inode->i_size + sb->s_blocksize - 1)
+ >> EXT4_BLOCK_SIZE_BITS(sb);
+ err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
+
+ /* In a multi-transaction truncate, we only make the final
+ * transaction synchronous.
+ */
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+
+ up_write(&EXT4_I(inode)->i_data_sem);
+
+out_stop:
+ /*
+ * If this was a simple ftruncate() and the file will remain alive,
+ * then we need to clear up the orphan record which we created above.
+ * However, if this was a real unlink then we were called by
+ * ext4_delete_inode(), and we allow that function to clean up the
+ * orphan info for us.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(handle, inode);
+
+ inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+}
+
+static void ext4_falloc_update_inode(struct inode *inode,
+ int mode, loff_t new_size, int update_ctime)
+{
+ struct timespec now;
+
+ if (update_ctime) {
+ now = current_fs_time(inode->i_sb);
+ if (!timespec_equal(&inode->i_ctime, &now))
+ inode->i_ctime = now;
+ }
+ /*
+ * Update only when preallocation was requested beyond
+ * the file size.
+ */
+ if (!(mode & FALLOC_FL_KEEP_SIZE)) {
+ if (new_size > i_size_read(inode))
+ i_size_write(inode, new_size);
+ if (new_size > EXT4_I(inode)->i_disksize)
+ ext4_update_i_disksize(inode, new_size);
+ } else {
+ /*
+ * Mark that we allocate beyond EOF so the subsequent truncate
+ * can proceed even if the new size is the same as i_size.
+ */
+ if (new_size > i_size_read(inode))
+ ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
+ }
+
+}
+
+/*
+ * preallocate space for a file. This implements ext4's fallocate file
+ * operation, which gets called from sys_fallocate system call.
+ * For block-mapped files, posix_fallocate should fall back to the method
+ * of writing zeroes to the required new blocks (the same behavior which is
+ * expected for file systems which do not support fallocate() system call).
+ */
+long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ handle_t *handle;
+ loff_t new_size;
+ unsigned int max_blocks;
+ int ret = 0;
+ int ret2 = 0;
+ int retries = 0;
+ int flags;
+ struct ext4_map_blocks map;
+ unsigned int credits, blkbits = inode->i_blkbits;
+
+ /* Return error if mode is not supported */
+ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+ return -EOPNOTSUPP;
+
+ if (mode & FALLOC_FL_PUNCH_HOLE)
+ return ext4_punch_hole(file, offset, len);
+
+ trace_ext4_fallocate_enter(inode, offset, len, mode);
+ map.m_lblk = offset >> blkbits;
+ /*
+ * We can't just convert len to max_blocks because
+ * If blocksize = 4096 offset = 3072 and len = 2048
+ */
+ max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
+ - map.m_lblk;
+ /*
+ * credits to insert 1 extent into extent tree
+ */
+ credits = ext4_chunk_trans_blocks(inode, max_blocks);
+ mutex_lock(&inode->i_mutex);
+
+ /*
+ * We only support preallocation for extent-based files only
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ mutex_unlock(&inode->i_mutex);
+ return -EOPNOTSUPP;
+ }
+
+ ret = inode_newsize_ok(inode, (len + offset));
+ if (ret) {
+ mutex_unlock(&inode->i_mutex);
+ trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
+ return ret;
+ }
+ flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
+ if (mode & FALLOC_FL_KEEP_SIZE)
+ flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
+ /*
+ * Don't normalize the request if it can fit in one extent so
+ * that it doesn't get unnecessarily split into multiple
+ * extents.
