* [PATCH] bcachefs: skip invisible entries in empty subvolume checking
@ 2024-02-10 14:06 Guoyu Ou
2024-02-10 22:56 ` Kent Overstreet
0 siblings, 1 reply; 3+ messages in thread
From: Guoyu Ou @ 2024-02-10 14:06 UTC (permalink / raw)
To: kent.overstreet; +Cc: linux-bcachefs, Guoyu Ou
When we are checking whether a subvolume is empty in the specified snapshot,
entries that do not belong to this subvolume should be skipped.
This fixes the following case:
$ bcachefs subvolume create ./sub
$ cd sub
$ bcachefs subvolume create ./sub2
$ bcachefs subvolume snapshot . ./snap
$ ls -a snap
. ..
$ rmdir snap
rmdir: failed to remove 'snap': Directory not empty
Signed-off-by: Guoyu Ou <benogy@gmail.com>
---
fs/bcachefs/dirent.c | 7 +++++--
fs/bcachefs/dirent.h | 2 +-
fs/bcachefs/inode.c | 2 +-
3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
index 4ae1e9f002a0..82c5bff01411 100644
--- a/fs/bcachefs/dirent.c
+++ b/fs/bcachefs/dirent.c
@@ -508,7 +508,7 @@ u64 bch2_dirent_lookup(struct bch_fs *c, subvol_inum dir,
return ret;
}
-int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
+int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 subvol, u32 snapshot)
{
struct btree_iter iter;
struct bkey_s_c k;
@@ -518,6 +518,9 @@ int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
SPOS(dir, 0, snapshot),
POS(dir, U64_MAX), 0, k, ret)
if (k.k->type == KEY_TYPE_dirent) {
+ struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
+ if (d.v->d_type == DT_SUBVOL && le32_to_cpu(d.v->d_parent_subvol) != subvol)
+ continue;
ret = -ENOTEMPTY;
break;
}
@@ -531,7 +534,7 @@ int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
u32 snapshot;
return bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot) ?:
- bch2_empty_dir_snapshot(trans, dir.inum, snapshot);
+ bch2_empty_dir_snapshot(trans, dir.inum, dir.subvol, snapshot);
}
int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
index 21ffeb78f02e..aeb8207ca9f2 100644
--- a/fs/bcachefs/dirent.h
+++ b/fs/bcachefs/dirent.h
@@ -69,7 +69,7 @@ u64 bch2_dirent_lookup(struct bch_fs *, subvol_inum,
const struct bch_hash_info *,
const struct qstr *, subvol_inum *);
-int bch2_empty_dir_snapshot(struct btree_trans *, u64, u32);
+int bch2_empty_dir_snapshot(struct btree_trans *, u64, u32, u32);
int bch2_empty_dir_trans(struct btree_trans *, subvol_inum);
int bch2_readdir(struct bch_fs *, subvol_inum, struct dir_context *);
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 086f0090b03a..8f85d0132cc2 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -1088,7 +1088,7 @@ static int may_delete_deleted_inode(struct btree_trans *trans,
goto out;
if (S_ISDIR(inode.bi_mode)) {
- ret = bch2_empty_dir_snapshot(trans, pos.offset, pos.snapshot);
+ ret = bch2_empty_dir_snapshot(trans, pos.offset, inode.bi_subvol, pos.snapshot);
if (fsck_err_on(ret == -ENOTEMPTY, c, deleted_inode_is_dir,
"non empty directory %llu:%u in deleted_inodes btree",
pos.offset, pos.snapshot))
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] bcachefs: skip invisible entries in empty subvolume checking
2024-02-10 14:06 [PATCH] bcachefs: skip invisible entries in empty subvolume checking Guoyu Ou
@ 2024-02-10 22:56 ` Kent Overstreet
2024-02-11 7:49 ` Guoyu Ou
0 siblings, 1 reply; 3+ messages in thread
From: Kent Overstreet @ 2024-02-10 22:56 UTC (permalink / raw)
To: Guoyu Ou; +Cc: linux-bcachefs
On Sat, Feb 10, 2024 at 10:06:37PM +0800, Guoyu Ou wrote:
> When we are checking whether a subvolume is empty in the specified snapshot,
> entries that do not belong to this subvolume should be skipped.
