[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/gfs2/dir.c b/src/kernel/linux/v4.14/fs/gfs2/dir.c
new file mode 100644
index 0000000..06a0d19
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/gfs2/dir.c
@@ -0,0 +1,2197 @@
+/*
+ * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+/*
+ * Implements Extendible Hashing as described in:
+ * "Extendible Hashing" by Fagin, et al in
+ * __ACM Trans. on Database Systems__, Sept 1979.
+ *
+ *
+ * Here's the layout of dirents which is essentially the same as that of ext2
+ * within a single block. The field de_name_len is the number of bytes
+ * actually required for the name (no null terminator). The field de_rec_len
+ * is the number of bytes allocated to the dirent. The offset of the next
+ * dirent in the block is (dirent + dirent->de_rec_len). When a dirent is
+ * deleted, the preceding dirent inherits its allocated space, ie
+ * prev->de_rec_len += deleted->de_rec_len. Since the next dirent is obtained
+ * by adding de_rec_len to the current dirent, this essentially causes the
+ * deleted dirent to get jumped over when iterating through all the dirents.
+ *
+ * When deleting the first dirent in a block, there is no previous dirent so
+ * the field de_ino is set to zero to designate it as deleted. When allocating
+ * a dirent, gfs2_dirent_alloc iterates through the dirents in a block. If the
+ * first dirent has (de_ino == 0) and de_rec_len is large enough, this first
+ * dirent is allocated. Otherwise it must go through all the 'used' dirents
+ * searching for one in which the amount of total space minus the amount of
+ * used space will provide enough space for the new dirent.
+ *
+ * There are two types of blocks in which dirents reside. In a stuffed dinode,
+ * the dirents begin at offset sizeof(struct gfs2_dinode) from the beginning of
+ * the block. In leaves, they begin at offset sizeof(struct gfs2_leaf) from the
+ * beginning of the leaf block. The dirents reside in leaves when
+ *
+ * dip->i_diskflags & GFS2_DIF_EXHASH is true
+ *
+ * Otherwise, the dirents are "linear", within a single stuffed dinode block.
+ *
+ * When the dirents are in leaves, the actual contents of the directory file are
+ * used as an array of 64-bit block pointers pointing to the leaf blocks. The
+ * dirents are NOT in the directory file itself. There can be more than one
+ * block pointer in the array that points to the same leaf. In fact, when a
+ * directory is first converted from linear to exhash, all of the pointers
+ * point to the same leaf.
+ *
+ * When a leaf is completely full, the size of the hash table can be
+ * doubled unless it is already at the maximum size which is hard coded into
+ * GFS2_DIR_MAX_DEPTH. After that, leaves are chained together in a linked list,
+ * but never before the maximum hash table size has been reached.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/buffer_head.h>
+#include <linux/sort.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/crc32.h>
+#include <linux/vmalloc.h>
+#include <linux/bio.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "dir.h"
+#include "glock.h"
+#include "inode.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "bmap.h"
+#include "util.h"
+
+#define IS_LEAF 1 /* Hashed (leaf) directory */
+#define IS_DINODE 2 /* Linear (stuffed dinode block) directory */
+
+#define MAX_RA_BLOCKS 32 /* max read-ahead blocks */
+
+#define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1)
+#define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1))
+#define GFS2_HASH_INDEX_MASK 0xffffc000
+#define GFS2_USE_HASH_FLAG 0x2000
+
+struct qstr gfs2_qdot __read_mostly;
+struct qstr gfs2_qdotdot __read_mostly;
+
+typedef int (*gfs2_dscan_t)(const struct gfs2_dirent *dent,
+ const struct qstr *name, void *opaque);
+
+int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
+ struct buffer_head **bhp)
+{
+ struct buffer_head *bh;
+
+ bh = gfs2_meta_new(ip->i_gl, block);
+ gfs2_trans_add_meta(ip->i_gl, bh);
+ gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
+ gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
+ *bhp = bh;
+ return 0;
+}
+
+static int gfs2_dir_get_existing_buffer(struct gfs2_inode *ip, u64 block,
+ struct buffer_head **bhp)
+{
+ struct buffer_head *bh;
+ int error;
+
+ error = gfs2_meta_read(ip->i_gl, block, DIO_WAIT, 0, &bh);
+ if (error)
+ return error;
+ if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_JD)) {
+ brelse(bh);
+ return -EIO;
+ }
+ *bhp = bh;
+ return 0;
+}
+
+static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
+ unsigned int offset, unsigned int size)
+{
+ struct buffer_head *dibh;
+ int error;
+
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (error)
+ return error;
+
+ gfs2_trans_add_meta(ip->i_gl, dibh);
+ memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
+ if (ip->i_inode.i_size < offset + size)
+ i_size_write(&ip->i_inode, offset + size);
+ ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+ gfs2_dinode_out(ip, dibh->b_data);
+
+ brelse(dibh);
+
+ return size;
+}
+
+
+
+/**
+ * gfs2_dir_write_data - Write directory information to the inode
+ * @ip: The GFS2 inode
+ * @buf: The buffer containing information to be written
+ * @offset: The file offset to start writing at
+ * @size: The amount of data to write
+ *
+ * Returns: The number of bytes correctly written or error code
+ */
+static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
+ u64 offset, unsigned int size)
+{
+ struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+ struct buffer_head *dibh;
+ u64 lblock, dblock;
+ u32 extlen = 0;
+ unsigned int o;
+ int copied = 0;
+ int error = 0;
+ int new = 0;
+
+ if (!size)
+ return 0;
+
+ if (gfs2_is_stuffed(ip) &&
+ offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
+ return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
+ size);
+
+ if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
+ return -EINVAL;
+
+ if (gfs2_is_stuffed(ip)) {
+ error = gfs2_unstuff_dinode(ip, NULL);
+ if (error)
+ return error;
+ }
+
+ lblock = offset;
+ o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
+
+ while (copied < size) {
+ unsigned int amount;
+ struct buffer_head *bh;
+
+ amount = size - copied;
+ if (amount > sdp->sd_sb.sb_bsize - o)
+ amount = sdp->sd_sb.sb_bsize - o;
+
+ if (!extlen) {
+ new = 1;
+ error = gfs2_extent_map(&ip->i_inode, lblock, &new,
+ &dblock, &extlen);
+ if (error)
+ goto fail;
+ error = -EIO;
+ if (gfs2_assert_withdraw(sdp, dblock))
+ goto fail;
+ }
+
+ if (amount == sdp->sd_jbsize || new)
+ error = gfs2_dir_get_new_buffer(ip, dblock, &bh);
+ else
+ error = gfs2_dir_get_existing_buffer(ip, dblock, &bh);
+
+ if (error)
+ goto fail;
+
+ gfs2_trans_add_meta(ip->i_gl, bh);
+ memcpy(bh->b_data + o, buf, amount);