+ */
+ if (len <= EXT_UNINIT_MAX_LEN << blkbits)
+ flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
+retry:
+ while (ret >= 0 && ret < max_blocks) {
+ map.m_lblk = map.m_lblk + ret;
+ map.m_len = max_blocks = max_blocks - ret;
+ handle = ext4_journal_start(inode, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ break;
+ }
+ ret = ext4_map_blocks(handle, inode, &map, flags);
+ if (ret <= 0) {
+#ifdef EXT4FS_DEBUG
+ WARN_ON(ret <= 0);
+ printk(KERN_ERR "%s: ext4_ext_map_blocks "
+ "returned error inode#%lu, block=%u, "
+ "max_blocks=%u", __func__,
+ inode->i_ino, map.m_lblk, max_blocks);
+#endif
+ ext4_mark_inode_dirty(handle, inode);
+ ret2 = ext4_journal_stop(handle);
+ break;
+ }
+ if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
+ blkbits) >> blkbits))
+ new_size = offset + len;
+ else
+ new_size = ((loff_t) map.m_lblk + ret) << blkbits;
+
+ ext4_falloc_update_inode(inode, mode, new_size,
+ (map.m_flags & EXT4_MAP_NEW));
+ ext4_mark_inode_dirty(handle, inode);
+ ret2 = ext4_journal_stop(handle);
+ if (ret2)
+ break;
+ }
+ if (ret == -ENOSPC &&
+ ext4_should_retry_alloc(inode->i_sb, &retries)) {
+ ret = 0;
+ goto retry;
+ }
+ mutex_unlock(&inode->i_mutex);
+ trace_ext4_fallocate_exit(inode, offset, max_blocks,
+ ret > 0 ? ret2 : ret);
+ return ret > 0 ? ret2 : ret;
+}
+
+/*
+ * This function convert a range of blocks to written extents
+ * The caller of this function will pass the start offset and the size.
+ * all unwritten extents within this range will be converted to
+ * written extents.
+ *
+ * This function is called from the direct IO end io call back
+ * function, to convert the fallocated extents after IO is completed.
+ * Returns 0 on success.
+ */
+int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
+ ssize_t len)
+{
+ handle_t *handle;
+ unsigned int max_blocks;
+ int ret = 0;
+ int ret2 = 0;
+ struct ext4_map_blocks map;
+ unsigned int credits, blkbits = inode->i_blkbits;
+
+ map.m_lblk = offset >> blkbits;
+ /*
+ * We can't just convert len to max_blocks because
+ * If blocksize = 4096 offset = 3072 and len = 2048
+ */
+ max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
+ map.m_lblk);
+ /*
+ * credits to insert 1 extent into extent tree
+ */
+ credits = ext4_chunk_trans_blocks(inode, max_blocks);
+ while (ret >= 0 && ret < max_blocks) {
+ map.m_lblk += ret;
+ map.m_len = (max_blocks -= ret);
+ handle = ext4_journal_start(inode, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ break;
+ }
+ ret = ext4_map_blocks(handle, inode, &map,
+ EXT4_GET_BLOCKS_IO_CONVERT_EXT);
+ if (ret <= 0) {
+ WARN_ON(ret <= 0);
+ ext4_msg(inode->i_sb, KERN_ERR,
+ "%s:%d: inode #%lu: block %u: len %u: "
+ "ext4_ext_map_blocks returned %d",
+ __func__, __LINE__, inode->i_ino, map.m_lblk,
+ map.m_len, ret);
+ }
+ ext4_mark_inode_dirty(handle, inode);
+ ret2 = ext4_journal_stop(handle);
+ if (ret <= 0 || ret2 )
+ break;
+ }
+ return ret > 0 ? ret2 : ret;
+}
+
+/*
+ * Callback function called for each extent to gather FIEMAP information.
+ */
+static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next,
+ struct ext4_ext_cache *newex, struct ext4_extent *ex,
+ void *data)
+{
+ __u64 logical;
+ __u64 physical;
+ __u64 length;
+ __u32 flags = 0;
+ int ret = 0;
+ struct fiemap_extent_info *fieinfo = data;
+ unsigned char blksize_bits;
+
+ blksize_bits = inode->i_sb->s_blocksize_bits;
+ logical = (__u64)newex->ec_block << blksize_bits;
+
+ if (newex->ec_start == 0) {
+ /*
+ * No extent in extent-tree contains block @newex->ec_start,
+ * then the block may stay in 1)a hole or 2)delayed-extent.
+ *
+ * Holes or delayed-extents are processed as follows.
