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Diffstat (limited to 'fs/ext4/namei.c')
-rw-r--r--fs/ext4/namei.c96
1 files changed, 68 insertions, 28 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 3c3757ee11f0..339ede11896a 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -79,8 +79,18 @@ static struct buffer_head *ext4_append(handle_t *handle,
static int ext4_dx_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent);
+/*
+ * Hints to ext4_read_dirblock regarding whether we expect a directory
+ * block being read to be an index block, or a block containing
+ * directory entries (and if the latter, whether it was found via a
+ * logical block in an htree index block). This is used to control
+ * what sort of sanity checkinig ext4_read_dirblock() will do on the
+ * directory block read from the storage device. EITHER will means
+ * the caller doesn't know what kind of directory block will be read,
+ * so no specific verification will be done.
+ */
typedef enum {
- EITHER, INDEX, DIRENT
+ EITHER, INDEX, DIRENT, DIRENT_HTREE
} dirblock_type_t;
#define ext4_read_dirblock(inode, block, type) \
@@ -106,11 +116,14 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
return bh;
}
- if (!bh) {
+ if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
ext4_error_inode(inode, func, line, block,
- "Directory hole found");
+ "Directory hole found for htree %s block",
+ (type == INDEX) ? "index" : "leaf");
return ERR_PTR(-EFSCORRUPTED);
}
+ if (!bh)
+ return NULL;
dirent = (struct ext4_dir_entry *) bh->b_data;
/* Determine whether or not we have an index block */
if (is_dx(inode)) {
@@ -960,7 +973,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
(unsigned long)block));
- bh = ext4_read_dirblock(dir, block, DIRENT);
+ bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
if (IS_ERR(bh))
return PTR_ERR(bh);
@@ -1432,6 +1445,7 @@ restart:
/*
* We deal with the read-ahead logic here.
*/
+ cond_resched();
if (ra_ptr >= ra_max) {
/* Refill the readahead buffer */
ra_ptr = 0;
@@ -1537,7 +1551,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
return (struct buffer_head *) frame;
do {
block = dx_get_block(frame->at);
- bh = ext4_read_dirblock(dir, block, DIRENT);
+ bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
if (IS_ERR(bh))
goto errout;
@@ -2135,6 +2149,13 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
retval = ext4_dx_add_entry(handle, &fname, dir, inode);
if (!retval || (retval != ERR_BAD_DX_DIR))
goto out;
+ /* Can we just ignore htree data? */
+ if (ext4_has_metadata_csum(sb)) {
+ EXT4_ERROR_INODE(dir,
+ "Directory has corrupted htree index.");
+ retval = -EFSCORRUPTED;
+ goto out;
+ }
ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
dx_fallback++;
ext4_mark_inode_dirty(handle, dir);
@@ -2142,6 +2163,11 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
blocks = dir->i_size >> sb->s_blocksize_bits;
for (block = 0; block < blocks; block++) {
bh = ext4_read_dirblock(dir, block, DIRENT);
+ if (bh == NULL) {
+ bh = ext4_bread(handle, dir, block,
+ EXT4_GET_BLOCKS_CREATE);
+ goto add_to_new_block;
+ }
if (IS_ERR(bh)) {
retval = PTR_ERR(bh);
bh = NULL;
@@ -2162,6 +2188,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
brelse(bh);
}
bh = ext4_append(handle, dir, &block);
+add_to_new_block:
if (IS_ERR(bh)) {
retval = PTR_ERR(bh);
bh = NULL;
@@ -2203,7 +2230,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
return PTR_ERR(frame);
entries = frame->entries;
at = frame->at;
- bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
+ bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
bh = NULL;
@@ -2702,7 +2729,7 @@ bool ext4_empty_dir(struct inode *inode)
{
unsigned int offset;
struct buffer_head *bh;
- struct ext4_dir_entry_2 *de, *de1;
+ struct ext4_dir_entry_2 *de;
struct super_block *sb;
if (ext4_has_inline_data(inode)) {
@@ -2719,36 +2746,48 @@ bool ext4_empty_dir(struct inode *inode)
EXT4_ERROR_INODE(inode, "invalid size");
return true;
}
- bh = ext4_read_dirblock(inode, 0, EITHER);
+ /* The first directory block must not be a hole,
+ * so treat it as DIRENT_HTREE
+ */
+ bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
if (IS_ERR(bh))
return true;
de = (struct ext4_dir_entry_2 *) bh->b_data;
- de1 = ext4_next_entry(de, sb->s_blocksize);
- if (le32_to_cpu(de->inode) != inode->i_ino ||
- le32_to_cpu(de1->inode) == 0 ||
- strcmp(".", de->name) || strcmp("..", de1->name)) {
- ext4_warning_inode(inode, "directory missing '.' and/or '..'");
+ if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
+ 0) ||
+ le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
+ ext4_warning_inode(inode, "directory missing '.'");
brelse(bh);
return true;
}
- offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
- ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
- de = ext4_next_entry(de1, sb->s_blocksize);
+ offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
+ de = ext4_next_entry(de, sb->s_blocksize);
+ if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
+ offset) ||
+ le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
+ ext4_warning_inode(inode, "directory missing '..'");
+ brelse(bh);
+ return true;
+ }
+ offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
while (offset < inode->i_size) {
- if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
+ if (!(offset & (sb->s_blocksize - 1))) {
unsigned int lblock;
brelse(bh);
lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
bh = ext4_read_dirblock(inode, lblock, EITHER);
+ if (bh == NULL) {
+ offset += sb->s_blocksize;
+ continue;
+ }
if (IS_ERR(bh))
return true;
- de = (struct ext4_dir_entry_2 *) bh->b_data;
}
+ de = (struct ext4_dir_entry_2 *) (bh->b_data +
+ (offset & (sb->s_blocksize - 1)));
if (ext4_check_dir_entry(inode, NULL, de, bh,
bh->b_data, bh->b_size, offset)) {
- de = (struct ext4_dir_entry_2 *)(bh->b_data +
- sb->s_blocksize);
offset = (offset | (sb->s_blocksize - 1)) + 1;
continue;
}
@@ -2757,7 +2796,6 @@ bool ext4_empty_dir(struct inode *inode)
return false;
}
offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
- de = ext4_next_entry(de, sb->s_blocksize);
}
brelse(bh);
return true;
@@ -3052,18 +3090,17 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
if (IS_DIRSYNC(dir))
ext4_handle_sync(handle);
- if (inode->i_nlink == 0) {
- ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
- dentry->d_name.len, dentry->d_name.name);
- set_nlink(inode, 1);
- }
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_unlink;
dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
- drop_nlink(inode);
+ if (inode->i_nlink == 0)
+ ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
+ dentry->d_name.len, dentry->d_name.name);
+ else
+ drop_nlink(inode);
if (!inode->i_nlink)
ext4_orphan_add(handle, inode);
inode->i_ctime = ext4_current_time(inode);
@@ -3302,7 +3339,10 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
struct buffer_head *bh;
if (!ext4_has_inline_data(inode)) {
- bh = ext4_read_dirblock(inode, 0, EITHER);
+ /* The first directory block must not be a hole, so
+ * treat it as DIRENT_HTREE
+ */
+ bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
if (IS_ERR(bh)) {
*retval = PTR_ERR(bh);
return NULL;
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-14 20:54:37 +0000