[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/btrfs/file.c b/ap/os/linux/linux-3.4.x/fs/btrfs/file.c
new file mode 100644
index 0000000..53bf2d7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/btrfs/file.c
@@ -0,0 +1,1908 @@
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 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
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/falloc.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include <linux/slab.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+#include "tree-log.h"
+#include "locking.h"
+#include "compat.h"
+
+/*
+ * when auto defrag is enabled we
+ * queue up these defrag structs to remember which
+ * inodes need defragging passes
+ */
+struct inode_defrag {
+ struct rb_node rb_node;
+ /* objectid */
+ u64 ino;
+ /*
+ * transid where the defrag was added, we search for
+ * extents newer than this
+ */
+ u64 transid;
+
+ /* root objectid */
+ u64 root;
+
+ /* last offset we were able to defrag */
+ u64 last_offset;
+
+ /* if we've wrapped around back to zero once already */
+ int cycled;
+};
+
+/* pop a record for an inode into the defrag tree. The lock
+ * must be held already
+ *
+ * If you're inserting a record for an older transid than an
+ * existing record, the transid already in the tree is lowered
+ *
+ * If an existing record is found the defrag item you
+ * pass in is freed
+ */
+static void __btrfs_add_inode_defrag(struct inode *inode,
+ struct inode_defrag *defrag)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct inode_defrag *entry;
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+
+ p = &root->fs_info->defrag_inodes.rb_node;
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct inode_defrag, rb_node);
+
+ if (defrag->ino < entry->ino)
+ p = &parent->rb_left;
+ else if (defrag->ino > entry->ino)
+ p = &parent->rb_right;
+ else {
+ /* if we're reinserting an entry for
+ * an old defrag run, make sure to
+ * lower the transid of our existing record
+ */
+ if (defrag->transid < entry->transid)
+ entry->transid = defrag->transid;
+ if (defrag->last_offset > entry->last_offset)
+ entry->last_offset = defrag->last_offset;
+ goto exists;
+ }
+ }
+ BTRFS_I(inode)->in_defrag = 1;
+ rb_link_node(&defrag->rb_node, parent, p);
+ rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
+ return;
+
+exists:
+ kfree(defrag);
+ return;
+
+}
+
+/*
+ * insert a defrag record for this inode if auto defrag is
+ * enabled
+ */
+int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct inode_defrag *defrag;
+ u64 transid;
+
+ if (!btrfs_test_opt(root, AUTO_DEFRAG))
+ return 0;
+
+ if (btrfs_fs_closing(root->fs_info))
+ return 0;
+
+ if (BTRFS_I(inode)->in_defrag)
+ return 0;
+
+ if (trans)
+ transid = trans->transid;
+ else
+ transid = BTRFS_I(inode)->root->last_trans;
+
+ defrag = kzalloc(sizeof(*defrag), GFP_NOFS);
+ if (!defrag)
+ return -ENOMEM;
+
+ defrag->ino = btrfs_ino(inode);
+ defrag->transid = transid;
+ defrag->root = root->root_key.objectid;
+
+ spin_lock(&root->fs_info->defrag_inodes_lock);
+ if (!BTRFS_I(inode)->in_defrag)
+ __btrfs_add_inode_defrag(inode, defrag);
+ else
+ kfree(defrag);
+ spin_unlock(&root->fs_info->defrag_inodes_lock);
+ return 0;
+}
+
+/*
+ * must be called with the defrag_inodes lock held
+ */
+struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, u64 ino,
+ struct rb_node **next)
+{
+ struct inode_defrag *entry = NULL;
+ struct rb_node *p;
+ struct rb_node *parent = NULL;
+
+ p = info->defrag_inodes.rb_node;
+ while (p) {
+ parent = p;
+ entry = rb_entry(parent, struct inode_defrag, rb_node);
+
+ if (ino < entry->ino)
+ p = parent->rb_left;
+ else if (ino > entry->ino)
+ p = parent->rb_right;
+ else
+ return entry;
+ }
+
+ if (next) {
+ while (parent && ino > entry->ino) {
+ parent = rb_next(parent);
+ entry = rb_entry(parent, struct inode_defrag, rb_node);
+ }
+ *next = parent;
+ }
+ return NULL;
+}
+
+/*
+ * run through the list of inodes in the FS that need
+ * defragging
+ */
+int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
+{
+ struct inode_defrag *defrag;
+ struct btrfs_root *inode_root;
+ struct inode *inode;
+ struct rb_node *n;
+ struct btrfs_key key;
+ struct btrfs_ioctl_defrag_range_args range;
+ u64 first_ino = 0;
+ int num_defrag;
+ int defrag_batch = 1024;
+
+ memset(&range, 0, sizeof(range));
+ range.len = (u64)-1;
+
+ atomic_inc(&fs_info->defrag_running);
+ spin_lock(&fs_info->defrag_inodes_lock);
+ while(1) {
+ n = NULL;
+
+ /* find an inode to defrag */
+ defrag = btrfs_find_defrag_inode(fs_info, first_ino, &n);
+ if (!defrag) {
+ if (n)
+ defrag = rb_entry(n, struct inode_defrag, rb_node);
+ else if (first_ino) {
+ first_ino = 0;
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ /* remove it from the rbtree */
+ first_ino = defrag->ino + 1;
+ rb_erase(&defrag->rb_node, &fs_info->defrag_inodes);
+
+ if (btrfs_fs_closing(fs_info))
+ goto next_free;
+
+ spin_unlock(&fs_info->defrag_inodes_lock);
+
+ /* get the inode */
+ key.objectid = defrag->root;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ key.offset = (u64)-1;
+ inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(inode_root))
+ goto next;
+
+ key.objectid = defrag->ino;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
+ if (IS_ERR(inode))
+ goto next;
+
+ /* do a chunk of defrag */
+ BTRFS_I(inode)->in_defrag = 0;
+ range.start = defrag->last_offset;
+ num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
+ defrag_batch);
+ /*
+ * if we filled the whole defrag batch, there
+ * must be more work to do. Queue this defrag
+ * again
+ */
+ if (num_defrag == defrag_batch) {
+ defrag->last_offset = range.start;
+ __btrfs_add_inode_defrag(inode, defrag);
+ /*
+ * we don't want to kfree defrag, we added it back to
+ * the rbtree
+ */
+ defrag = NULL;
+ } else if (defrag->last_offset && !defrag->cycled) {
+ /*
+ * we didn't fill our defrag batch, but
+ * we didn't start at zero. Make sure we loop
+ * around to the start of the file.