+ * 1. lookup dirty pages with specified range in pagecache.
+ * If no page is got, then there is no delayed-extent and
+ * return with EXT_CONTINUE.
+ * 2. find the 1st mapped buffer,
+ * 3. check if the mapped buffer is both in the request range
+ * and a delayed buffer. If not, there is no delayed-extent,
+ * then return.
+ * 4. a delayed-extent is found, the extent will be collected.
+ */
+ ext4_lblk_t end = 0;
+ pgoff_t last_offset;
+ pgoff_t offset;
+ pgoff_t index;
+ pgoff_t start_index = 0;
+ struct page **pages = NULL;
+ struct buffer_head *bh = NULL;
+ struct buffer_head *head = NULL;
+ unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *);
+
+ pages = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (pages == NULL)
+ return -ENOMEM;
+
+ offset = logical >> PAGE_SHIFT;
+repeat:
+ last_offset = offset;
+ head = NULL;
+ ret = find_get_pages_tag(inode->i_mapping, &offset,
+ PAGECACHE_TAG_DIRTY, nr_pages, pages);
+
+ if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
+ /* First time, try to find a mapped buffer. */
+ if (ret == 0) {
+out:
+ for (index = 0; index < ret; index++)
+ page_cache_release(pages[index]);
+ /* just a hole. */
+ kfree(pages);
+ return EXT_CONTINUE;
+ }
+ index = 0;
+
+next_page:
+ /* Try to find the 1st mapped buffer. */
+ end = ((__u64)pages[index]->index << PAGE_SHIFT) >>
+ blksize_bits;
+ if (!page_has_buffers(pages[index]))
+ goto out;
+ head = page_buffers(pages[index]);
+ if (!head)
+ goto out;
+
+ index++;
+ bh = head;
+ do {
+ if (end >= newex->ec_block +
+ newex->ec_len)
+ /* The buffer is out of
+ * the request range.
+ */
+ goto out;
+
+ if (buffer_mapped(bh) &&
+ end >= newex->ec_block) {
+ start_index = index - 1;
+ /* get the 1st mapped buffer. */
+ goto found_mapped_buffer;
+ }
+
+ bh = bh->b_this_page;
+ end++;
+ } while (bh != head);
+
+ /* No mapped buffer in the range found in this page,
+ * We need to look up next page.
+ */
+ if (index >= ret) {
+ /* There is no page left, but we need to limit
+ * newex->ec_len.
+ */
+ newex->ec_len = end - newex->ec_block;
+ goto out;
+ }
+ goto next_page;
+ } else {
+ /*Find contiguous delayed buffers. */
+ if (ret > 0 && pages[0]->index == last_offset)
+ head = page_buffers(pages[0]);
+ bh = head;
+ index = 1;
+ start_index = 0;
+ }
+
+found_mapped_buffer:
+ if (bh != NULL && buffer_delay(bh)) {
+ /* 1st or contiguous delayed buffer found. */
+ if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
+ /*
+ * 1st delayed buffer found, record
+ * the start of extent.
