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ext2: propagate errors up to ext2_find_entry()'s callers

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The same to commit <36de928641ee4> (ext4: propagate errors up to
ext4_find_entry()'s callers') in ext4, also return error instead of NULL
pointer in case of some error happens in ext2_find_entry() (e.g. -ENOMEM
or -EIO). This could avoid a negative dentry cache entry installed even
it failed to read directory block due to IO error.

Link: https://lore.kernel.org/r/20200608034043.10451-1-yi.zhang@huawei.com
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
zhangyi (F) 2020-06-08 11:40:42 +08:00 committed by Jan Kara
parent 1fcbcf06e4
commit b4962091a5
3 changed files with 54 additions and 34 deletions
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53
fs/ext2/dir.c
View file

@ -348,7 +348,6 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
struct page *page = NULL;
struct ext2_inode_info *ei = EXT2_I(dir);
ext2_dirent * de;
int dir_has_error = 0;
if (npages == 0)
goto out;
@ -362,25 +361,25 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
n = start;
do {
char *kaddr;
page = ext2_get_page(dir, n, dir_has_error);
if (!IS_ERR(page)) {
kaddr = page_address(page);
de = (ext2_dirent *) kaddr;
kaddr += ext2_last_byte(dir, n) - reclen;
while ((char *) de <= kaddr) {
if (de->rec_len == 0) {
ext2_error(dir->i_sb, __func__,
"zero-length directory entry");
ext2_put_page(page);
goto out;
}
if (ext2_match (namelen, name, de))
goto found;
de = ext2_next_entry(de);
page = ext2_get_page(dir, n, 0);
if (IS_ERR(page))
return ERR_CAST(page);
kaddr = page_address(page);
de = (ext2_dirent *) kaddr;
kaddr += ext2_last_byte(dir, n) - reclen;
while ((char *) de <= kaddr) {
if (de->rec_len == 0) {
ext2_error(dir->i_sb, __func__,
"zero-length directory entry");
ext2_put_page(page);
goto out;
}
ext2_put_page(page);
} else
dir_has_error = 1;
if (ext2_match(namelen, name, de))
goto found;
de = ext2_next_entry(de);
}
ext2_put_page(page);
if (++n >= npages)
n = 0;
@ -414,18 +413,18 @@ struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
return de;
}
ino_t ext2_inode_by_name(struct inode *dir, const struct qstr *child)
int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino)
{
ino_t res = 0;
struct ext2_dir_entry_2 *de;
struct page *page;
de = ext2_find_entry (dir, child, &page);
if (de) {
res = le32_to_cpu(de->inode);
ext2_put_page(page);
}
return res;
de = ext2_find_entry(dir, child, &page);
if (IS_ERR_OR_NULL(de))
return PTR_ERR(de);
*ino = le32_to_cpu(de->inode);
ext2_put_page(page);
return 0;
}
static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)

3
fs/ext2/ext2.h
View file

@ -738,7 +738,8 @@ extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_wind
/* dir.c */
extern int ext2_add_link (struct dentry *, struct inode *);
extern ino_t ext2_inode_by_name(struct inode *, const struct qstr *);
extern int ext2_inode_by_name(struct inode *dir,
const struct qstr *child, ino_t *ino);
extern int ext2_make_empty(struct inode *, struct inode *);
extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,const struct qstr *, struct page **);
extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);

32
fs/ext2/namei.c
View file

@ -56,12 +56,15 @@ static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
{
struct inode * inode;
ino_t ino;
ino_t ino = 0;
int res;
if (dentry->d_name.len > EXT2_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ino = ext2_inode_by_name(dir, &dentry->d_name);
res = ext2_inode_by_name(dir, &dentry->d_name, &ino);
if (res)
return ERR_PTR(res);
inode = NULL;
if (ino) {
inode = ext2_iget(dir->i_sb, ino);
@ -78,7 +81,12 @@ static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, uns
struct dentry *ext2_get_parent(struct dentry *child)
{
struct qstr dotdot = QSTR_INIT("..", 2);
unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
ino_t ino = 0;
int res;
res = ext2_inode_by_name(d_inode(child), &dotdot, &ino);
if (res)
return ERR_PTR(res);
if (!ino)
return ERR_PTR(-ENOENT);
return d_obtain_alias(ext2_iget(child->d_sb, ino));
@ -274,7 +282,11 @@ static int ext2_unlink(struct inode * dir, struct dentry *dentry)
if (err)
goto out;
de = ext2_find_entry (dir, &dentry->d_name, &page);
de = ext2_find_entry(dir, &dentry->d_name, &page);
if (IS_ERR(de)) {
err = PTR_ERR(de);
goto out;
}
if (!de) {
err = -ENOENT;
goto out;
@ -330,7 +342,11 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
if (err)
goto out;
old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
old_de = ext2_find_entry(old_dir, &old_dentry->d_name, &old_page);
if (IS_ERR(old_de)) {
err = PTR_ERR(old_de);
goto out;
}
if (!old_de) {
err = -ENOENT;
goto out;
@ -352,7 +368,11 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
goto out_dir;
err = -ENOENT;
new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
new_de = ext2_find_entry(new_dir, &new_dentry->d_name, &new_page);
if (IS_ERR(new_de)) {
err = PTR_ERR(new_de);
goto out_dir;
}
if (!new_de)
goto out_dir;
ext2_set_link(new_dir, new_de, new_page, old_inode, 1);