+ brelse(bh);
+
+ buf += amount;
+ copied += amount;
+ lblock++;
+ dblock++;
+ extlen--;
+
+ o = sizeof(struct gfs2_meta_header);
+ }
+
+out:
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (error)
+ return error;
+
+ if (ip->i_inode.i_size < offset + copied)
+ i_size_write(&ip->i_inode, offset + copied);
+ ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+
+ gfs2_trans_add_meta(ip->i_gl, dibh);
+ gfs2_dinode_out(ip, dibh->b_data);
+ brelse(dibh);
+
+ return copied;
+fail:
+ if (copied)
+ goto out;
+ return error;
+}
+
+static int gfs2_dir_read_stuffed(struct gfs2_inode *ip, __be64 *buf,
+ unsigned int size)
+{
+ struct buffer_head *dibh;
+ int error;
+
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (!error) {
+ memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
+ brelse(dibh);
+ }
+
+ return (error) ? error : size;
+}
+
+
+/**
+ * gfs2_dir_read_data - Read a data from a directory inode
+ * @ip: The GFS2 Inode
+ * @buf: The buffer to place result into
+ * @size: Amount of data to transfer
+ *
+ * Returns: The amount of data actually copied or the error
+ */
+static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
+ unsigned int size)
+{
+ struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+ u64 lblock, dblock;
+ u32 extlen = 0;
+ unsigned int o;
+ int copied = 0;
+ int error = 0;
+
+ if (gfs2_is_stuffed(ip))
+ return gfs2_dir_read_stuffed(ip, buf, size);
+
+ if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
+ return -EINVAL;
+
+ lblock = 0;
+ o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
+
+ while (copied < size) {
+ unsigned int amount;
+ struct buffer_head *bh;
+ int new;
+
+ amount = size - copied;
+ if (amount > sdp->sd_sb.sb_bsize - o)
+ amount = sdp->sd_sb.sb_bsize - o;
+
+ if (!extlen) {
+ new = 0;
+ error = gfs2_extent_map(&ip->i_inode, lblock, &new,
+ &dblock, &extlen);
+ if (error || !dblock)
+ goto fail;
+ BUG_ON(extlen < 1);
+ bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
+ } else {
+ error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, 0, &bh);
+ if (error)
+ goto fail;
+ }
+ error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
+ if (error) {
+ brelse(bh);
+ goto fail;
+ }
+ dblock++;
+ extlen--;
+ memcpy(buf, bh->b_data + o, amount);
+ brelse(bh);
+ buf += (amount/sizeof(__be64));
+ copied += amount;
+ lblock++;
+ o = sizeof(struct gfs2_meta_header);
+ }
+
+ return copied;
+fail:
+ return (copied) ? copied : error;
+}
+
+/**
+ * gfs2_dir_get_hash_table - Get pointer to the dir hash table
+ * @ip: The inode in question
+ *
+ * Returns: The hash table or an error
+ */
+
+static __be64 *gfs2_dir_get_hash_table(struct gfs2_inode *ip)
+{
+ struct inode *inode = &ip->i_inode;
+ int ret;
+ u32 hsize;
+ __be64 *hc;
+
+ BUG_ON(!(ip->i_diskflags & GFS2_DIF_EXHASH));
+
+ hc = ip->i_hash_cache;
+ if (hc)
+ return hc;
+
+ hsize = BIT(ip->i_depth);
+ hsize *= sizeof(__be64);
+ if (hsize != i_size_read(&ip->i_inode)) {
+ gfs2_consist_inode(ip);
+ return ERR_PTR(-EIO);
+ }
+
+ hc = kmalloc(hsize, GFP_NOFS | __GFP_NOWARN);
+ if (hc == NULL)
+ hc = __vmalloc(hsize, GFP_NOFS, PAGE_KERNEL);
+
+ if (hc == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ ret = gfs2_dir_read_data(ip, hc, hsize);
+ if (ret < 0) {
+ kvfree(hc);
+ return ERR_PTR(ret);
+ }
+
+ spin_lock(&inode->i_lock);
+ if (likely(!ip->i_hash_cache)) {
+ ip->i_hash_cache = hc;
+ hc = NULL;
+ }
+ spin_unlock(&inode->i_lock);
+ kvfree(hc);
+
+ return ip->i_hash_cache;
+}
+
+/**
+ * gfs2_dir_hash_inval - Invalidate dir hash
+ * @ip: The directory inode
+ *
+ * Must be called with an exclusive glock, or during glock invalidation.
+ */
+void gfs2_dir_hash_inval(struct gfs2_inode *ip)
+{
+ __be64 *hc;
+
+ spin_lock(&ip->i_inode.i_lock);
+ hc = ip->i_hash_cache;
+ ip->i_hash_cache = NULL;
+ spin_unlock(&ip->i_inode.i_lock);
+
+ kvfree(hc);
+}
+
+static inline int gfs2_dirent_sentinel(const struct gfs2_dirent *dent)
+{
+ return dent->de_inum.no_addr == 0 || dent->de_inum.no_formal_ino == 0;
+}
+
+static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
+ const struct qstr *name, int ret)
+{
+ if (!gfs2_dirent_sentinel(dent) &&
+ be32_to_cpu(dent->de_hash) == name->hash &&
+ be16_to_cpu(dent->de_name_len) == name->len &&
+ memcmp(dent+1, name->name, name->len) == 0)
+ return ret;
+ return 0;
+}
+
+static int gfs2_dirent_find(const struct gfs2_dirent *dent,
+ const struct qstr *name,
+ void *opaque)
+{
+ return __gfs2_dirent_find(dent, name, 1);
+}
+
+static int gfs2_dirent_prev(const struct gfs2_dirent *dent,
+ const struct qstr *name,
+ void *opaque)
+{
+ return __gfs2_dirent_find(dent, name, 2);
+}
+
+/*
+ * name->name holds ptr to start of block.
+ * name->len holds size of block.
+ */
+static int gfs2_dirent_last(const struct gfs2_dirent *dent,
+ const struct qstr *name,
+ void *opaque)
+{
+ const char *start = name->name;
+ const char *end = (const char *)dent + be16_to_cpu(dent->de_rec_len);
+ if (name->len == (end - start))
+ return 1;
+ return 0;
+}
+
+/* Look for the dirent that contains the offset specified in data. Once we
+ * find that dirent, there must be space available there for the new dirent */
+static int gfs2_dirent_find_offset(const struct gfs2_dirent *dent,
+ const struct qstr *name,
+ void *ptr)
+{
+ unsigned required = GFS2_DIRENT_SIZE(name->len);
+ unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
+ unsigned totlen = be16_to_cpu(dent->de_rec_len);
+
+ if (ptr < (void *)dent || ptr >= (void *)dent + totlen)
+ return 0;
+ if (gfs2_dirent_sentinel(dent))
+ actual = 0;
+ if (ptr < (void *)dent + actual)
+ return -1;
+ if ((void *)dent + totlen >= ptr + required)
+ return 1;
+ return -1;
+}
+
+static int gfs2_dirent_find_space(const struct gfs2_dirent *dent,
+ const struct qstr *name,
+ void *opaque)
+{
+ unsigned required = GFS2_DIRENT_SIZE(name->len);
+ unsigned actual = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
+ unsigned totlen = be16_to_cpu(dent->de_rec_len);
+
+ if (gfs2_dirent_sentinel(dent))
+ actual = 0;
+ if (totlen - actual >= required)
+ return 1;
+ return 0;
+}
+
+struct dirent_gather {
+ const struct gfs2_dirent **pdent;
+ unsigned offset;
+};
+
+static int gfs2_dirent_gather(const struct gfs2_dirent *dent,
+ const struct qstr *name,
+ void *opaque)
+{
+ struct dirent_gather *g = opaque;
+ if (!gfs2_dirent_sentinel(dent)) {
+ g->pdent[g->offset++] = dent;
+ }
+ return 0;
+}
+
+/*
+ * Other possible things to check:
+ * - Inode located within filesystem size (and on valid block)
+ * - Valid directory entry type
+ * Not sure how heavy-weight we want to make this... could also check
+ * hash is correct for example, but that would take a lot of extra time.
+ * For now the most important thing is to check that the various sizes
+ * are correct.