>
> This fixes the following case:
>
> $ bcachefs subvolume create ./sub
> $ cd sub
> $ bcachefs subvolume create ./sub2
> $ bcachefs subvolume snapshot . ./snap
> $ ls -a snap
> . ..
> $ rmdir snap
> rmdir: failed to remove 'snap': Directory not empty
>
> Signed-off-by: Guoyu Ou <benogy@gmail.com>
So that's an interesting corner case - can you add a ktest test for it?
https://evilpiepirate.org/git/ktest.git/
If you're not using it yet, please jump on IRC and ask if you run into
any issues getting it going;
There's an issue with your fix: in may_delete_deleted_inode(), you're
getting the subvol from inode.bi_subvol.
That's incorrect, because bi_subvol is only set on subvolume roots,
because we can't go through every inode in the subvolume and change
bi_subvol when taking a snapshot.
You're doing it right in bch2_empty_dir_trans(), which is the path that
matters more; may_delete_deleted_inode() is only checking "did this
filesystem get borked".
I would just pass in 0 from may_delete_deleted_inode(), and then have
empty_dir_snapshot() ignore DT_SUBVOL dirents when subvol == 0. It makes
the check less strict, but that's ok, the rest of fsck will still catch
it.
> ---
> fs/bcachefs/dirent.c | 7 +++++--
> fs/bcachefs/dirent.h | 2 +-
> fs/bcachefs/inode.c | 2 +-
> 3 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
> index 4ae1e9f002a0..82c5bff01411 100644
> --- a/fs/bcachefs/dirent.c
> +++ b/fs/bcachefs/dirent.c
> @@ -508,7 +508,7 @@ u64 bch2_dirent_lookup(struct bch_fs *c, subvol_inum dir,
> return ret;
> }
>
> -int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
> +int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 subvol, u32 snapshot)
> {
> struct btree_iter iter;
> struct bkey_s_c k;
> @@ -518,6 +518,9 @@ int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
> SPOS(dir, 0, snapshot),
> POS(dir, U64_MAX), 0, k, ret)
> if (k.k->type == KEY_TYPE_dirent) {
> + struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
> + if (d.v->d_type == DT_SUBVOL && le32_to_cpu(d.v->d_parent_subvol) != subvol)
> + continue;
> ret = -ENOTEMPTY;
> break;
> }
> @@ -531,7 +534,7 @@ int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
> u32 snapshot;
>
> return bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot) ?:
> - bch2_empty_dir_snapshot(trans, dir.inum, snapshot);
> + bch2_empty_dir_snapshot(trans, dir.inum, dir.subvol, snapshot);
> }
>
> int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
> diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
> index 21ffeb78f02e..aeb8207ca9f2 100644
> --- a/fs/bcachefs/dirent.h
> +++ b/fs/bcachefs/dirent.h
> @@ -69,7 +69,7 @@ u64 bch2_dirent_lookup(struct bch_fs *, subvol_inum,
> const struct bch_hash_info *,
> const struct qstr *, subvol_inum *);
>
> -int bch2_empty_dir_snapshot(struct btree_trans *, u64, u32);
> +int bch2_empty_dir_snapshot(struct btree_trans *, u64, u32, u32);
> int bch2_empty_dir_trans(struct btree_trans *, subvol_inum);
> int bch2_readdir(struct bch_fs *, subvol_inum, struct dir_context *);
>
> diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
> index 086f0090b03a..8f85d0132cc2 100644
> --- a/fs/bcachefs/inode.c
> +++ b/fs/bcachefs/inode.c
> @@ -1088,7 +1088,7 @@ static int may_delete_deleted_inode(struct btree_trans *trans,
> goto out;
>
> if (S_ISDIR(inode.bi_mode)) {
> - ret = bch2_empty_dir_snapshot(trans, pos.offset, pos.snapshot);