+ */
+ flags |= FIEMAP_EXTENT_DELALLOC;
+ newex->ec_block = end;
+ logical = (__u64)end << blksize_bits;
+ }
+ /* Find contiguous delayed buffers. */
+ do {
+ if (!buffer_delay(bh))
+ goto found_delayed_extent;
+ bh = bh->b_this_page;
+ end++;
+ } while (bh != head);
+
+ for (; index < ret; index++) {
+ if (!page_has_buffers(pages[index])) {
+ bh = NULL;
+ break;
+ }
+ head = page_buffers(pages[index]);
+ if (!head) {
+ bh = NULL;
+ break;
+ }
+
+ if (pages[index]->index !=
+ pages[start_index]->index + index
+ - start_index) {
+ /* Blocks are not contiguous. */
+ bh = NULL;
+ break;
+ }
+ bh = head;
+ do {
+ if (!buffer_delay(bh))
+ /* Delayed-extent ends. */
+ goto found_delayed_extent;
+ bh = bh->b_this_page;
+ end++;
+ } while (bh != head);
+ }
+ } else if (!(flags & FIEMAP_EXTENT_DELALLOC))
+ /* a hole found. */
+ goto out;
+
+found_delayed_extent:
+ newex->ec_len = min(end - newex->ec_block,
+ (ext4_lblk_t)EXT_INIT_MAX_LEN);
+ if (ret == nr_pages && bh != NULL &&
+ newex->ec_len < EXT_INIT_MAX_LEN &&
+ buffer_delay(bh)) {
+ /* Have not collected an extent and continue. */
+ for (index = 0; index < ret; index++)
+ page_cache_release(pages[index]);
+ goto repeat;
+ }
+
+ for (index = 0; index < ret; index++)
+ page_cache_release(pages[index]);
+ kfree(pages);
+ }
+
+ physical = (__u64)newex->ec_start << blksize_bits;
+ length = (__u64)newex->ec_len << blksize_bits;
+
+ if (ex && ext4_ext_is_uninitialized(ex))
+ flags |= FIEMAP_EXTENT_UNWRITTEN;
+
+ if (next == EXT_MAX_BLOCKS)
+ flags |= FIEMAP_EXTENT_LAST;
+
+ ret = fiemap_fill_next_extent(fieinfo, logical, physical,
+ length, flags);
+ if (ret < 0)
+ return ret;
+ if (ret == 1)
+ return EXT_BREAK;
+ return EXT_CONTINUE;
+}
+/* fiemap flags we can handle specified here */
+#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
+
+static int ext4_xattr_fiemap(struct inode *inode,
+ struct fiemap_extent_info *fieinfo)
+{
+ __u64 physical = 0;
+ __u64 length;
+ __u32 flags = FIEMAP_EXTENT_LAST;
+ int blockbits = inode->i_sb->s_blocksize_bits;
+ int error = 0;
+
+ /* in-inode? */
+ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+ struct ext4_iloc iloc;
+ int offset; /* offset of xattr in inode */
+
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ return error;
+ physical = (__u64)iloc.bh->b_blocknr << blockbits;
+ offset = EXT4_GOOD_OLD_INODE_SIZE +
+ EXT4_I(inode)->i_extra_isize;
+ physical += offset;
+ length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
+ flags |= FIEMAP_EXTENT_DATA_INLINE;
+ brelse(iloc.bh);
+ } else { /* external block */
+ physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
+ length = inode->i_sb->s_blocksize;
+ }
+
+ if (physical)
+ error = fiemap_fill_next_extent(fieinfo, 0, physical,
+ length, flags);
+ return (error < 0 ? error : 0);
+}
+
+/*
+ * ext4_ext_punch_hole
+ *
+ * Punches a hole of "length" bytes in a file starting
+ * at byte "offset"
+ *
+ * @inode: The inode of the file to punch a hole in
+ * @offset: The starting byte offset of the hole
+ * @length: The length of the hole
+ *
+ * Returns the number of blocks removed or negative on err
+ */
+int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct super_block *sb = inode->i_sb;
+ ext4_lblk_t first_block, stop_block;
+ struct address_space *mapping = inode->i_mapping;
+ handle_t *handle;
+ loff_t first_page, last_page, page_len;
+ loff_t first_page_offset, last_page_offset;
+ int credits, err = 0;
+
+ /* No need to punch hole beyond i_size */
+ if (offset >= inode->i_size)
+ return 0;
+
+ /*
+ * If the hole extends beyond i_size, set the hole
+ * to end after the page that contains i_size
+ */
+ if (offset + length > inode->i_size) {
+ length = inode->i_size +
+ PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
+ offset;
+ }
+
+ first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ last_page = (offset + length) >> PAGE_CACHE_SHIFT;
+
+ first_page_offset = first_page << PAGE_CACHE_SHIFT;
+ last_page_offset = last_page << PAGE_CACHE_SHIFT;
+
+ /*
+ * Write out all dirty pages to avoid race conditions
+ * Then release them.