+ */
+static int gfs2_check_dirent(struct gfs2_dirent *dent, unsigned int offset,
+ unsigned int size, unsigned int len, int first)
+{
+ const char *msg = "gfs2_dirent too small";
+ if (unlikely(size < sizeof(struct gfs2_dirent)))
+ goto error;
+ msg = "gfs2_dirent misaligned";
+ if (unlikely(offset & 0x7))
+ goto error;
+ msg = "gfs2_dirent points beyond end of block";
+ if (unlikely(offset + size > len))
+ goto error;
+ msg = "zero inode number";
+ if (unlikely(!first && gfs2_dirent_sentinel(dent)))
+ goto error;
+ msg = "name length is greater than space in dirent";
+ if (!gfs2_dirent_sentinel(dent) &&
+ unlikely(sizeof(struct gfs2_dirent)+be16_to_cpu(dent->de_name_len) >
+ size))
+ goto error;
+ return 0;
+error:
+ pr_warn("%s: %s (%s)\n",
+ __func__, msg, first ? "first in block" : "not first in block");
+ return -EIO;
+}
+
+static int gfs2_dirent_offset(const void *buf)
+{
+ const struct gfs2_meta_header *h = buf;
+ int offset;
+
+ BUG_ON(buf == NULL);
+
+ switch(be32_to_cpu(h->mh_type)) {
+ case GFS2_METATYPE_LF:
+ offset = sizeof(struct gfs2_leaf);
+ break;
+ case GFS2_METATYPE_DI:
+ offset = sizeof(struct gfs2_dinode);
+ break;
+ default:
+ goto wrong_type;
+ }
+ return offset;
+wrong_type:
+ pr_warn("%s: wrong block type %u\n", __func__, be32_to_cpu(h->mh_type));
+ return -1;
+}
+
+static struct gfs2_dirent *gfs2_dirent_scan(struct inode *inode, void *buf,
+ unsigned int len, gfs2_dscan_t scan,
+ const struct qstr *name,
+ void *opaque)
+{
+ struct gfs2_dirent *dent, *prev;
+ unsigned offset;
+ unsigned size;
+ int ret = 0;
+
+ ret = gfs2_dirent_offset(buf);
+ if (ret < 0)
+ goto consist_inode;
+
+ offset = ret;
+ prev = NULL;
+ dent = buf + offset;
+ size = be16_to_cpu(dent->de_rec_len);
+ if (gfs2_check_dirent(dent, offset, size, len, 1))
+ goto consist_inode;
+ do {
+ ret = scan(dent, name, opaque);
+ if (ret)
+ break;
+ offset += size;
+ if (offset == len)
+ break;
+ prev = dent;
+ dent = buf + offset;
+ size = be16_to_cpu(dent->de_rec_len);
+ if (gfs2_check_dirent(dent, offset, size, len, 0))
+ goto consist_inode;
+ } while(1);
+
+ switch(ret) {
+ case 0:
+ return NULL;
+ case 1:
+ return dent;
+ case 2:
+ return prev ? prev : dent;
+ default:
+ BUG_ON(ret > 0);
+ return ERR_PTR(ret);
+ }
+
+consist_inode:
+ gfs2_consist_inode(GFS2_I(inode));
+ return ERR_PTR(-EIO);
+}
+
+static int dirent_check_reclen(struct gfs2_inode *dip,
+ const struct gfs2_dirent *d, const void *end_p)
+{
+ const void *ptr = d;
+ u16 rec_len = be16_to_cpu(d->de_rec_len);
+
+ if (unlikely(rec_len < sizeof(struct gfs2_dirent)))
+ goto broken;
+ ptr += rec_len;
+ if (ptr < end_p)
+ return rec_len;
+ if (ptr == end_p)
+ return -ENOENT;
+broken:
+ gfs2_consist_inode(dip);
+ return -EIO;
+}
+
+/**
+ * dirent_next - Next dirent
+ * @dip: the directory
+ * @bh: The buffer
+ * @dent: Pointer to list of dirents
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+static int dirent_next(struct gfs2_inode *dip, struct buffer_head *bh,
+ struct gfs2_dirent **dent)
+{
+ struct gfs2_dirent *cur = *dent, *tmp;
+ char *bh_end = bh->b_data + bh->b_size;
+ int ret;
+
+ ret = dirent_check_reclen(dip, cur, bh_end);
+ if (ret < 0)
+ return ret;
+
+ tmp = (void *)cur + ret;
+ ret = dirent_check_reclen(dip, tmp, bh_end);
+ if (ret == -EIO)
+ return ret;
+
+ /* Only the first dent could ever have de_inum.no_addr == 0 */
+ if (gfs2_dirent_sentinel(tmp)) {
+ gfs2_consist_inode(dip);
+ return -EIO;
+ }
+
+ *dent = tmp;
+ return 0;
+}
+
+/**
+ * dirent_del - Delete a dirent
+ * @dip: The GFS2 inode
+ * @bh: The buffer
+ * @prev: The previous dirent
+ * @cur: The current dirent
+ *
+ */
+
+static void dirent_del(struct gfs2_inode *dip, struct buffer_head *bh,
+ struct gfs2_dirent *prev, struct gfs2_dirent *cur)
+{
+ u16 cur_rec_len, prev_rec_len;
+
+ if (gfs2_dirent_sentinel(cur)) {
+ gfs2_consist_inode(dip);
+ return;
+ }
+
+ gfs2_trans_add_meta(dip->i_gl, bh);
+
+ /* If there is no prev entry, this is the first entry in the block.
+ The de_rec_len is already as big as it needs to be. Just zero
+ out the inode number and return. */
+
+ if (!prev) {
+ cur->de_inum.no_addr = 0;
+ cur->de_inum.no_formal_ino = 0;
+ return;
+ }
+
+ /* Combine this dentry with the previous one. */
+
+ prev_rec_len = be16_to_cpu(prev->de_rec_len);
+ cur_rec_len = be16_to_cpu(cur->de_rec_len);
+
+ if ((char *)prev + prev_rec_len != (char *)cur)
+ gfs2_consist_inode(dip);
+ if ((char *)cur + cur_rec_len > bh->b_data + bh->b_size)
+ gfs2_consist_inode(dip);
+
+ prev_rec_len += cur_rec_len;
+ prev->de_rec_len = cpu_to_be16(prev_rec_len);
+}
+
+
+static struct gfs2_dirent *do_init_dirent(struct inode *inode,
+ struct gfs2_dirent *dent,
+ const struct qstr *name,
+ struct buffer_head *bh,
+ unsigned offset)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_dirent *ndent;
+ unsigned totlen;
+
+ totlen = be16_to_cpu(dent->de_rec_len);
+ BUG_ON(offset + name->len > totlen);
+ gfs2_trans_add_meta(ip->i_gl, bh);
+ ndent = (struct gfs2_dirent *)((char *)dent + offset);
+ dent->de_rec_len = cpu_to_be16(offset);
+ gfs2_qstr2dirent(name, totlen - offset, ndent);
+ return ndent;
+}
+
+
+/*
+ * Takes a dent from which to grab space as an argument. Returns the
+ * newly created dent.
+ */
+static struct gfs2_dirent *gfs2_init_dirent(struct inode *inode,
+ struct gfs2_dirent *dent,
+ const struct qstr *name,
+ struct buffer_head *bh)
+{
+ unsigned offset = 0;
+
+ if (!gfs2_dirent_sentinel(dent))
+ offset = GFS2_DIRENT_SIZE(be16_to_cpu(dent->de_name_len));
+ return do_init_dirent(inode, dent, name, bh, offset);
+}
+
+static struct gfs2_dirent *gfs2_dirent_split_alloc(struct inode *inode,
+ struct buffer_head *bh,
+ const struct qstr *name,
+ void *ptr)
+{
+ struct gfs2_dirent *dent;
+ dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
+ gfs2_dirent_find_offset, name, ptr);
+ if (!dent || IS_ERR(dent))
+ return dent;
+ return do_init_dirent(inode, dent, name, bh,
+ (unsigned)(ptr - (void *)dent));
+}
+
+static int get_leaf(struct gfs2_inode *dip, u64 leaf_no,
+ struct buffer_head **bhp)
+{
+ int error;
+
+ error = gfs2_meta_read(dip->i_gl, leaf_no, DIO_WAIT, 0, bhp);
+ if (!error && gfs2_metatype_check(GFS2_SB(&dip->i_inode), *bhp, GFS2_METATYPE_LF)) {
+ /* pr_info("block num=%llu\n", leaf_no); */
+ error = -EIO;
+ }
+
+ return error;
+}
+
+/**
+ * get_leaf_nr - Get a leaf number associated with the index
+ * @dip: The GFS2 inode
+ * @index:
+ * @leaf_out:
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+static int get_leaf_nr(struct gfs2_inode *dip, u32 index,