+ */
+ defrag->last_offset = 0;
+ defrag->cycled = 1;
+ __btrfs_add_inode_defrag(inode, defrag);
+ defrag = NULL;
+ }
+
+ iput(inode);
+next:
+ spin_lock(&fs_info->defrag_inodes_lock);
+next_free:
+ kfree(defrag);
+ }
+ spin_unlock(&fs_info->defrag_inodes_lock);
+
+ atomic_dec(&fs_info->defrag_running);
+
+ /*
+ * during unmount, we use the transaction_wait queue to
+ * wait for the defragger to stop
+ */
+ wake_up(&fs_info->transaction_wait);
+ return 0;
+}
+
+/* simple helper to fault in pages and copy. This should go away
+ * and be replaced with calls into generic code.
+ */
+static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
+ size_t write_bytes,
+ struct page **prepared_pages,
+ struct iov_iter *i)
+{
+ size_t copied = 0;
+ size_t total_copied = 0;
+ int pg = 0;
+ int offset = pos & (PAGE_CACHE_SIZE - 1);
+
+ while (write_bytes > 0) {
+ size_t count = min_t(size_t,
+ PAGE_CACHE_SIZE - offset, write_bytes);
+ struct page *page = prepared_pages[pg];
+ /*
+ * Copy data from userspace to the current page
+ *
+ * Disable pagefault to avoid recursive lock since
+ * the pages are already locked
+ */
+ pagefault_disable();
+ copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
+ pagefault_enable();
+
+ /* Flush processor's dcache for this page */
+ flush_dcache_page(page);
+
+ /*
+ * if we get a partial write, we can end up with
+ * partially up to date pages. These add
+ * a lot of complexity, so make sure they don't
+ * happen by forcing this copy to be retried.
+ *
+ * The rest of the btrfs_file_write code will fall
+ * back to page at a time copies after we return 0.
+ */
+ if (!PageUptodate(page) && copied < count)
+ copied = 0;
+
+ iov_iter_advance(i, copied);
+ write_bytes -= copied;
+ total_copied += copied;
+
+ /* Return to btrfs_file_aio_write to fault page */
+ if (unlikely(copied == 0))
+ break;
+
+ if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
+ offset += copied;
+ } else {
+ pg++;
+ offset = 0;
+ }
+ }
+ return total_copied;
+}
+
+/*
+ * unlocks pages after btrfs_file_write is done with them
+ */
+void btrfs_drop_pages(struct page **pages, size_t num_pages)
+{
+ size_t i;
+ for (i = 0; i < num_pages; i++) {
+ /* page checked is some magic around finding pages that
+ * have been modified without going through btrfs_set_page_dirty
+ * clear it here
+ */
+ ClearPageChecked(pages[i]);
+ unlock_page(pages[i]);
+ mark_page_accessed(pages[i]);
+ page_cache_release(pages[i]);
+ }
+}
+
+/*
+ * after copy_from_user, pages need to be dirtied and we need to make
+ * sure holes are created between the current EOF and the start of
+ * any next extents (if required).
+ *
+ * this also makes the decision about creating an inline extent vs
+ * doing real data extents, marking pages dirty and delalloc as required.
+ */
+int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
+ struct page **pages, size_t num_pages,
+ loff_t pos, size_t write_bytes,
+ struct extent_state **cached)
+{
+ int err = 0;
+ int i;
+ u64 num_bytes;
+ u64 start_pos;
+ u64 end_of_last_block;
+ u64 end_pos = pos + write_bytes;
+ loff_t isize = i_size_read(inode);
+
+ start_pos = pos & ~((u64)root->sectorsize - 1);
+ num_bytes = (write_bytes + pos - start_pos +
+ root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+
+ end_of_last_block = start_pos + num_bytes - 1;
+ err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
+ cached);
+ if (err)
+ return err;
+
+ for (i = 0; i < num_pages; i++) {
+ struct page *p = pages[i];
+ SetPageUptodate(p);
+ ClearPageChecked(p);
+ set_page_dirty(p);
+ }
+
+ /*
+ * we've only changed i_size in ram, and we haven't updated
+ * the disk i_size. There is no need to log the inode
+ * at this time.
+ */
+ if (end_pos > isize)
+ i_size_write(inode, end_pos);
+ return 0;
+}
+
+/*
+ * this drops all the extents in the cache that intersect the range
+ * [start, end]. Existing extents are split as required.
