* [PATCH] fat: roll back the new entry when create/mkdir fails to build the inode
@ 2026-10-12 6:43 zhoumin
2026-10-12 9:24 ` OGAWA Hirofumi
0 siblings, 1 reply; 3+ messages in thread
From: zhoumin @ 2026-10-12 6:43 UTC (permalink / raw)
To: hirofumi; +Cc: linux-kernel, teczm
vfat_create(), vfat_mkdir(), msdos_create() and msdos_mkdir() add the
on-disk entry before calling fat_build_inode() to set up the VFS
inode. If fat_build_inode() fails, the error is returned but the
entry stays on disk and the file or directory shows up after remount.
Remove the entry in that case. For mkdir, also free the directory
cluster and decrement the parent's link count.
Signed-off-by: zhoumin <teczm@foxmail.com>
---
fs/fat/namei_msdos.c | 19 ++++++++++++++-----
fs/fat/namei_vfat.c | 19 ++++++++++++++-----
2 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index d46d1a3851f2..a0d1af5b8a5b 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -271,7 +271,7 @@ static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
struct fat_slot_info sinfo;
struct timespec64 ts;
unsigned char msdos_name[MSDOS_NAME];
- int err, is_hid;
+ int err, err2, is_hid;
mutex_lock(&MSDOS_SB(sb)->s_lock);
@@ -292,11 +292,15 @@ static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
if (err)
goto out;
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2)
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
goto out;
}
+ brelse(sinfo.bh);
fat_truncate_time(inode, &ts, FAT_UPDATE_ATIME | FAT_UPDATE_CMTIME);
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
@@ -353,7 +357,7 @@ static struct dentry *msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct inode *inode;
unsigned char msdos_name[MSDOS_NAME];
struct timespec64 ts;
- int err, is_hid, cluster;
+ int err, err2, is_hid, cluster;
mutex_lock(&MSDOS_SB(sb)->s_lock);
@@ -381,12 +385,17 @@ static struct dentry *msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
inc_nlink(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
- /* the directory was completed, just return a error */
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2)
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
+ drop_nlink(dir);
+ fat_free_clusters(dir, cluster);
goto out;
}
+ brelse(sinfo.bh);
set_nlink(inode, 2);
fat_truncate_time(inode, &ts, FAT_UPDATE_ATIME | FAT_UPDATE_CMTIME);
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index da3e89c0b16a..31d83de5beaa 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -760,7 +760,7 @@ static int vfat_create(struct mnt_idmap *idmap, struct inode *dir,
struct inode *inode;
struct fat_slot_info sinfo;
struct timespec64 ts;
- int err;
+ int err, err2;
mutex_lock(&MSDOS_SB(sb)->s_lock);
@@ -771,11 +771,15 @@ static int vfat_create(struct mnt_idmap *idmap, struct inode *dir,
inode_inc_iversion(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2)
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
goto out;
}
+ brelse(sinfo.bh);
inode_inc_iversion(inode);
d_instantiate(dentry, inode);
@@ -853,7 +857,7 @@ static struct dentry *vfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct inode *inode;
struct fat_slot_info sinfo;
struct timespec64 ts;
- int err, cluster;
+ int err, err2, cluster;
mutex_lock(&MSDOS_SB(sb)->s_lock);
@@ -870,12 +874,17 @@ static struct dentry *vfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
inc_nlink(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
- /* the directory was completed, just return a error */
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2)
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
+ drop_nlink(dir);
+ fat_free_clusters(dir, cluster);
goto out;
}
+ brelse(sinfo.bh);
inode_inc_iversion(inode);
set_nlink(inode, 2);
--
2.53.0
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] fat: roll back the new entry when create/mkdir fails to build the inode
2026-10-12 6:43 [PATCH] fat: roll back the new entry when create/mkdir fails to build the inode zhoumin
@ 2026-10-12 9:24 ` OGAWA Hirofumi
2026-10-12 13:20 ` [PATCH v2] " zhoumin
0 siblings, 1 reply; 3+ messages in thread
From: OGAWA Hirofumi @ 2026-10-12 9:24 UTC (permalink / raw)
To: zhoumin; +Cc: linux-kernel
zhoumin <teczm@foxmail.com> writes:
> vfat_create(), vfat_mkdir(), msdos_create() and msdos_mkdir() add the
> on-disk entry before calling fat_build_inode() to set up the VFS
> inode. If fat_build_inode() fails, the error is returned but the
> entry stays on disk and the file or directory shows up after remount.