+ u64 *leaf_out)
+{
+ __be64 *hash;
+ int error;
+
+ hash = gfs2_dir_get_hash_table(dip);
+ error = PTR_ERR_OR_ZERO(hash);
+
+ if (!error)
+ *leaf_out = be64_to_cpu(*(hash + index));
+
+ return error;
+}
+
+static int get_first_leaf(struct gfs2_inode *dip, u32 index,
+ struct buffer_head **bh_out)
+{
+ u64 leaf_no;
+ int error;
+
+ error = get_leaf_nr(dip, index, &leaf_no);
+ if (!error)
+ error = get_leaf(dip, leaf_no, bh_out);
+
+ return error;
+}
+
+static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
+ const struct qstr *name,
+ gfs2_dscan_t scan,
+ struct buffer_head **pbh)
+{
+ struct buffer_head *bh;
+ struct gfs2_dirent *dent;
+ struct gfs2_inode *ip = GFS2_I(inode);
+ int error;
+
+ if (ip->i_diskflags & GFS2_DIF_EXHASH) {
+ struct gfs2_leaf *leaf;
+ unsigned int hsize = BIT(ip->i_depth);
+ unsigned int index;
+ u64 ln;
+ if (hsize * sizeof(u64) != i_size_read(inode)) {
+ gfs2_consist_inode(ip);
+ return ERR_PTR(-EIO);
+ }
+
+ index = name->hash >> (32 - ip->i_depth);
+ error = get_first_leaf(ip, index, &bh);
+ if (error)
+ return ERR_PTR(error);
+ do {
+ dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
+ scan, name, NULL);
+ if (dent)
+ goto got_dent;
+ leaf = (struct gfs2_leaf *)bh->b_data;
+ ln = be64_to_cpu(leaf->lf_next);
+ brelse(bh);
+ if (!ln)
+ break;
+
+ error = get_leaf(ip, ln, &bh);
+ } while(!error);
+
+ return error ? ERR_PTR(error) : NULL;
+ }
+
+
+ error = gfs2_meta_inode_buffer(ip, &bh);
+ if (error)
+ return ERR_PTR(error);
+ dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
+got_dent:
+ if (unlikely(dent == NULL || IS_ERR(dent))) {
+ brelse(bh);
+ bh = NULL;
+ }
+ *pbh = bh;
+ return dent;
+}
+
+static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh, u16 depth)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ unsigned int n = 1;
+ u64 bn;
+ int error;
+ struct buffer_head *bh;
+ struct gfs2_leaf *leaf;
+ struct gfs2_dirent *dent;
+ struct timespec tv = current_time(inode);
+
+ error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);
+ if (error)
+ return NULL;
+ bh = gfs2_meta_new(ip->i_gl, bn);
+ if (!bh)
+ return NULL;
+
+ gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, 1);
+ gfs2_trans_add_meta(ip->i_gl, bh);
+ gfs2_metatype_set(bh, GFS2_METATYPE_LF, GFS2_FORMAT_LF);
+ leaf = (struct gfs2_leaf *)bh->b_data;
+ leaf->lf_depth = cpu_to_be16(depth);
+ leaf->lf_entries = 0;
+ leaf->lf_dirent_format = cpu_to_be32(GFS2_FORMAT_DE);
+ leaf->lf_next = 0;
+ leaf->lf_inode = cpu_to_be64(ip->i_no_addr);
+ leaf->lf_dist = cpu_to_be32(1);
+ leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
+ leaf->lf_sec = cpu_to_be64(tv.tv_sec);
+ memset(leaf->lf_reserved2, 0, sizeof(leaf->lf_reserved2));
+ dent = (struct gfs2_dirent *)(leaf+1);
+ gfs2_qstr2dirent(&empty_name, bh->b_size - sizeof(struct gfs2_leaf), dent);
+ *pbh = bh;
+ return leaf;
+}
+
+/**
+ * dir_make_exhash - Convert a stuffed directory into an ExHash directory
+ * @dip: The GFS2 inode
+ *
+ * Returns: 0 on success, error code otherwise
+ */
+
+static int dir_make_exhash(struct inode *inode)
+{
+ struct gfs2_inode *dip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_dirent *dent;
+ struct qstr args;
+ struct buffer_head *bh, *dibh;
+ struct gfs2_leaf *leaf;
+ int y;
+ u32 x;
+ __be64 *lp;
+ u64 bn;
+ int error;
+
+ error = gfs2_meta_inode_buffer(dip, &dibh);
+ if (error)
+ return error;
+
+ /* Turn over a new leaf */
+
+ leaf = new_leaf(inode, &bh, 0);
+ if (!leaf)
+ return -ENOSPC;
+ bn = bh->b_blocknr;
+
+ gfs2_assert(sdp, dip->i_entries < BIT(16));
+ leaf->lf_entries = cpu_to_be16(dip->i_entries);
+
+ /* Copy dirents */
+
+ gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_leaf), dibh,
+ sizeof(struct gfs2_dinode));
+
+ /* Find last entry */
+
+ x = 0;
+ args.len = bh->b_size - sizeof(struct gfs2_dinode) +
+ sizeof(struct gfs2_leaf);
+ args.name = bh->b_data;
+ dent = gfs2_dirent_scan(&dip->i_inode, bh->b_data, bh->b_size,
+ gfs2_dirent_last, &args, NULL);
+ if (!dent) {
+ brelse(bh);
+ brelse(dibh);
+ return -EIO;
+ }
+ if (IS_ERR(dent)) {
+ brelse(bh);
+ brelse(dibh);
+ return PTR_ERR(dent);
+ }
+
+ /* Adjust the last dirent's record length
+ (Remember that dent still points to the last entry.) */
+
+ dent->de_rec_len = cpu_to_be16(be16_to_cpu(dent->de_rec_len) +
+ sizeof(struct gfs2_dinode) -
+ sizeof(struct gfs2_leaf));
+
+ brelse(bh);
+
+ /* We're done with the new leaf block, now setup the new
+ hash table. */
+
+ gfs2_trans_add_meta(dip->i_gl, dibh);
+ gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
+
+ lp = (__be64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
+
+ for (x = sdp->sd_hash_ptrs; x--; lp++)
+ *lp = cpu_to_be64(bn);
+
+ i_size_write(inode, sdp->sd_sb.sb_bsize / 2);
+ gfs2_add_inode_blocks(&dip->i_inode, 1);
+ dip->i_diskflags |= GFS2_DIF_EXHASH;
+
+ for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
+ dip->i_depth = y;
+
+ gfs2_dinode_out(dip, dibh->b_data);
+
+ brelse(dibh);
+
+ return 0;
+}
+
+/**
+ * dir_split_leaf - Split a leaf block into two
+ * @dip: The GFS2 inode
+ * @index:
+ * @leaf_no:
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+static int dir_split_leaf(struct inode *inode, const struct qstr *name)
+{
+ struct gfs2_inode *dip = GFS2_I(inode);
+ struct buffer_head *nbh, *obh, *dibh;
+ struct gfs2_leaf *nleaf, *oleaf;
+ struct gfs2_dirent *dent = NULL, *prev = NULL, *next = NULL, *new;
+ u32 start, len, half_len, divider;
+ u64 bn, leaf_no;
+ __be64 *lp;
+ u32 index;
+ int x, moved = 0;
+ int error;
+
+ index = name->hash >> (32 - dip->i_depth);
+ error = get_leaf_nr(dip, index, &leaf_no);
+ if (error)
+ return error;
+
+ /* Get the old leaf block */
+ error = get_leaf(dip, leaf_no, &obh);
+ if (error)
+ return error;
+
+ oleaf = (struct gfs2_leaf *)obh->b_data;
+ if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
+ brelse(obh);
+ return 1; /* can't split */
+ }
+
+ gfs2_trans_add_meta(dip->i_gl, obh);
+
+ nleaf = new_leaf(inode, &nbh, be16_to_cpu(oleaf->lf_depth) + 1);
+ if (!nleaf) {
+ brelse(obh);
+ return -ENOSPC;
+ }
+ bn = nbh->b_blocknr;
+
+ /* Compute the start and len of leaf pointers in the hash table. */
+ len = BIT(dip->i_depth - be16_to_cpu(oleaf->lf_depth));
+ half_len = len >> 1;
+ if (!half_len) {
+ pr_warn("i_depth %u lf_depth %u index %u\n",
+ dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
+ gfs2_consist_inode(dip);
+ error = -EIO;
+ goto fail_brelse;
+ }
+
+ start = (index & ~(len - 1));
+
+ /* Change the pointers.
+ Don't bother distinguishing stuffed from non-stuffed.