+ */
+int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
+ int skip_pinned)
+{
+ struct extent_map *em;
+ struct extent_map *split = NULL;
+ struct extent_map *split2 = NULL;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ u64 len = end - start + 1;
+ int ret;
+ int testend = 1;
+ unsigned long flags;
+ int compressed = 0;
+
+ WARN_ON(end < start);
+ if (end == (u64)-1) {
+ len = (u64)-1;
+ testend = 0;
+ }
+ while (1) {
+ if (!split)
+ split = alloc_extent_map();
+ if (!split2)
+ split2 = alloc_extent_map();
+ BUG_ON(!split || !split2); /* -ENOMEM */
+
+ write_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (!em) {
+ write_unlock(&em_tree->lock);
+ break;
+ }
+ flags = em->flags;
+ if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
+ if (testend && em->start + em->len >= start + len) {
+ free_extent_map(em);
+ write_unlock(&em_tree->lock);
+ break;
+ }
+ start = em->start + em->len;
+ if (testend)
+ len = start + len - (em->start + em->len);
+ free_extent_map(em);
+ write_unlock(&em_tree->lock);
+ continue;
+ }
+ compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ clear_bit(EXTENT_FLAG_PINNED, &em->flags);
+ remove_extent_mapping(em_tree, em);
+
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ em->start < start) {
+ split->start = em->start;
+ split->len = start - em->start;
+ split->orig_start = em->orig_start;
+ split->block_start = em->block_start;
+
+ if (compressed)
+ split->block_len = em->block_len;
+ else
+ split->block_len = split->len;
+
+ split->bdev = em->bdev;
+ split->flags = flags;
+ split->compress_type = em->compress_type;
+ ret = add_extent_mapping(em_tree, split);
+ BUG_ON(ret); /* Logic error */
+ free_extent_map(split);
+ split = split2;
+ split2 = NULL;
+ }
+ if (em->block_start < EXTENT_MAP_LAST_BYTE &&
+ testend && em->start + em->len > start + len) {
+ u64 diff = start + len - em->start;
+
+ split->start = start + len;
+ split->len = em->start + em->len - (start + len);
+ split->bdev = em->bdev;
+ split->flags = flags;
+ split->compress_type = em->compress_type;
+
+ if (compressed) {
+ split->block_len = em->block_len;
+ split->block_start = em->block_start;
+ split->orig_start = em->orig_start;
+ } else {
+ split->block_len = split->len;
+ split->block_start = em->block_start + diff;
+ split->orig_start = split->start;
+ }
+
+ ret = add_extent_mapping(em_tree, split);
+ BUG_ON(ret); /* Logic error */
+ free_extent_map(split);
+ split = NULL;
+ }
+ write_unlock(&em_tree->lock);
+
+ /* once for us */
+ free_extent_map(em);
+ /* once for the tree*/
+ free_extent_map(em);
+ }
+ if (split)
+ free_extent_map(split);
+ if (split2)
+ free_extent_map(split2);
+ return 0;
+}
+
+/*
+ * this is very complex, but the basic idea is to drop all extents
+ * in the range start - end. hint_block is filled in with a block number
+ * that would be a good hint to the block allocator for this file.
+ *
+ * If an extent intersects the range but is not entirely inside the range
+ * it is either truncated or split. Anything entirely inside the range
+ * is deleted from the tree.
+ */
+int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode,
+ u64 start, u64 end, u64 *hint_byte, int drop_cache)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_key new_key;
+ u64 ino = btrfs_ino(inode);
+ u64 search_start = start;
+ u64 disk_bytenr = 0;
+ u64 num_bytes = 0;
+ u64 extent_offset = 0;
+ u64 extent_end = 0;
+ int del_nr = 0;
+ int del_slot = 0;
+ int extent_type;
+ int recow;
+ int ret;
+ int modify_tree = -1;
+
+ if (drop_cache)
+ btrfs_drop_extent_cache(inode, start, end - 1, 0);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ if (start >= BTRFS_I(inode)->disk_i_size)
+ modify_tree = 0;
+
+ while (1) {
+ recow = 0;
+ ret = btrfs_lookup_file_extent(trans, root, path, ino,
+ search_start, modify_tree);
+ if (ret < 0)
+ break;
+ if (ret > 0 && path->slots[0] > 0 && search_start == start) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
+ if (key.objectid == ino &&
+ key.type == BTRFS_EXTENT_DATA_KEY)
+ path->slots[0]--;
+ }
+ ret = 0;
+next_slot:
+ leaf = path->nodes[0];
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ BUG_ON(del_nr > 0);
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ leaf = path->nodes[0];
+ recow = 1;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid > ino ||
+ key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
+ break;
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ extent_type = btrfs_file_extent_type(leaf, fi);
+
+ if (extent_type == BTRFS_FILE_EXTENT_REG ||
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ extent_offset = btrfs_file_extent_offset(leaf, fi);
+ extent_end = key.offset +
+ btrfs_file_extent_num_bytes(leaf, fi);
+ } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ extent_end = key.offset +
+ btrfs_file_extent_inline_len(leaf, fi);
+ } else {
+ WARN_ON(1);
+ extent_end = search_start;
+ }
+
+ if (extent_end <= search_start) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+
+ search_start = max(key.offset, start);
+ if (recow || !modify_tree) {
+ modify_tree = -1;
+ btrfs_release_path(path);
+ continue;
+ }
+
+ /*
+ * | - range to drop - |
+ * | -------- extent -------- |
+ */
+ if (start > key.offset && end < extent_end) {
+ BUG_ON(del_nr > 0);
+ BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
+
+ memcpy(&new_key, &key, sizeof(new_key));
+ new_key.offset = start;
+ ret = btrfs_duplicate_item(trans, root, path,
+ &new_key);
+ if (ret == -EAGAIN) {
+ btrfs_release_path(path);
+ continue;
+ }
+ if (ret < 0)
+ break;
+
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ start - key.offset);
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ extent_offset += start - key.offset;
+ btrfs_set_file_extent_offset(leaf, fi, extent_offset);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_end - start);
+ btrfs_mark_buffer_dirty(leaf);
+
+ if (disk_bytenr > 0) {
+ ret = btrfs_inc_extent_ref(trans, root,
+ disk_bytenr, num_bytes, 0,
+ root->root_key.objectid,
+ new_key.objectid,
+ start - extent_offset, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ *hint_byte = disk_bytenr;
+ }
+ key.offset = start;
+ }
+ /*
+ * | ---- range to drop ----- |
+ * | -------- extent -------- |
+ */
+ if (start <= key.offset && end < extent_end) {
+ BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
+
+ memcpy(&new_key, &key, sizeof(new_key));
+ new_key.offset = end;