>
> Remove the entry in that case. For mkdir, also free the directory
> cluster and decrement the parent's link count.
>
> Signed-off-by: zhoumin <teczm@foxmail.com>
> ---
> fs/fat/namei_msdos.c | 19 ++++++++++++++-----
> fs/fat/namei_vfat.c | 19 ++++++++++++++-----
> 2 files changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
> index d46d1a3851f2..a0d1af5b8a5b 100644
> --- a/fs/fat/namei_msdos.c
> +++ b/fs/fat/namei_msdos.c
> @@ -271,7 +271,7 @@ static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
> struct fat_slot_info sinfo;
> struct timespec64 ts;
> unsigned char msdos_name[MSDOS_NAME];
> - int err, is_hid;
> + int err, err2, is_hid;
>
> mutex_lock(&MSDOS_SB(sb)->s_lock);
>
> @@ -292,11 +292,15 @@ static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
> if (err)
> goto out;
> inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
> - brelse(sinfo.bh);
> if (IS_ERR(inode)) {
> err = PTR_ERR(inode);
> + err2 = fat_remove_entries(dir, &sinfo);
> + if (err2)
> + fat_msg(sb, KERN_WARNING,
> + "failed to roll back new entry (%d)", err2);
int err2 = fat_remove_entries(dir, &sinfo);
if (err2)
fat_msg(sb, KERN_WARNING,
"failed to roll back new entry (%d)", err2);
err = PTR_ERR(inode);
is better? (and other 3 parts are same).
> goto out;
> }
> + brelse(sinfo.bh);
> fat_truncate_time(inode, &ts, FAT_UPDATE_ATIME | FAT_UPDATE_CMTIME);
> /* timestamp is already written, so mark_inode_dirty() is unneeded. */
>
> @@ -353,7 +357,7 @@ static struct dentry *msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> struct inode *inode;
> unsigned char msdos_name[MSDOS_NAME];
> struct timespec64 ts;
> - int err, is_hid, cluster;
> + int err, err2, is_hid, cluster;
>
> mutex_lock(&MSDOS_SB(sb)->s_lock);
>
> @@ -381,12 +385,17 @@ static struct dentry *msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> inc_nlink(dir);
>
> inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
> - brelse(sinfo.bh);
> if (IS_ERR(inode)) {
> err = PTR_ERR(inode);
> - /* the directory was completed, just return a error */
> + err2 = fat_remove_entries(dir, &sinfo);
> + if (err2)
> + fat_msg(sb, KERN_WARNING,
> + "failed to roll back new entry (%d)", err2);
> + drop_nlink(dir);
ditto
> + fat_free_clusters(dir, cluster);
Maybe "goto out_free" instead of fat_free_cluster()?
> goto out;
> }
> + brelse(sinfo.bh);
> set_nlink(inode, 2);
> fat_truncate_time(inode, &ts, FAT_UPDATE_ATIME | FAT_UPDATE_CMTIME);
> /* timestamp is already written, so mark_inode_dirty() is unneeded. */
> diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
> index da3e89c0b16a..31d83de5beaa 100644
> --- a/fs/fat/namei_vfat.c
> +++ b/fs/fat/namei_vfat.c
> @@ -760,7 +760,7 @@ static int vfat_create(struct mnt_idmap *idmap, struct inode *dir,
> struct inode *inode;
> struct fat_slot_info sinfo;
> struct timespec64 ts;
> - int err;
> + int err, err2;
>
> mutex_lock(&MSDOS_SB(sb)->s_lock);
>
> @@ -771,11 +771,15 @@ static int vfat_create(struct mnt_idmap *idmap, struct inode *dir,
> inode_inc_iversion(dir);
>
> inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
> - brelse(sinfo.bh);
> if (IS_ERR(inode)) {
> err = PTR_ERR(inode);
> + err2 = fat_remove_entries(dir, &sinfo);
> + if (err2)
> + fat_msg(sb, KERN_WARNING,
> + "failed to roll back new entry (%d)", err2);
ditto
> goto out;
> }
> + brelse(sinfo.bh);
> inode_inc_iversion(inode);
>
> d_instantiate(dentry, inode);
> @@ -853,7 +857,7 @@ static struct dentry *vfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> struct inode *inode;
> struct fat_slot_info sinfo;
> struct timespec64 ts;
> - int err, cluster;
> + int err, err2, cluster;
>
> mutex_lock(&MSDOS_SB(sb)->s_lock);
>
> @@ -870,12 +874,17 @@ static struct dentry *vfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> inc_nlink(dir);
>
> inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
> - brelse(sinfo.bh);
> if (IS_ERR(inode)) {
> err = PTR_ERR(inode);
> - /* the directory was completed, just return a error */
> + err2 = fat_remove_entries(dir, &sinfo);
> + if (err2)
> + fat_msg(sb, KERN_WARNING,
> + "failed to roll back new entry (%d)", err2);
> + drop_nlink(dir);
ditto
> + fat_free_clusters(dir, cluster);
out_free?