+ This code is complicated enough already. */
+ lp = kmalloc(half_len * sizeof(__be64), GFP_NOFS);
+ if (!lp) {
+ error = -ENOMEM;
+ goto fail_brelse;
+ }
+
+ /* Change the pointers */
+ for (x = 0; x < half_len; x++)
+ lp[x] = cpu_to_be64(bn);
+
+ gfs2_dir_hash_inval(dip);
+
+ error = gfs2_dir_write_data(dip, (char *)lp, start * sizeof(u64),
+ half_len * sizeof(u64));
+ if (error != half_len * sizeof(u64)) {
+ if (error >= 0)
+ error = -EIO;
+ goto fail_lpfree;
+ }
+
+ kfree(lp);
+
+ /* Compute the divider */
+ divider = (start + half_len) << (32 - dip->i_depth);
+
+ /* Copy the entries */
+ dent = (struct gfs2_dirent *)(obh->b_data + sizeof(struct gfs2_leaf));
+
+ do {
+ next = dent;
+ if (dirent_next(dip, obh, &next))
+ next = NULL;
+
+ if (!gfs2_dirent_sentinel(dent) &&
+ be32_to_cpu(dent->de_hash) < divider) {
+ struct qstr str;
+ void *ptr = ((char *)dent - obh->b_data) + nbh->b_data;
+ str.name = (char*)(dent+1);
+ str.len = be16_to_cpu(dent->de_name_len);
+ str.hash = be32_to_cpu(dent->de_hash);
+ new = gfs2_dirent_split_alloc(inode, nbh, &str, ptr);
+ if (IS_ERR(new)) {
+ error = PTR_ERR(new);
+ break;
+ }
+
+ new->de_inum = dent->de_inum; /* No endian worries */
+ new->de_type = dent->de_type; /* No endian worries */
+ be16_add_cpu(&nleaf->lf_entries, 1);
+
+ dirent_del(dip, obh, prev, dent);
+
+ if (!oleaf->lf_entries)
+ gfs2_consist_inode(dip);
+ be16_add_cpu(&oleaf->lf_entries, -1);
+
+ if (!prev)
+ prev = dent;
+
+ moved = 1;
+ } else {
+ prev = dent;
+ }
+ dent = next;
+ } while (dent);
+
+ oleaf->lf_depth = nleaf->lf_depth;
+
+ error = gfs2_meta_inode_buffer(dip, &dibh);
+ if (!gfs2_assert_withdraw(GFS2_SB(&dip->i_inode), !error)) {
+ gfs2_trans_add_meta(dip->i_gl, dibh);
+ gfs2_add_inode_blocks(&dip->i_inode, 1);
+ gfs2_dinode_out(dip, dibh->b_data);
+ brelse(dibh);
+ }
+
+ brelse(obh);
+ brelse(nbh);
+
+ return error;
+
+fail_lpfree:
+ kfree(lp);
+
+fail_brelse:
+ brelse(obh);
+ brelse(nbh);
+ return error;
+}
+
+/**
+ * dir_double_exhash - Double size of ExHash table
+ * @dip: The GFS2 dinode
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+static int dir_double_exhash(struct gfs2_inode *dip)
+{
+ struct buffer_head *dibh;
+ u32 hsize;
+ u32 hsize_bytes;
+ __be64 *hc;
+ __be64 *hc2, *h;
+ int x;
+ int error = 0;
+
+ hsize = BIT(dip->i_depth);
+ hsize_bytes = hsize * sizeof(__be64);
+
+ hc = gfs2_dir_get_hash_table(dip);
+ if (IS_ERR(hc))
+ return PTR_ERR(hc);
+
+ hc2 = kmalloc(hsize_bytes * 2, GFP_NOFS | __GFP_NOWARN);
+ if (hc2 == NULL)
+ hc2 = __vmalloc(hsize_bytes * 2, GFP_NOFS, PAGE_KERNEL);
+
+ if (!hc2)
+ return -ENOMEM;
+
+ h = hc2;
+ error = gfs2_meta_inode_buffer(dip, &dibh);
+ if (error)
+ goto out_kfree;
+
+ for (x = 0; x < hsize; x++) {
+ *h++ = *hc;
+ *h++ = *hc;
+ hc++;
+ }
+
+ error = gfs2_dir_write_data(dip, (char *)hc2, 0, hsize_bytes * 2);
+ if (error != (hsize_bytes * 2))
+ goto fail;
+
+ gfs2_dir_hash_inval(dip);
+ dip->i_hash_cache = hc2;
+ dip->i_depth++;
+ gfs2_dinode_out(dip, dibh->b_data);
+ brelse(dibh);
+ return 0;
+
+fail:
+ /* Replace original hash table & size */
+ gfs2_dir_write_data(dip, (char *)hc, 0, hsize_bytes);
+ i_size_write(&dip->i_inode, hsize_bytes);
+ gfs2_dinode_out(dip, dibh->b_data);
+ brelse(dibh);
+out_kfree:
+ kvfree(hc2);
+ return error;
+}
+
+/**
+ * compare_dents - compare directory entries by hash value
+ * @a: first dent
+ * @b: second dent
+ *
+ * When comparing the hash entries of @a to @b:
+ * gt: returns 1
+ * lt: returns -1
+ * eq: returns 0
+ */
+
+static int compare_dents(const void *a, const void *b)
+{
+ const struct gfs2_dirent *dent_a, *dent_b;
+ u32 hash_a, hash_b;
+ int ret = 0;
+
+ dent_a = *(const struct gfs2_dirent **)a;
+ hash_a = dent_a->de_cookie;
+
+ dent_b = *(const struct gfs2_dirent **)b;
+ hash_b = dent_b->de_cookie;
+
+ if (hash_a > hash_b)
+ ret = 1;
+ else if (hash_a < hash_b)
+ ret = -1;
+ else {
+ unsigned int len_a = be16_to_cpu(dent_a->de_name_len);
+ unsigned int len_b = be16_to_cpu(dent_b->de_name_len);
+
+ if (len_a > len_b)
+ ret = 1;
+ else if (len_a < len_b)
+ ret = -1;
+ else
+ ret = memcmp(dent_a + 1, dent_b + 1, len_a);
+ }
+
+ return ret;
+}
+
+/**
+ * do_filldir_main - read out directory entries
+ * @dip: The GFS2 inode
+ * @ctx: what to feed the entries to
+ * @darr: an array of struct gfs2_dirent pointers to read
+ * @entries: the number of entries in darr
+ * @copied: pointer to int that's non-zero if a entry has been copied out
+ *
+ * Jump through some hoops to make sure that if there are hash collsions,
+ * they are read out at the beginning of a buffer. We want to minimize
+ * the possibility that they will fall into different readdir buffers or
+ * that someone will want to seek to that location.
+ *
+ * Returns: errno, >0 if the actor tells you to stop
+ */
+
+static int do_filldir_main(struct gfs2_inode *dip, struct dir_context *ctx,
+ struct gfs2_dirent **darr, u32 entries,
+ u32 sort_start, int *copied)
+{
+ const struct gfs2_dirent *dent, *dent_next;
+ u64 off, off_next;
+ unsigned int x, y;
+ int run = 0;
+
+ if (sort_start < entries)
+ sort(&darr[sort_start], entries - sort_start,
+ sizeof(struct gfs2_dirent *), compare_dents, NULL);
+
+ dent_next = darr[0];
+ off_next = dent_next->de_cookie;
+
+ for (x = 0, y = 1; x < entries; x++, y++) {
+ dent = dent_next;
+ off = off_next;
+
+ if (y < entries) {
+ dent_next = darr[y];
+ off_next = dent_next->de_cookie;
+
+ if (off < ctx->pos)
+ continue;
+ ctx->pos = off;
+
+ if (off_next == off) {
+ if (*copied && !run)
+ return 1;
+ run = 1;
+ } else
+ run = 0;
+ } else {
+ if (off < ctx->pos)
+ continue;
+ ctx->pos = off;
+ }
+
+ if (!dir_emit(ctx, (const char *)(dent + 1),
+ be16_to_cpu(dent->de_name_len),
+ be64_to_cpu(dent->de_inum.no_addr),
+ be16_to_cpu(dent->de_type)))
+ return 1;
+
+ *copied = 1;
+ }
+
+ /* Increment the ctx->pos by one, so the next time we come into the
+ do_filldir fxn, we get the next entry instead of the last one in the
+ current leaf */
+
+ ctx->pos++;
+
+ return 0;
+}
+
+static void *gfs2_alloc_sort_buffer(unsigned size)
+{
+ void *ptr = NULL;
+
+ if (size < KMALLOC_MAX_SIZE)
+ ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
+ if (!ptr)
+ ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
+ return ptr;
+}
+
+
+static int gfs2_set_cookies(struct gfs2_sbd *sdp, struct buffer_head *bh,
+ unsigned leaf_nr, struct gfs2_dirent **darr,
+ unsigned entries)
+{
+ int sort_id = -1;
+ int i;
+
+ for (i = 0; i < entries; i++) {
+ unsigned offset;
+
+ darr[i]->de_cookie = be32_to_cpu(darr[i]->de_hash);
+ darr[i]->de_cookie = gfs2_disk_hash2offset(darr[i]->de_cookie);
+
+ if (!sdp->sd_args.ar_loccookie)
+ continue;
+ offset = (char *)(darr[i]) -
+ (bh->b_data + gfs2_dirent_offset(bh->b_data));
+ offset /= GFS2_MIN_DIRENT_SIZE;
+ offset += leaf_nr * sdp->sd_max_dents_per_leaf;
+ if (offset >= GFS2_USE_HASH_FLAG ||
+ leaf_nr >= GFS2_USE_HASH_FLAG) {
+ darr[i]->de_cookie |= GFS2_USE_HASH_FLAG;
+ if (sort_id < 0)
+ sort_id = i;
+ continue;
+ }
+ darr[i]->de_cookie &= GFS2_HASH_INDEX_MASK;
+ darr[i]->de_cookie |= offset;
+ }
+ return sort_id;
+}
+
+
+static int gfs2_dir_read_leaf(struct inode *inode, struct dir_context *ctx,
+ int *copied, unsigned *depth,
+ u64 leaf_no)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct buffer_head *bh;
+ struct gfs2_leaf *lf;
+ unsigned entries = 0, entries2 = 0;
+ unsigned leaves = 0, leaf = 0, offset, sort_offset;
+ struct gfs2_dirent **darr, *dent;
+ struct dirent_gather g;
+ struct buffer_head **larr;
+ int error, i, need_sort = 0, sort_id;
+ u64 lfn = leaf_no;
+
+ do {
+ error = get_leaf(ip, lfn, &bh);
+ if (error)
+ goto out;
+ lf = (struct gfs2_leaf *)bh->b_data;
+ if (leaves == 0)
+ *depth = be16_to_cpu(lf->lf_depth);
+ entries += be16_to_cpu(lf->lf_entries);
+ leaves++;
+ lfn = be64_to_cpu(lf->lf_next);
+ brelse(bh);
+ } while(lfn);
+
+ if (*depth < GFS2_DIR_MAX_DEPTH || !sdp->sd_args.ar_loccookie) {
+ need_sort = 1;
+ sort_offset = 0;
+ }
+
+ if (!entries)
+ return 0;
+
+ error = -ENOMEM;
+ /*
+ * The extra 99 entries are not normally used, but are a buffer
+ * zone in case the number of entries in the leaf is corrupt.