+ btrfs_set_item_key_safe(trans, root, path, &new_key);
+
+ extent_offset += end - key.offset;
+ btrfs_set_file_extent_offset(leaf, fi, extent_offset);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_end - end);
+ btrfs_mark_buffer_dirty(leaf);
+ if (disk_bytenr > 0) {
+ inode_sub_bytes(inode, end - key.offset);
+ *hint_byte = disk_bytenr;
+ }
+ break;
+ }
+
+ search_start = extent_end;
+ /*
+ * | ---- range to drop ----- |
+ * | -------- extent -------- |
+ */
+ if (start > key.offset && end >= extent_end) {
+ BUG_ON(del_nr > 0);
+ BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
+
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ start - key.offset);
+ btrfs_mark_buffer_dirty(leaf);
+ if (disk_bytenr > 0) {
+ inode_sub_bytes(inode, extent_end - start);
+ *hint_byte = disk_bytenr;
+ }
+ if (end == extent_end)
+ break;
+
+ path->slots[0]++;
+ goto next_slot;
+ }
+
+ /*
+ * | ---- range to drop ----- |
+ * | ------ extent ------ |
+ */
+ if (start <= key.offset && end >= extent_end) {
+ if (del_nr == 0) {
+ del_slot = path->slots[0];
+ del_nr = 1;
+ } else {
+ BUG_ON(del_slot + del_nr != path->slots[0]);
+ del_nr++;
+ }
+
+ if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ inode_sub_bytes(inode,
+ extent_end - key.offset);
+ extent_end = ALIGN(extent_end,
+ root->sectorsize);
+ } else if (disk_bytenr > 0) {
+ ret = btrfs_free_extent(trans, root,
+ disk_bytenr, num_bytes, 0,
+ root->root_key.objectid,
+ key.objectid, key.offset -
+ extent_offset, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ inode_sub_bytes(inode,
+ extent_end - key.offset);
+ *hint_byte = disk_bytenr;
+ }
+
+ if (end == extent_end)
+ break;
+
+ if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
+ path->slots[0]++;
+ goto next_slot;
+ }
+
+ ret = btrfs_del_items(trans, root, path, del_slot,
+ del_nr);
+ if (ret) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+
+ del_nr = 0;
+ del_slot = 0;
+
+ btrfs_release_path(path);
+ continue;
+ }
+
+ BUG_ON(1);
+ }
+
+ if (!ret && del_nr > 0) {
+ ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ }
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int extent_mergeable(struct extent_buffer *leaf, int slot,
+ u64 objectid, u64 bytenr, u64 orig_offset,
+ u64 *start, u64 *end)
+{
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 extent_end;
+
+ if (slot < 0 || slot >= btrfs_header_nritems(leaf))
+ return 0;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
+ return 0;
+
+ fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
+ btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
+ btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
+ btrfs_file_extent_compression(leaf, fi) ||
+ btrfs_file_extent_encryption(leaf, fi) ||
+ btrfs_file_extent_other_encoding(leaf, fi))
+ return 0;
+
+ extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+ if ((*start && *start != key.offset) || (*end && *end != extent_end))
+ return 0;
+
+ *start = key.offset;
+ *end = extent_end;
+ return 1;
+}
+
+/*
+ * Mark extent in the range start - end as written.
+ *
+ * This changes extent type from 'pre-allocated' to 'regular'. If only
+ * part of extent is marked as written, the extent will be split into
+ * two or three.
+ */
+int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 start, u64 end)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_buffer *leaf;
+ struct btrfs_path *path;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ struct btrfs_key new_key;
+ u64 bytenr;
+ u64 num_bytes;
+ u64 extent_end;
+ u64 orig_offset;
+ u64 other_start;
+ u64 other_end;
+ u64 split;
+ int del_nr = 0;
+ int del_slot = 0;
+ int recow;
+ int ret;
+ u64 ino = btrfs_ino(inode);
+
+ btrfs_drop_extent_cache(inode, start, end - 1, 0);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+again:
+ recow = 0;
+ split = start;
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = split;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+ if (ret > 0 && path->slots[0] > 0)
+ path->slots[0]--;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ BUG_ON(btrfs_file_extent_type(leaf, fi) !=
+ BTRFS_FILE_EXTENT_PREALLOC);
+ extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+ BUG_ON(key.offset > start || extent_end < end);
+
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
+ memcpy(&new_key, &key, sizeof(new_key));
+
+ if (start == key.offset && end < extent_end) {
+ other_start = 0;
+ other_end = start;
+ if (extent_mergeable(leaf, path->slots[0] - 1,
+ ino, bytenr, orig_offset,
+ &other_start, &other_end)) {
+ new_key.offset = end;
+ btrfs_set_item_key_safe(trans, root, path, &new_key);
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_end - end);
+ btrfs_set_file_extent_offset(leaf, fi,
+ end - orig_offset);
+ fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ end - other_start);
+ btrfs_mark_buffer_dirty(leaf);
+ goto out;
+ }
+ }
+
+ if (start > key.offset && end == extent_end) {
+ other_start = end;
+ other_end = 0;
+ if (extent_mergeable(leaf, path->slots[0] + 1,
+ ino, bytenr, orig_offset,
+ &other_start, &other_end)) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ start - key.offset);
+ path->slots[0]++;
+ new_key.offset = start;
+ btrfs_set_item_key_safe(trans, root, path, &new_key);
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ other_end - start);
+ btrfs_set_file_extent_offset(leaf, fi,
+ start - orig_offset);
+ btrfs_mark_buffer_dirty(leaf);
+ goto out;
+ }
+ }
+
+ while (start > key.offset || end < extent_end) {
+ if (key.offset == start)
+ split = end;
+
+ new_key.offset = split;
+ ret = btrfs_duplicate_item(trans, root, path, &new_key);
+ if (ret == -EAGAIN) {
+ btrfs_release_path(path);
+ goto again;
+ }
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ split - key.offset);
+
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_end - split);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
+ root->root_key.objectid,
+ ino, orig_offset, 0);
+ BUG_ON(ret); /* -ENOMEM */
+
+ if (split == start) {
+ key.offset = start;
+ } else {
+ BUG_ON(start != key.offset);
+ path->slots[0]--;
+ extent_end = end;
+ }
+ recow = 1;
+ }
+
+ other_start = end;
+ other_end = 0;
+ if (extent_mergeable(leaf, path->slots[0] + 1,
+ ino, bytenr, orig_offset,
+ &other_start, &other_end)) {
+ if (recow) {
+ btrfs_release_path(path);
+ goto again;
+ }
+ extent_end = other_end;
+ del_slot = path->slots[0] + 1;
+ del_nr++;
+ ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
+ 0, root->root_key.objectid,
+ ino, orig_offset, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ }
+ other_start = 0;
+ other_end = start;
+ if (extent_mergeable(leaf, path->slots[0] - 1,
+ ino, bytenr, orig_offset,
+ &other_start, &other_end)) {
+ if (recow) {
+ btrfs_release_path(path);
+ goto again;
+ }
+ key.offset = other_start;
+ del_slot = path->slots[0];
+ del_nr++;
+ ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
+ 0, root->root_key.objectid,
+ ino, orig_offset, 0);
+ BUG_ON(ret); /* -ENOMEM */
+ }
+ if (del_nr == 0) {
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_type(leaf, fi,
+ BTRFS_FILE_EXTENT_REG);
+ btrfs_mark_buffer_dirty(leaf);
+ } else {
+ fi = btrfs_item_ptr(leaf, del_slot - 1,
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_type(leaf, fi,
+ BTRFS_FILE_EXTENT_REG);
+ btrfs_set_file_extent_num_bytes(leaf, fi,
+ extent_end - key.offset);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, root, ret);
+ goto out;
+ }
+ }
+out:
+ btrfs_free_path(path);
+ return 0;
+}
+
+/*
+ * on error we return an unlocked page and the error value
+ * on success we return a locked page and 0
+ */
+static int prepare_uptodate_page(struct page *page, u64 pos,
+ bool force_uptodate)
+{
+ int ret = 0;
+
+ if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
+ !PageUptodate(page)) {
+ ret = btrfs_readpage(NULL, page);
+ if (ret)
+ return ret;
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ unlock_page(page);
+ return -EIO;
+ }
+ }
+ return 0;
+}
+
+/*
+ * this gets pages into the page cache and locks them down, it also properly
+ * waits for data=ordered extents to finish before allowing the pages to be
+ * modified.
+ */
+static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
+ struct page **pages, size_t num_pages,
+ loff_t pos, unsigned long first_index,
+ size_t write_bytes, bool force_uptodate)
+{
+ struct extent_state *cached_state = NULL;
+ int i;
+ unsigned long index = pos >> PAGE_CACHE_SHIFT;
+ struct inode *inode = fdentry(file)->d_inode;
+ gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
+ int err = 0;
+ int faili = 0;
+ u64 start_pos;
+ u64 last_pos;
+
+ start_pos = pos & ~((u64)root->sectorsize - 1);
+ last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
+
+again:
+ for (i = 0; i < num_pages; i++) {
+ pages[i] = find_or_create_page(inode->i_mapping, index + i,
+ mask | __GFP_WRITE);
+ if (!pages[i]) {
+ faili = i - 1;
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ if (i == 0)
+ err = prepare_uptodate_page(pages[i], pos,
+ force_uptodate);
+ if (i == num_pages - 1)
+ err = prepare_uptodate_page(pages[i],
+ pos + write_bytes, false);
+ if (err) {
+ page_cache_release(pages[i]);
+ faili = i - 1;
+ goto fail;
+ }
+ wait_on_page_writeback(pages[i]);
+ }
+ err = 0;
+ if (start_pos < inode->i_size) {
+ struct btrfs_ordered_extent *ordered;
+ lock_extent_bits(&BTRFS_I(inode)->io_tree,
+ start_pos, last_pos - 1, 0, &cached_state);
+ ordered = btrfs_lookup_first_ordered_extent(inode,
+ last_pos - 1);
+ if (ordered &&
+ ordered->file_offset + ordered->len > start_pos &&
+ ordered->file_offset < last_pos) {
+ btrfs_put_ordered_extent(ordered);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree,
+ start_pos, last_pos - 1,
+ &cached_state, GFP_NOFS);
+ for (i = 0; i < num_pages; i++) {
+ unlock_page(pages[i]);
+ page_cache_release(pages[i]);
+ }
+ btrfs_wait_ordered_range(inode, start_pos,
+ last_pos - start_pos);
+ goto again;
+ }
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
+ last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
+ GFP_NOFS);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree,
+ start_pos, last_pos - 1, &cached_state,
+ GFP_NOFS);
+ }
+ for (i = 0; i < num_pages; i++) {
+ if (clear_page_dirty_for_io(pages[i]))
+ account_page_redirty(pages[i]);
+ set_page_extent_mapped(pages[i]);
+ WARN_ON(!PageLocked(pages[i]));
+ }
+ return 0;
+fail:
+ while (faili >= 0) {
+ unlock_page(pages[faili]);
+ page_cache_release(pages[faili]);
+ faili--;
+ }
+ return err;
+
+}
+
+static noinline ssize_t __btrfs_buffered_write(struct file *file,
+ struct iov_iter *i,
+ loff_t pos)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct page **pages = NULL;
+ unsigned long first_index;
+ size_t num_written = 0;
+ int nrptrs;
+ int ret = 0;
+ bool force_page_uptodate = false;
+
+ nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
+ PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
+ (sizeof(struct page *)));
+ nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
+ nrptrs = max(nrptrs, 8);
+ pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ return -ENOMEM;
+
+ first_index = pos >> PAGE_CACHE_SHIFT;
+
+ while (iov_iter_count(i) > 0) {
+ size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+ size_t write_bytes = min(iov_iter_count(i),
+ nrptrs * (size_t)PAGE_CACHE_SIZE -
+ offset);
+ size_t num_pages = (write_bytes + offset +
+ PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ size_t dirty_pages;
+ size_t copied;
+
+ WARN_ON(num_pages > nrptrs);
+
+ /*
+ * Fault pages before locking them in prepare_pages
+ * to avoid recursive lock
+ */
+ if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ ret = btrfs_delalloc_reserve_space(inode,
+ num_pages << PAGE_CACHE_SHIFT);
+ if (ret)
+ break;
+
+ /*
+ * This is going to setup the pages array with the number of
+ * pages we want, so we don't really need to worry about the
+ * contents of pages from loop to loop
+ */
+ ret = prepare_pages(root, file, pages, num_pages,
+ pos, first_index, write_bytes,
+ force_page_uptodate);
+ if (ret) {
+ btrfs_delalloc_release_space(inode,
+ num_pages << PAGE_CACHE_SHIFT);
+ break;
+ }
+
+ copied = btrfs_copy_from_user(pos, num_pages,
+ write_bytes, pages, i);
+
+ /*
+ * if we have trouble faulting in the pages, fall
+ * back to one page at a time
+ */
+ if (copied < write_bytes)
+ nrptrs = 1;
+
+ if (copied == 0) {
+ force_page_uptodate = true;
+ dirty_pages = 0;
+ } else {
+ force_page_uptodate = false;
+ dirty_pages = (copied + offset +
+ PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+ }
+
+ /*
+ * If we had a short copy we need to release the excess delaloc
+ * bytes we reserved. We need to increment outstanding_extents
+ * because btrfs_delalloc_release_space will decrement it, but
+ * we still have an outstanding extent for the chunk we actually
+ * managed to copy.