> goto out;
> }
> + brelse(sinfo.bh);
> inode_inc_iversion(inode);
> set_nlink(inode, 2);
Thanks.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH v2] fat: roll back the new entry when create/mkdir fails to build the inode
2026-10-12 9:24 ` OGAWA Hirofumi
@ 2026-10-12 13:20 ` zhoumin
0 siblings, 0 replies; 3+ messages in thread
From: zhoumin @ 2026-10-12 13:20 UTC (permalink / raw)
To: hirofumi; +Cc: linux-kernel, teczm
vfat_create(), vfat_mkdir(), msdos_create() and msdos_mkdir() add the
on-disk entry before calling fat_build_inode() to set up the VFS
inode. If fat_build_inode() fails, the error is returned but the
entry stays on disk and the file or directory shows up after remount.
Remove the entry in that case. For mkdir, also free the directory
cluster and decrement the parent's link count.
Signed-off-by: zhoumin <teczm@foxmail.com>
---
Changes since v1:
- Only undo the parent nlink and free the cluster when
fat_remove_entries() succeeds.
- Use a block scoped err2.
- Reuse out_free instead of an open coded fat_free_clusters().
fs/fat/namei_msdos.c | 22 ++++++++++++++++++----
fs/fat/namei_vfat.c | 22 ++++++++++++++++++----
2 files changed, 36 insertions(+), 8 deletions(-)
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index d46d1a3851f2..7f2c68149efd 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -292,11 +292,17 @@ static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
if (err)
goto out;
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
+ int err2;
+
err = PTR_ERR(inode);
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2)
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
goto out;
}
+ brelse(sinfo.bh);
fat_truncate_time(inode, &ts, FAT_UPDATE_ATIME | FAT_UPDATE_CMTIME);
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
@@ -381,12 +387,20 @@ static struct dentry *msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir,
inc_nlink(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
+ int err2;
+
err = PTR_ERR(inode);
- /* the directory was completed, just return a error */
- goto out;
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2) {
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
+ goto out;
+ }
+ drop_nlink(dir);
+ goto out_free;
}
+ brelse(sinfo.bh);
set_nlink(inode, 2);
fat_truncate_time(inode, &ts, FAT_UPDATE_ATIME | FAT_UPDATE_CMTIME);
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index da3e89c0b16a..b366e0163272 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -771,11 +771,17 @@ static int vfat_create(struct mnt_idmap *idmap, struct inode *dir,
inode_inc_iversion(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
+ int err2;
+
err = PTR_ERR(inode);
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2)
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
goto out;
}
+ brelse(sinfo.bh);
inode_inc_iversion(inode);
d_instantiate(dentry, inode);
@@ -870,12 +876,20 @@ static struct dentry *vfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
inc_nlink(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
- brelse(sinfo.bh);
if (IS_ERR(inode)) {
+ int err2;
+
err = PTR_ERR(inode);
- /* the directory was completed, just return a error */
- goto out;
+ err2 = fat_remove_entries(dir, &sinfo);
+ if (err2) {
+ fat_msg(sb, KERN_WARNING,
+ "failed to roll back new entry (%d)", err2);
+ goto out;
+ }
+ drop_nlink(dir);
+ goto out_free;
}
+ brelse(sinfo.bh);
inode_inc_iversion(inode);
set_nlink(inode, 2);
--
2.53.0
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-10-12 13:21 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2026-10-12 6:43 [PATCH] fat: roll back the new entry when create/mkdir fails to build the inode zhoumin
2026-10-12 9:24 ` OGAWA Hirofumi
2026-10-12 13:20 ` [PATCH v2] " zhoumin
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