+ * 99 is the maximum number of entries that can fit in a single
+ * leaf block.
+ */
+ larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
+ if (!larr)
+ goto out;
+ darr = (struct gfs2_dirent **)(larr + leaves);
+ g.pdent = (const struct gfs2_dirent **)darr;
+ g.offset = 0;
+ lfn = leaf_no;
+
+ do {
+ error = get_leaf(ip, lfn, &bh);
+ if (error)
+ goto out_free;
+ lf = (struct gfs2_leaf *)bh->b_data;
+ lfn = be64_to_cpu(lf->lf_next);
+ if (lf->lf_entries) {
+ offset = g.offset;
+ entries2 += be16_to_cpu(lf->lf_entries);
+ dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
+ gfs2_dirent_gather, NULL, &g);
+ error = PTR_ERR(dent);
+ if (IS_ERR(dent))
+ goto out_free;
+ if (entries2 != g.offset) {
+ fs_warn(sdp, "Number of entries corrupt in dir "
+ "leaf %llu, entries2 (%u) != "
+ "g.offset (%u)\n",
+ (unsigned long long)bh->b_blocknr,
+ entries2, g.offset);
+ gfs2_consist_inode(ip);
+ error = -EIO;
+ goto out_free;
+ }
+ error = 0;
+ sort_id = gfs2_set_cookies(sdp, bh, leaf, &darr[offset],
+ be16_to_cpu(lf->lf_entries));
+ if (!need_sort && sort_id >= 0) {
+ need_sort = 1;
+ sort_offset = offset + sort_id;
+ }
+ larr[leaf++] = bh;
+ } else {
+ larr[leaf++] = NULL;
+ brelse(bh);
+ }
+ } while(lfn);
+
+ BUG_ON(entries2 != entries);
+ error = do_filldir_main(ip, ctx, darr, entries, need_sort ?
+ sort_offset : entries, copied);
+out_free:
+ for(i = 0; i < leaf; i++)
+ if (larr[i])
+ brelse(larr[i]);
+ kvfree(larr);
+out:
+ return error;
+}
+
+/**
+ * gfs2_dir_readahead - Issue read-ahead requests for leaf blocks.
+ *
+ * Note: we can't calculate each index like dir_e_read can because we don't
+ * have the leaf, and therefore we don't have the depth, and therefore we
+ * don't have the length. So we have to just read enough ahead to make up
+ * for the loss of information.
+ */
+static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index,
+ struct file_ra_state *f_ra)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_glock *gl = ip->i_gl;
+ struct buffer_head *bh;
+ u64 blocknr = 0, last;
+ unsigned count;
+
+ /* First check if we've already read-ahead for the whole range. */
+ if (index + MAX_RA_BLOCKS < f_ra->start)
+ return;
+
+ f_ra->start = max((pgoff_t)index, f_ra->start);
+ for (count = 0; count < MAX_RA_BLOCKS; count++) {
+ if (f_ra->start >= hsize) /* if exceeded the hash table */
+ break;
+
+ last = blocknr;
+ blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]);
+ f_ra->start++;
+ if (blocknr == last)
+ continue;
+
+ bh = gfs2_getbuf(gl, blocknr, 1);
+ if (trylock_buffer(bh)) {
+ if (buffer_uptodate(bh)) {
+ unlock_buffer(bh);
+ brelse(bh);
+ continue;
+ }
+ bh->b_end_io = end_buffer_read_sync;
+ submit_bh(REQ_OP_READ,
+ REQ_RAHEAD | REQ_META | REQ_PRIO,
+ bh);
+ continue;
+ }
+ brelse(bh);
+ }
+}
+
+/**
+ * dir_e_read - Reads the entries from a directory into a filldir buffer
+ * @dip: dinode pointer
+ * @ctx: actor to feed the entries to
+ *
+ * Returns: errno
+ */
+
+static int dir_e_read(struct inode *inode, struct dir_context *ctx,
+ struct file_ra_state *f_ra)
+{
+ struct gfs2_inode *dip = GFS2_I(inode);
+ u32 hsize, len = 0;
+ u32 hash, index;
+ __be64 *lp;
+ int copied = 0;
+ int error = 0;
+ unsigned depth = 0;
+
+ hsize = BIT(dip->i_depth);
+ hash = gfs2_dir_offset2hash(ctx->pos);
+ index = hash >> (32 - dip->i_depth);
+
+ if (dip->i_hash_cache == NULL)
+ f_ra->start = 0;
+ lp = gfs2_dir_get_hash_table(dip);
+ if (IS_ERR(lp))
+ return PTR_ERR(lp);
+
+ gfs2_dir_readahead(inode, hsize, index, f_ra);
+
+ while (index < hsize) {
+ error = gfs2_dir_read_leaf(inode, ctx,
+ &copied, &depth,
+ be64_to_cpu(lp[index]));
+ if (error)
+ break;
+
+ len = BIT(dip->i_depth - depth);
+ index = (index & ~(len - 1)) + len;
+ }
+
+ if (error > 0)
+ error = 0;
+ return error;
+}
+
+int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
+ struct file_ra_state *f_ra)
+{
+ struct gfs2_inode *dip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct dirent_gather g;
+ struct gfs2_dirent **darr, *dent;
+ struct buffer_head *dibh;
+ int copied = 0;
+ int error;
+
+ if (!dip->i_entries)
+ return 0;
+
+ if (dip->i_diskflags & GFS2_DIF_EXHASH)
+ return dir_e_read(inode, ctx, f_ra);
+
+ if (!gfs2_is_stuffed(dip)) {
+ gfs2_consist_inode(dip);
+ return -EIO;
+ }
+
+ error = gfs2_meta_inode_buffer(dip, &dibh);
+ if (error)
+ return error;
+
+ error = -ENOMEM;
+ /* 96 is max number of dirents which can be stuffed into an inode */
+ darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
+ if (darr) {
+ g.pdent = (const struct gfs2_dirent **)darr;
+ g.offset = 0;
+ dent = gfs2_dirent_scan(inode, dibh->b_data, dibh->b_size,
+ gfs2_dirent_gather, NULL, &g);
+ if (IS_ERR(dent)) {
+ error = PTR_ERR(dent);
+ goto out;
+ }
+ if (dip->i_entries != g.offset) {
+ fs_warn(sdp, "Number of entries corrupt in dir %llu, "
+ "ip->i_entries (%u) != g.offset (%u)\n",
+ (unsigned long long)dip->i_no_addr,
+ dip->i_entries,
+ g.offset);
+ gfs2_consist_inode(dip);
+ error = -EIO;
+ goto out;
+ }
+ gfs2_set_cookies(sdp, dibh, 0, darr, dip->i_entries);
+ error = do_filldir_main(dip, ctx, darr,
+ dip->i_entries, 0, &copied);
+out:
+ kfree(darr);
+ }
+
+ if (error > 0)
+ error = 0;
+
+ brelse(dibh);
+
+ return error;
+}
+
+/**
+ * gfs2_dir_search - Search a directory
+ * @dip: The GFS2 dir inode
+ * @name: The name we are looking up
+ * @fail_on_exist: Fail if the name exists rather than looking it up
+ *
+ * This routine searches a directory for a file or another directory.
+ * Assumes a glock is held on dip.