+ */
+ if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
+ err = filemap_write_and_wait_range(mapping,
+ offset, offset + length - 1);
+
+ if (err)
+ return err;
+ }
+
+ /* Now release the pages */
+ if (last_page_offset > first_page_offset) {
+ truncate_inode_pages_range(mapping, first_page_offset,
+ last_page_offset-1);
+ }
+
+ /* finish any pending end_io work */
+ ext4_flush_completed_IO(inode);
+
+ credits = ext4_writepage_trans_blocks(inode);
+ handle = ext4_journal_start(inode, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ err = ext4_orphan_add(handle, inode);
+ if (err)
+ goto out;
+
+ /*
+ * Now we need to zero out the non-page-aligned data in the
+ * pages at the start and tail of the hole, and unmap the buffer
+ * heads for the block aligned regions of the page that were
+ * completely zeroed.
+ */
+ if (first_page > last_page) {
+ /*
+ * If the file space being truncated is contained within a page
+ * just zero out and unmap the middle of that page
+ */
+ err = ext4_discard_partial_page_buffers(handle,
+ mapping, offset, length, 0);
+
+ if (err)
+ goto out;
+ } else {
+ /*
+ * zero out and unmap the partial page that contains
+ * the start of the hole
+ */
+ page_len = first_page_offset - offset;
+ if (page_len > 0) {
+ err = ext4_discard_partial_page_buffers(handle, mapping,
+ offset, page_len, 0);
+ if (err)
+ goto out;
+ }
+
+ /*
+ * zero out and unmap the partial page that contains
+ * the end of the hole
+ */
+ page_len = offset + length - last_page_offset;
+ if (page_len > 0) {
+ err = ext4_discard_partial_page_buffers(handle, mapping,
+ last_page_offset, page_len, 0);
+ if (err)
+ goto out;
+ }
+ }
+
+ /*
+ * If i_size is contained in the last page, we need to
+ * unmap and zero the partial page after i_size
+ */
+ if (inode->i_size >> PAGE_CACHE_SHIFT == last_page &&
+ inode->i_size % PAGE_CACHE_SIZE != 0) {
+
+ page_len = PAGE_CACHE_SIZE -
+ (inode->i_size & (PAGE_CACHE_SIZE - 1));
+
+ if (page_len > 0) {
+ err = ext4_discard_partial_page_buffers(handle,
+ mapping, inode->i_size, page_len, 0);
+
+ if (err)
+ goto out;
+ }
+ }
+
+ first_block = (offset + sb->s_blocksize - 1) >>
+ EXT4_BLOCK_SIZE_BITS(sb);
+ stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
+
+ /* If there are no blocks to remove, return now */
+ if (first_block >= stop_block)
+ goto out;
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_ext_invalidate_cache(inode);
+ ext4_discard_preallocations(inode);
+
+ err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
+
+ ext4_ext_invalidate_cache(inode);
+ ext4_discard_preallocations(inode);
+
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+
+ up_write(&EXT4_I(inode)->i_data_sem);
+
+out:
+ ext4_orphan_del(handle, inode);
+ inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+ return err;
+}
+int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len)
+{
+ ext4_lblk_t start_blk;
+ int error = 0;
+
+ /* fallback to generic here if not in extents fmt */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+ return generic_block_fiemap(inode, fieinfo, start, len,
+ ext4_get_block);
+
+ if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
+ return -EBADR;
+
+ if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+ error = ext4_xattr_fiemap(inode, fieinfo);
+ } else {
+ ext4_lblk_t len_blks;
+ __u64 last_blk;
+
+ start_blk = start >> inode->i_sb->s_blocksize_bits;
+ last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
+ if (last_blk >= EXT_MAX_BLOCKS)
+ last_blk = EXT_MAX_BLOCKS-1;
+ len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
+
+ /*
+ * Walk the extent tree gathering extent information.
+ * ext4_ext_fiemap_cb will push extents back to user.
+ */
+ error = ext4_ext_walk_space(inode, start_blk, len_blks,
+ ext4_ext_fiemap_cb, fieinfo);
+ }
+
+ return error;
+}