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Diffstat (limited to 'fs/ext4/namei.c')
-rw-r--r--fs/ext4/namei.c73
1 files changed, 65 insertions, 8 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index da224974af78..5fdb862e71c4 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -140,7 +140,8 @@ struct dx_frame
struct dx_map_entry
{
u32 hash;
- u32 offs;
+ u16 offs;
+ u16 size;
};
#ifdef CONFIG_EXT4_INDEX
@@ -379,13 +380,28 @@ dx_probe(struct dentry *dentry, struct inode *dir,
entries = (struct dx_entry *) (((char *)&root->info) +
root->info.info_length);
- assert(dx_get_limit(entries) == dx_root_limit(dir,
- root->info.info_length));
+
+ if (dx_get_limit(entries) != dx_root_limit(dir,
+ root->info.info_length)) {
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "dx entry: limit != root limit");
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail;
+ }
+
dxtrace (printk("Look up %x", hash));
while (1)
{
count = dx_get_count(entries);
- assert (count && count <= dx_get_limit(entries));
+ if (!count || count > dx_get_limit(entries)) {
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "dx entry: no count or count > limit");
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail2;
+ }
+
p = entries + 1;
q = entries + count - 1;
while (p <= q)
@@ -423,8 +439,15 @@ dx_probe(struct dentry *dentry, struct inode *dir,
if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
goto fail2;
at = entries = ((struct dx_node *) bh->b_data)->entries;
- assert (dx_get_limit(entries) == dx_node_limit (dir));
+ if (dx_get_limit(entries) != dx_node_limit (dir)) {
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "dx entry: limit != node limit");
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail2;
+ }
frame++;
+ frame->bh = NULL;
}
fail2:
while (frame >= frame_in) {
@@ -432,6 +455,10 @@ fail2:
frame--;
}
fail:
+ if (*err == ERR_BAD_DX_DIR)
+ ext4_warning(dir->i_sb, __FUNCTION__,
+ "Corrupt dir inode %ld, running e2fsck is "
+ "recommended.", dir->i_ino);
return NULL;
}
@@ -671,6 +698,10 @@ errout:
* Directory block splitting, compacting
*/
+/*
+ * Create map of hash values, offsets, and sizes, stored at end of block.
+ * Returns number of entries mapped.
+ */
static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
struct dx_hash_info *hinfo, struct dx_map_entry *map_tail)
{
@@ -684,7 +715,8 @@ static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
ext4fs_dirhash(de->name, de->name_len, &h);
map_tail--;
map_tail->hash = h.hash;
- map_tail->offs = (u32) ((char *) de - base);
+ map_tail->offs = (u16) ((char *) de - base);
+ map_tail->size = le16_to_cpu(de->rec_len);
count++;
cond_resched();
}
@@ -694,6 +726,7 @@ static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
return count;
}
+/* Sort map by hash value */
static void dx_sort_map (struct dx_map_entry *map, unsigned count)
{
struct dx_map_entry *p, *q, *top = map + count - 1;
@@ -1089,6 +1122,10 @@ static inline void ext4_set_de_type(struct super_block *sb,
}
#ifdef CONFIG_EXT4_INDEX
+/*
+ * Move count entries from end of map between two memory locations.
+ * Returns pointer to last entry moved.
+ */
static struct ext4_dir_entry_2 *
dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
{
@@ -1107,6 +1144,10 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
return (struct ext4_dir_entry_2 *) (to - rec_len);
}
+/*
+ * Compact each dir entry in the range to the minimal rec_len.
+ * Returns pointer to last entry in range.
+ */
static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
{
struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
@@ -1129,6 +1170,11 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
return prev;
}
+/*
+ * Split a full leaf block to make room for a new dir entry.
+ * Allocate a new block, and move entries so that they are approx. equally full.
+ * Returns pointer to de in block into which the new entry will be inserted.
+ */
static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
struct buffer_head **bh,struct dx_frame *frame,
struct dx_hash_info *hinfo, int *error)
@@ -1140,7 +1186,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
u32 hash2;
struct dx_map_entry *map;
char *data1 = (*bh)->b_data, *data2;
- unsigned split;
+ unsigned split, move, size, i;
struct ext4_dir_entry_2 *de = NULL, *de2;
int err = 0;
@@ -1168,8 +1214,19 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
count = dx_make_map ((struct ext4_dir_entry_2 *) data1,
blocksize, hinfo, map);
map -= count;
- split = count/2; // need to adjust to actual middle
dx_sort_map (map, count);
+ /* Split the existing block in the middle, size-wise */
+ size = 0;
+ move = 0;
+ for (i = count-1; i >= 0; i--) {
+ /* is more than half of this entry in 2nd half of the block? */
+ if (size + map[i].size/2 > blocksize/2)
+ break;
+ size += map[i].size;
+ move++;
+ }
+ /* map index at which we will split */
+ split = count - move;
hash2 = map[split].hash;
continued = hash2 == map[split - 1].hash;
dxtrace(printk("Split block %i at %x, %i/%i\n",

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