+ *
+ * Returns: errno
+ */
+
+struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name,
+ bool fail_on_exist)
+{
+ struct buffer_head *bh;
+ struct gfs2_dirent *dent;
+ u64 addr, formal_ino;
+ u16 dtype;
+
+ dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
+ if (dent) {
+ struct inode *inode;
+ u16 rahead;
+
+ if (IS_ERR(dent))
+ return ERR_CAST(dent);
+ dtype = be16_to_cpu(dent->de_type);
+ rahead = be16_to_cpu(dent->de_rahead);
+ addr = be64_to_cpu(dent->de_inum.no_addr);
+ formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino);
+ brelse(bh);
+ if (fail_on_exist)
+ return ERR_PTR(-EEXIST);
+ inode = gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino,
+ GFS2_BLKST_FREE /* ignore */);
+ if (!IS_ERR(inode))
+ GFS2_I(inode)->i_rahead = rahead;
+ return inode;
+ }
+ return ERR_PTR(-ENOENT);
+}
+
+int gfs2_dir_check(struct inode *dir, const struct qstr *name,
+ const struct gfs2_inode *ip)
+{
+ struct buffer_head *bh;
+ struct gfs2_dirent *dent;
+ int ret = -ENOENT;
+
+ dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
+ if (dent) {
+ if (IS_ERR(dent))
+ return PTR_ERR(dent);
+ if (ip) {
+ if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
+ goto out;
+ if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
+ ip->i_no_formal_ino)
+ goto out;
+ if (unlikely(IF2DT(ip->i_inode.i_mode) !=
+ be16_to_cpu(dent->de_type))) {
+ gfs2_consist_inode(GFS2_I(dir));
+ ret = -EIO;
+ goto out;
+ }
+ }
+ ret = 0;
+out:
+ brelse(bh);
+ }
+ return ret;
+}
+
+/**
+ * dir_new_leaf - Add a new leaf onto hash chain
+ * @inode: The directory
+ * @name: The name we are adding
+ *
+ * This adds a new dir leaf onto an existing leaf when there is not
+ * enough space to add a new dir entry. This is a last resort after
+ * we've expanded the hash table to max size and also split existing
+ * leaf blocks, so it will only occur for very large directories.
+ *
+ * The dist parameter is set to 1 for leaf blocks directly attached
+ * to the hash table, 2 for one layer of indirection, 3 for two layers
+ * etc. We are thus able to tell the difference between an old leaf
+ * with dist set to zero (i.e. "don't know") and a new one where we
+ * set this information for debug/fsck purposes.
+ *
+ * Returns: 0 on success, or -ve on error
+ */
+
+static int dir_new_leaf(struct inode *inode, const struct qstr *name)
+{
+ struct buffer_head *bh, *obh;
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_leaf *leaf, *oleaf;
+ u32 dist = 1;
+ int error;
+ u32 index;
+ u64 bn;
+
+ index = name->hash >> (32 - ip->i_depth);
+ error = get_first_leaf(ip, index, &obh);
+ if (error)
+ return error;
+ do {
+ dist++;
+ oleaf = (struct gfs2_leaf *)obh->b_data;
+ bn = be64_to_cpu(oleaf->lf_next);
+ if (!bn)
+ break;
+ brelse(obh);
+ error = get_leaf(ip, bn, &obh);
+ if (error)
+ return error;
+ } while(1);
+
+ gfs2_trans_add_meta(ip->i_gl, obh);
+
+ leaf = new_leaf(inode, &bh, be16_to_cpu(oleaf->lf_depth));
+ if (!leaf) {
+ brelse(obh);
+ return -ENOSPC;
+ }
+ leaf->lf_dist = cpu_to_be32(dist);
+ oleaf->lf_next = cpu_to_be64(bh->b_blocknr);
+ brelse(bh);
+ brelse(obh);
+
+ error = gfs2_meta_inode_buffer(ip, &bh);
+ if (error)
+ return error;
+ gfs2_trans_add_meta(ip->i_gl, bh);
+ gfs2_add_inode_blocks(&ip->i_inode, 1);
+ gfs2_dinode_out(ip, bh->b_data);
+ brelse(bh);
+ return 0;
+}
+
+static u16 gfs2_inode_ra_len(const struct gfs2_inode *ip)
+{
+ u64 where = ip->i_no_addr + 1;
+ if (ip->i_eattr == where)
+ return 1;
+ return 0;
+}
+
+/**
+ * gfs2_dir_add - Add new filename into directory
+ * @inode: The directory inode
+ * @name: The new name
+ * @nip: The GFS2 inode to be linked in to the directory
+ * @da: The directory addition info
+ *
+ * If the call to gfs2_diradd_alloc_required resulted in there being
+ * no need to allocate any new directory blocks, then it will contain
+ * a pointer to the directory entry and the bh in which it resides. We
+ * can use that without having to repeat the search. If there was no
+ * free space, then we must now create more space.
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+int gfs2_dir_add(struct inode *inode, const struct qstr *name,
+ const struct gfs2_inode *nip, struct gfs2_diradd *da)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct buffer_head *bh = da->bh;
+ struct gfs2_dirent *dent = da->dent;
+ struct timespec tv;
+ struct gfs2_leaf *leaf;
+ int error;
+
+ while(1) {
+ if (da->bh == NULL) {
+ dent = gfs2_dirent_search(inode, name,
+ gfs2_dirent_find_space, &bh);
+ }
+ if (dent) {
+ if (IS_ERR(dent))
+ return PTR_ERR(dent);
+ dent = gfs2_init_dirent(inode, dent, name, bh);
+ gfs2_inum_out(nip, dent);
+ dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
+ dent->de_rahead = cpu_to_be16(gfs2_inode_ra_len(nip));
+ tv = current_time(&ip->i_inode);
+ if (ip->i_diskflags & GFS2_DIF_EXHASH) {
+ leaf = (struct gfs2_leaf *)bh->b_data;
+ be16_add_cpu(&leaf->lf_entries, 1);
+ leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
+ leaf->lf_sec = cpu_to_be64(tv.tv_sec);
+ }
+ da->dent = NULL;
+ da->bh = NULL;
+ brelse(bh);
+ ip->i_entries++;
+ ip->i_inode.i_mtime = ip->i_inode.i_ctime = tv;
+ if (S_ISDIR(nip->i_inode.i_mode))
+ inc_nlink(&ip->i_inode);
+ mark_inode_dirty(inode);
+ error = 0;
+ break;
+ }
+ if (!(ip->i_diskflags & GFS2_DIF_EXHASH)) {
+ error = dir_make_exhash(inode);
+ if (error)
+ break;
+ continue;
+ }
+ error = dir_split_leaf(inode, name);
+ if (error == 0)
+ continue;
+ if (error < 0)
+ break;
+ if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
+ error = dir_double_exhash(ip);
+ if (error)
+ break;
+ error = dir_split_leaf(inode, name);
+ if (error < 0)
+ break;
+ if (error == 0)
+ continue;
+ }
+ error = dir_new_leaf(inode, name);
+ if (!error)
+ continue;
+ error = -ENOSPC;
+ break;
+ }
+ return error;
+}
+
+
+/**
+ * gfs2_dir_del - Delete a directory entry
+ * @dip: The GFS2 inode
+ * @filename: The filename
+ *
+ * Returns: 0 on success, error code on failure
+ */
+
+int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
+{
+ const struct qstr *name = &dentry->d_name;
+ struct gfs2_dirent *dent, *prev = NULL;
+ struct buffer_head *bh;
+ struct timespec tv = current_time(&dip->i_inode);
+
+ /* Returns _either_ the entry (if its first in block) or the
+ previous entry otherwise */
+ dent = gfs2_dirent_search(&dip->i_inode, name, gfs2_dirent_prev, &bh);
+ if (!dent) {
+ gfs2_consist_inode(dip);
+ return -EIO;
+ }
+ if (IS_ERR(dent)) {
+ gfs2_consist_inode(dip);
+ return PTR_ERR(dent);
+ }
+ /* If not first in block, adjust pointers accordingly */
+ if (gfs2_dirent_find(dent, name, NULL) == 0) {
+ prev = dent;
+ dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
+ }
+
+ dirent_del(dip, bh, prev, dent);
+ if (dip->i_diskflags & GFS2_DIF_EXHASH) {
+ struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
+ u16 entries = be16_to_cpu(leaf->lf_entries);
+ if (!entries)
+ gfs2_consist_inode(dip);
+ leaf->lf_entries = cpu_to_be16(--entries);
+ leaf->lf_nsec = cpu_to_be32(tv.tv_nsec);
+ leaf->lf_sec = cpu_to_be64(tv.tv_sec);
+ }
+ brelse(bh);
+
+ if (!dip->i_entries)
+ gfs2_consist_inode(dip);
+ dip->i_entries--;
+ dip->i_inode.i_mtime = dip->i_inode.i_ctime = tv;
+ if (d_is_dir(dentry))
+ drop_nlink(&dip->i_inode);
+ mark_inode_dirty(&dip->i_inode);
+
+ return 0;
+}
+
+/**
+ * gfs2_dir_mvino - Change inode number of directory entry
+ * @dip: The GFS2 inode
+ * @filename:
+ * @new_inode:
+ *
+ * This routine changes the inode number of a directory entry. It's used
+ * by rename to change ".." when a directory is moved.