+ */
+ if (num_pages > dirty_pages) {
+ if (copied > 0) {
+ spin_lock(&BTRFS_I(inode)->lock);
+ BTRFS_I(inode)->outstanding_extents++;
+ spin_unlock(&BTRFS_I(inode)->lock);
+ }
+ btrfs_delalloc_release_space(inode,
+ (num_pages - dirty_pages) <<
+ PAGE_CACHE_SHIFT);
+ }
+
+ if (copied > 0) {
+ ret = btrfs_dirty_pages(root, inode, pages,
+ dirty_pages, pos, copied,
+ NULL);
+ if (ret) {
+ btrfs_delalloc_release_space(inode,
+ dirty_pages << PAGE_CACHE_SHIFT);
+ btrfs_drop_pages(pages, num_pages);
+ break;
+ }
+ }
+
+ btrfs_drop_pages(pages, num_pages);
+
+ cond_resched();
+
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping,
+ dirty_pages);
+ if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
+ btrfs_btree_balance_dirty(root, 1);
+
+ pos += copied;
+ num_written += copied;
+ }
+
+ kfree(pages);
+
+ return num_written ? num_written : ret;
+}
+
+static ssize_t __btrfs_direct_write(struct kiocb *iocb,
+ const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos,
+ loff_t *ppos, size_t count, size_t ocount)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = fdentry(file)->d_inode;
+ struct iov_iter i;
+ ssize_t written;
+ ssize_t written_buffered;
+ loff_t endbyte;
+ int err;
+
+ written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
+ count, ocount);
+
+ /*
+ * the generic O_DIRECT will update in-memory i_size after the
+ * DIOs are done. But our endio handlers that update the on
+ * disk i_size never update past the in memory i_size. So we
+ * need one more update here to catch any additions to the
+ * file
+ */
+ if (inode->i_size != BTRFS_I(inode)->disk_i_size) {
+ btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
+ mark_inode_dirty(inode);
+ }
+
+ if (written < 0 || written == count)
+ return written;
+
+ pos += written;
+ count -= written;
+ iov_iter_init(&i, iov, nr_segs, count, written);
+ written_buffered = __btrfs_buffered_write(file, &i, pos);
+ if (written_buffered < 0) {
+ err = written_buffered;
+ goto out;
+ }
+ endbyte = pos + written_buffered - 1;
+ err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
+ if (err)
+ goto out;
+ written += written_buffered;
+ *ppos = pos + written_buffered;
+ invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+out:
+ return written ? written : err;
+}
+
+static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
+ const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ loff_t *ppos = &iocb->ki_pos;
+ u64 start_pos;
+ ssize_t num_written = 0;
+ ssize_t err = 0;
+ size_t count, ocount;
+
+ vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+
+ mutex_lock(&inode->i_mutex);
+
+ err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
+ if (err) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+ count = ocount;
+
+ current->backing_dev_info = inode->i_mapping->backing_dev_info;
+ err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+ if (err) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ if (count == 0) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ err = file_remove_suid(file);
+ if (err) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ /*
+ * If BTRFS flips readonly due to some impossible error
+ * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
+ * although we have opened a file as writable, we have
+ * to stop this write operation to ensure FS consistency.
+ */
+ if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+ mutex_unlock(&inode->i_mutex);
+ err = -EROFS;
+ goto out;
+ }
+
+ err = btrfs_update_time(file);
+ if (err) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+ BTRFS_I(inode)->sequence++;
+
+ start_pos = round_down(pos, root->sectorsize);
+ if (start_pos > i_size_read(inode)) {
+ err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
+ if (err) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+ }
+
+ if (unlikely(file->f_flags & O_DIRECT)) {
+ num_written = __btrfs_direct_write(iocb, iov, nr_segs,
+ pos, ppos, count, ocount);
+ } else {
+ struct iov_iter i;
+
+ iov_iter_init(&i, iov, nr_segs, count, num_written);
+
+ num_written = __btrfs_buffered_write(file, &i, pos);
+ if (num_written > 0)
+ *ppos = pos + num_written;
+ }
+
+ mutex_unlock(&inode->i_mutex);
+
+ /*
+ * we want to make sure fsync finds this change
+ * but we haven't joined a transaction running right now.
+ *
+ * Later on, someone is sure to update the inode and get the
+ * real transid recorded.
+ *
+ * We set last_trans now to the fs_info generation + 1,
+ * this will either be one more than the running transaction
+ * or the generation used for the next transaction if there isn't
+ * one running right now.
+ */
+ BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
+ if (num_written > 0 || num_written == -EIOCBQUEUED) {
+ err = generic_write_sync(file, pos, num_written);
+ if (err < 0 && num_written > 0)
+ num_written = err;
+ }
+out:
+ current->backing_dev_info = NULL;
+ return num_written ? num_written : err;
+}
+
+int btrfs_release_file(struct inode *inode, struct file *filp)
+{
+ /*
+ * ordered_data_close is set by settattr when we are about to truncate
+ * a file from a non-zero size to a zero size. This tries to
+ * flush down new bytes that may have been written if the
+ * application were using truncate to replace a file in place.