+ * Assumes a glock is held on dvp.
+ *
+ * Returns: errno
+ */
+
+int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
+ const struct gfs2_inode *nip, unsigned int new_type)
+{
+ struct buffer_head *bh;
+ struct gfs2_dirent *dent;
+ int error;
+
+ dent = gfs2_dirent_search(&dip->i_inode, filename, gfs2_dirent_find, &bh);
+ if (!dent) {
+ gfs2_consist_inode(dip);
+ return -EIO;
+ }
+ if (IS_ERR(dent))
+ return PTR_ERR(dent);
+
+ gfs2_trans_add_meta(dip->i_gl, bh);
+ gfs2_inum_out(nip, dent);
+ dent->de_type = cpu_to_be16(new_type);
+
+ if (dip->i_diskflags & GFS2_DIF_EXHASH) {
+ brelse(bh);
+ error = gfs2_meta_inode_buffer(dip, &bh);
+ if (error)
+ return error;
+ gfs2_trans_add_meta(dip->i_gl, bh);
+ }
+
+ dip->i_inode.i_mtime = dip->i_inode.i_ctime = current_time(&dip->i_inode);
+ gfs2_dinode_out(dip, bh->b_data);
+ brelse(bh);
+ return 0;
+}
+
+/**
+ * leaf_dealloc - Deallocate a directory leaf
+ * @dip: the directory
+ * @index: the hash table offset in the directory
+ * @len: the number of pointers to this leaf
+ * @leaf_no: the leaf number
+ * @leaf_bh: buffer_head for the starting leaf
+ * last_dealloc: 1 if this is the final dealloc for the leaf, else 0
+ *
+ * Returns: errno
+ */
+
+static int leaf_dealloc(struct gfs2_inode *dip, u32 index, u32 len,
+ u64 leaf_no, struct buffer_head *leaf_bh,
+ int last_dealloc)
+{
+ struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
+ struct gfs2_leaf *tmp_leaf;
+ struct gfs2_rgrp_list rlist;
+ struct buffer_head *bh, *dibh;
+ u64 blk, nblk;
+ unsigned int rg_blocks = 0, l_blocks = 0;
+ char *ht;
+ unsigned int x, size = len * sizeof(u64);
+ int error;
+
+ error = gfs2_rindex_update(sdp);
+ if (error)
+ return error;
+
+ memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
+
+ ht = kzalloc(size, GFP_NOFS | __GFP_NOWARN);
+ if (ht == NULL)
+ ht = __vmalloc(size, GFP_NOFS | __GFP_NOWARN | __GFP_ZERO,
+ PAGE_KERNEL);
+ if (!ht)
+ return -ENOMEM;
+
+ error = gfs2_quota_hold(dip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
+ if (error)
+ goto out;
+
+ /* Count the number of leaves */
+ bh = leaf_bh;
+
+ for (blk = leaf_no; blk; blk = nblk) {
+ if (blk != leaf_no) {
+ error = get_leaf(dip, blk, &bh);
+ if (error)
+ goto out_rlist;
+ }
+ tmp_leaf = (struct gfs2_leaf *)bh->b_data;
+ nblk = be64_to_cpu(tmp_leaf->lf_next);
+ if (blk != leaf_no)
+ brelse(bh);
+
+ gfs2_rlist_add(dip, &rlist, blk);
+ l_blocks++;
+ }
+
+ gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);
+
+ for (x = 0; x < rlist.rl_rgrps; x++) {
+ struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(rlist.rl_ghs[x].gh_gl);
+
+ rg_blocks += rgd->rd_length;
+ }
+
+ error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
+ if (error)
+ goto out_rlist;
+
+ error = gfs2_trans_begin(sdp,
+ rg_blocks + (DIV_ROUND_UP(size, sdp->sd_jbsize) + 1) +
+ RES_DINODE + RES_STATFS + RES_QUOTA, l_blocks);
+ if (error)
+ goto out_rg_gunlock;
+
+ bh = leaf_bh;
+
+ for (blk = leaf_no; blk; blk = nblk) {
+ if (blk != leaf_no) {
+ error = get_leaf(dip, blk, &bh);
+ if (error)
+ goto out_end_trans;
+ }
+ tmp_leaf = (struct gfs2_leaf *)bh->b_data;
+ nblk = be64_to_cpu(tmp_leaf->lf_next);
+ if (blk != leaf_no)
+ brelse(bh);
+
+ gfs2_free_meta(dip, blk, 1);
+ gfs2_add_inode_blocks(&dip->i_inode, -1);
+ }
+
+ error = gfs2_dir_write_data(dip, ht, index * sizeof(u64), size);
+ if (error != size) {
+ if (error >= 0)
+ error = -EIO;
+ goto out_end_trans;
+ }
+
+ error = gfs2_meta_inode_buffer(dip, &dibh);
+ if (error)
+ goto out_end_trans;
+
+ gfs2_trans_add_meta(dip->i_gl, dibh);
+ /* On the last dealloc, make this a regular file in case we crash.
+ (We don't want to free these blocks a second time.) */
+ if (last_dealloc)
+ dip->i_inode.i_mode = S_IFREG;
+ gfs2_dinode_out(dip, dibh->b_data);
+ brelse(dibh);
+
+out_end_trans:
+ gfs2_trans_end(sdp);
+out_rg_gunlock:
+ gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
+out_rlist:
+ gfs2_rlist_free(&rlist);
+ gfs2_quota_unhold(dip);
+out:
+ kvfree(ht);
+ return error;
+}
+
+/**
+ * gfs2_dir_exhash_dealloc - free all the leaf blocks in a directory
+ * @dip: the directory
+ *
+ * Dealloc all on-disk directory leaves to FREEMETA state
+ * Change on-disk inode type to "regular file"
+ *
+ * Returns: errno
+ */
+
+int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip)
+{
+ struct buffer_head *bh;
+ struct gfs2_leaf *leaf;
+ u32 hsize, len;
+ u32 index = 0, next_index;
+ __be64 *lp;
+ u64 leaf_no;
+ int error = 0, last;
+
+ hsize = BIT(dip->i_depth);
+
+ lp = gfs2_dir_get_hash_table(dip);
+ if (IS_ERR(lp))
+ return PTR_ERR(lp);
+
+ while (index < hsize) {
+ leaf_no = be64_to_cpu(lp[index]);
+ if (leaf_no) {
+ error = get_leaf(dip, leaf_no, &bh);
+ if (error)
+ goto out;
+ leaf = (struct gfs2_leaf *)bh->b_data;
+ len = BIT(dip->i_depth - be16_to_cpu(leaf->lf_depth));
+
+ next_index = (index & ~(len - 1)) + len;
+ last = ((next_index >= hsize) ? 1 : 0);
+ error = leaf_dealloc(dip, index, len, leaf_no, bh,
+ last);
+ brelse(bh);
+ if (error)
+ goto out;
+ index = next_index;
+ } else
+ index++;
+ }
+
+ if (index != hsize) {
+ gfs2_consist_inode(dip);
+ error = -EIO;
+ }
+
+out:
+
+ return error;
+}
+
+/**
+ * gfs2_diradd_alloc_required - find if adding entry will require an allocation
+ * @ip: the file being written to
+ * @filname: the filename that's going to be added
+ * @da: The structure to return dir alloc info
+ *
+ * Returns: 0 if ok, -ve on error
+ */
+
+int gfs2_diradd_alloc_required(struct inode *inode, const struct qstr *name,
+ struct gfs2_diradd *da)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ const unsigned int extra = sizeof(struct gfs2_dinode) - sizeof(struct gfs2_leaf);
+ struct gfs2_dirent *dent;
+ struct buffer_head *bh;
+
+ da->nr_blocks = 0;
+ da->bh = NULL;
+ da->dent = NULL;
+
+ dent = gfs2_dirent_search(inode, name, gfs2_dirent_find_space, &bh);
+ if (!dent) {
+ da->nr_blocks = sdp->sd_max_dirres;
+ if (!(ip->i_diskflags & GFS2_DIF_EXHASH) &&
+ (GFS2_DIRENT_SIZE(name->len) < extra))
+ da->nr_blocks = 1;
+ return 0;
+ }
+ if (IS_ERR(dent))
+ return PTR_ERR(dent);
+
+ if (da->save_loc) {
+ da->bh = bh;
+ da->dent = dent;
+ } else {
+ brelse(bh);
+ }
+ return 0;
+}
+