+ */
+ if (BTRFS_I(inode)->ordered_data_close) {
+ BTRFS_I(inode)->ordered_data_close = 0;
+ btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
+ if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
+ filemap_flush(inode->i_mapping);
+ }
+ if (filp->private_data)
+ btrfs_ioctl_trans_end(filp);
+ return 0;
+}
+
+/*
+ * fsync call for both files and directories. This logs the inode into
+ * the tree log instead of forcing full commits whenever possible.
+ *
+ * It needs to call filemap_fdatawait so that all ordered extent updates are
+ * in the metadata btree are up to date for copying to the log.
+ *
+ * It drops the inode mutex before doing the tree log commit. This is an
+ * important optimization for directories because holding the mutex prevents
+ * new operations on the dir while we write to disk.
+ */
+int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ struct btrfs_trans_handle *trans;
+
+ trace_btrfs_sync_file(file, datasync);
+
+ ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (ret)
+ return ret;
+ mutex_lock(&inode->i_mutex);
+
+ /* we wait first, since the writeback may change the inode */
+ root->log_batch++;
+ btrfs_wait_ordered_range(inode, 0, (u64)-1);
+ root->log_batch++;
+
+ /*
+ * check the transaction that last modified this inode
+ * and see if its already been committed
+ */
+ if (!BTRFS_I(inode)->last_trans) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ /*
+ * if the last transaction that changed this file was before
+ * the current transaction, we can bail out now without any
+ * syncing
+ */
+ smp_mb();
+ if (BTRFS_I(inode)->last_trans <=
+ root->fs_info->last_trans_committed) {
+ BTRFS_I(inode)->last_trans = 0;
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ /*
+ * ok we haven't committed the transaction yet, lets do a commit
+ */
+ if (file->private_data)
+ btrfs_ioctl_trans_end(file);
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ ret = btrfs_log_dentry_safe(trans, root, dentry);
+ if (ret < 0) {
+ mutex_unlock(&inode->i_mutex);
+ goto out;
+ }
+
+ /* we've logged all the items and now have a consistent
+ * version of the file in the log. It is possible that
+ * someone will come in and modify the file, but that's
+ * fine because the log is consistent on disk, and we
+ * have references to all of the file's extents
+ *
+ * It is possible that someone will come in and log the
+ * file again, but that will end up using the synchronization
+ * inside btrfs_sync_log to keep things safe.
+ */
+ mutex_unlock(&inode->i_mutex);
+
+ if (ret != BTRFS_NO_LOG_SYNC) {
+ if (ret > 0) {
+ ret = btrfs_commit_transaction(trans, root);
+ } else {
+ ret = btrfs_sync_log(trans, root);
+ if (ret == 0)
+ ret = btrfs_end_transaction(trans, root);
+ else
+ ret = btrfs_commit_transaction(trans, root);
+ }
+ } else {
+ ret = btrfs_end_transaction(trans, root);
+ }
+out:
+ return ret > 0 ? -EIO : ret;
+}
+
+static const struct vm_operations_struct btrfs_file_vm_ops = {
+ .fault = filemap_fault,
+ .page_mkwrite = btrfs_page_mkwrite,
+};
+
+static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct address_space *mapping = filp->f_mapping;
+
+ if (!mapping->a_ops->readpage)
+ return -ENOEXEC;
+
+ file_accessed(filp);
+ vma->vm_ops = &btrfs_file_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
+
+ return 0;
+}
+
+static long btrfs_fallocate(struct file *file, int mode,
+ loff_t offset, loff_t len)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct extent_state *cached_state = NULL;
+ u64 cur_offset;
+ u64 last_byte;
+ u64 alloc_start;
+ u64 alloc_end;
+ u64 alloc_hint = 0;
+ u64 locked_end;
+ u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
+ struct extent_map *em;
+ int ret;
+
+ alloc_start = offset & ~mask;
+ alloc_end = (offset + len + mask) & ~mask;
+
+ /* We only support the FALLOC_FL_KEEP_SIZE mode */
+ if (mode & ~FALLOC_FL_KEEP_SIZE)
+ return -EOPNOTSUPP;
+
+ /*
+ * Make sure we have enough space before we do the
+ * allocation.
+ */
+ ret = btrfs_check_data_free_space(inode, len);
+ if (ret)
+ return ret;
+
+ /*
+ * wait for ordered IO before we have any locks. We'll loop again
+ * below with the locks held.
+ */
+ btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);
+
+ mutex_lock(&inode->i_mutex);
+ ret = inode_newsize_ok(inode, alloc_end);
+ if (ret)
+ goto out;
+
+ if (alloc_start > inode->i_size) {
+ ret = btrfs_cont_expand(inode, i_size_read(inode),
+ alloc_start);
+ if (ret)
+ goto out;
+ }
+
+ locked_end = alloc_end - 1;
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+
+ /* the extent lock is ordered inside the running
+ * transaction
+ */
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
+ locked_end, 0, &cached_state);
+ ordered = btrfs_lookup_first_ordered_extent(inode,
+ alloc_end - 1);
+ if (ordered &&
+ ordered->file_offset + ordered->len > alloc_start &&
+ ordered->file_offset < alloc_end) {
+ btrfs_put_ordered_extent(ordered);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree,
+ alloc_start, locked_end,
+ &cached_state, GFP_NOFS);
+ /*
+ * we can't wait on the range with the transaction
+ * running or with the extent lock held
+ */
+ btrfs_wait_ordered_range(inode, alloc_start,
+ alloc_end - alloc_start);
+ } else {
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ }
+
+ cur_offset = alloc_start;
+ while (1) {
+ u64 actual_end;
+
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ alloc_end - cur_offset, 0);
+ if (IS_ERR_OR_NULL(em)) {
+ if (!em)
+ ret = -ENOMEM;
+ else
+ ret = PTR_ERR(em);
+ break;
+ }
+ last_byte = min(extent_map_end(em), alloc_end);
+ actual_end = min_t(u64, extent_map_end(em), offset + len);
+ last_byte = (last_byte + mask) & ~mask;
+
+ if (em->block_start == EXTENT_MAP_HOLE ||
+ (cur_offset >= inode->i_size &&
+ !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
+ ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
+ last_byte - cur_offset,
+ 1 << inode->i_blkbits,
+ offset + len,
+ &alloc_hint);
+
+ if (ret < 0) {
+ free_extent_map(em);
+ break;
+ }
+ } else if (actual_end > inode->i_size &&
+ !(mode & FALLOC_FL_KEEP_SIZE)) {
+ /*
+ * We didn't need to allocate any more space, but we
+ * still extended the size of the file so we need to
+ * update i_size.
+ */
+ inode->i_ctime = CURRENT_TIME;
+ i_size_write(inode, actual_end);
+ btrfs_ordered_update_i_size(inode, actual_end, NULL);
+ }
+ free_extent_map(em);
+
+ cur_offset = last_byte;
+ if (cur_offset >= alloc_end) {
+ ret = 0;
+ break;
+ }
+ }
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
+ &cached_state, GFP_NOFS);
+out:
+ mutex_unlock(&inode->i_mutex);
+ /* Let go of our reservation. */
+ btrfs_free_reserved_data_space(inode, len);
+ return ret;
+}
+
+static int find_desired_extent(struct inode *inode, loff_t *offset, int origin)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map *em;
+ struct extent_state *cached_state = NULL;
+ u64 lockstart = *offset;
+ u64 lockend = i_size_read(inode);
+ u64 start = *offset;
+ u64 orig_start = *offset;
+ u64 len = i_size_read(inode);
+ u64 last_end = 0;
+ int ret = 0;
+
+ lockend = max_t(u64, root->sectorsize, lockend);
+ if (lockend <= lockstart)
+ lockend = lockstart + root->sectorsize;
+
+ len = lockend - lockstart + 1;
+
+ len = max_t(u64, len, root->sectorsize);
+ if (inode->i_size == 0)
+ return -ENXIO;
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
+ &cached_state);
+
+ /*
+ * Delalloc is such a pain. If we have a hole and we have pending
+ * delalloc for a portion of the hole we will get back a hole that
+ * exists for the entire range since it hasn't been actually written
+ * yet. So to take care of this case we need to look for an extent just
+ * before the position we want in case there is outstanding delalloc
+ * going on here.
+ */
+ if (origin == SEEK_HOLE && start != 0) {
+ if (start <= root->sectorsize)
+ em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
+ root->sectorsize, 0);
+ else
+ em = btrfs_get_extent_fiemap(inode, NULL, 0,
+ start - root->sectorsize,
+ root->sectorsize, 0);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto out;
+ }
+ last_end = em->start + em->len;
+ if (em->block_start == EXTENT_MAP_DELALLOC)
+ last_end = min_t(u64, last_end, inode->i_size);
+ free_extent_map(em);
+ }
+
+ while (1) {
+ em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ break;
+ }
+
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ if (last_end <= orig_start) {
+ free_extent_map(em);
+ ret = -ENXIO;
+ break;
+ }
+ }
+
+ if (origin == SEEK_HOLE) {
+ *offset = start;
+ free_extent_map(em);
+ break;
+ }
+ } else {
+ if (origin == SEEK_DATA) {
+ if (em->block_start == EXTENT_MAP_DELALLOC) {
+ if (start >= inode->i_size) {
+ free_extent_map(em);
+ ret = -ENXIO;
+ break;
+ }
+ }
+
+ *offset = start;
+ free_extent_map(em);
+ break;
+ }
+ }
+
+ start = em->start + em->len;
+ last_end = em->start + em->len;
+
+ if (em->block_start == EXTENT_MAP_DELALLOC)
+ last_end = min_t(u64, last_end, inode->i_size);
+
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ free_extent_map(em);
+ ret = -ENXIO;
+ break;
+ }
+ free_extent_map(em);
+ cond_resched();
+ }
+ if (!ret)
+ *offset = min(*offset, inode->i_size);
+out:
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ &cached_state, GFP_NOFS);
+ return ret;
+}
+
+static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
+{
+ struct inode *inode = file->f_mapping->host;
+ int ret;
+
+ mutex_lock(&inode->i_mutex);
+ switch (origin) {
+ case SEEK_END:
+ case SEEK_CUR:
+ offset = generic_file_llseek(file, offset, origin);
+ goto out;
+ case SEEK_DATA:
+ case SEEK_HOLE:
+ if (offset >= i_size_read(inode)) {
+ mutex_unlock(&inode->i_mutex);
+ return -ENXIO;
+ }
+
+ ret = find_desired_extent(inode, &offset, origin);
+ if (ret) {
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+ }
+ }
+
+ if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
+ offset = -EINVAL;
+ goto out;
+ }
+ if (offset > inode->i_sb->s_maxbytes) {
+ offset = -EINVAL;
+ goto out;
+ }
+
+ /* Special lock needed here? */
+ if (offset != file->f_pos) {
+ file->f_pos = offset;
+ file->f_version = 0;
+ }
+out:
+ mutex_unlock(&inode->i_mutex);
+ return offset;
+}
+
+const struct file_operations btrfs_file_operations = {
+ .llseek = btrfs_file_llseek,
+ .read = do_sync_read,
+ .write = do_sync_write,
+ .aio_read = generic_file_aio_read,
+ .splice_read = generic_file_splice_read,
+ .aio_write = btrfs_file_aio_write,
+ .mmap = btrfs_file_mmap,
+ .open = generic_file_open,
+ .release = btrfs_release_file,
+ .fsync = btrfs_sync_file,
+ .fallocate = btrfs_fallocate,
+ .unlocked_ioctl = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = btrfs_ioctl,
+#endif
+};