> + ret = bch2_empty_dir_snapshot(trans, pos.offset, inode.bi_subvol, pos.snapshot);
> if (fsck_err_on(ret == -ENOTEMPTY, c, deleted_inode_is_dir,
> "non empty directory %llu:%u in deleted_inodes btree",
> pos.offset, pos.snapshot))
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] bcachefs: skip invisible entries in empty subvolume checking
2024-02-10 22:56 ` Kent Overstreet
@ 2024-02-11 7:49 ` Guoyu Ou
0 siblings, 0 replies; 3+ messages in thread
From: Guoyu Ou @ 2024-02-11 7:49 UTC (permalink / raw)
To: Kent Overstreet; +Cc: linux-bcachefs, benogy
On Sat, Feb 10, 2024 at 05:56:15PM -0500, Kent Overstreet wrote:
> On Sat, Feb 10, 2024 at 10:06:37PM +0800, Guoyu Ou wrote:
> > When we are checking whether a subvolume is empty in the specified snapshot,
> > entries that do not belong to this subvolume should be skipped.
> >
> > This fixes the following case:
> >
> > $ bcachefs subvolume create ./sub
> > $ cd sub
> > $ bcachefs subvolume create ./sub2
> > $ bcachefs subvolume snapshot . ./snap
> > $ ls -a snap
> > . ..
> > $ rmdir snap
> > rmdir: failed to remove 'snap': Directory not empty
> >
> > Signed-off-by: Guoyu Ou <benogy@gmail.com>
>
> So that's an interesting corner case - can you add a ktest test for it?
> https://evilpiepirate.org/git/ktest.git/
>
> If you're not using it yet, please jump on IRC and ask if you run into
> any issues getting it going;
>
> There's an issue with your fix: in may_delete_deleted_inode(), you're
> getting the subvol from inode.bi_subvol.
>
> That's incorrect, because bi_subvol is only set on subvolume roots,
> because we can't go through every inode in the subvolume and change
> bi_subvol when taking a snapshot.
>
> You're doing it right in bch2_empty_dir_trans(), which is the path that
> matters more; may_delete_deleted_inode() is only checking "did this
> filesystem get borked".
>
> I would just pass in 0 from may_delete_deleted_inode(), and then have
> empty_dir_snapshot() ignore DT_SUBVOL dirents when subvol == 0. It makes
> the check less strict, but that's ok, the rest of fsck will still catch
> it.
Got it. I will add a new test case and update this patch later.
>
> > ---
> > fs/bcachefs/dirent.c | 7 +++++--
> > fs/bcachefs/dirent.h | 2 +-
> > fs/bcachefs/inode.c | 2 +-
> > 3 files changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
> > index 4ae1e9f002a0..82c5bff01411 100644
> > --- a/fs/bcachefs/dirent.c
> > +++ b/fs/bcachefs/dirent.c
> > @@ -508,7 +508,7 @@ u64 bch2_dirent_lookup(struct bch_fs *c, subvol_inum dir,
> > return ret;
> > }
> >
> > -int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
> > +int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 subvol, u32 snapshot)
> > {
> > struct btree_iter iter;
> > struct bkey_s_c k;
> > @@ -518,6 +518,9 @@ int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 snapshot)
> > SPOS(dir, 0, snapshot),
> > POS(dir, U64_MAX), 0, k, ret)
> > if (k.k->type == KEY_TYPE_dirent) {
> > + struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
> > + if (d.v->d_type == DT_SUBVOL && le32_to_cpu(d.v->d_parent_subvol) != subvol)
> > + continue;
> > ret = -ENOTEMPTY;
> > break;
> > }
> > @@ -531,7 +534,7 @@ int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
> > u32 snapshot;
> >
> > return bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot) ?:
> > - bch2_empty_dir_snapshot(trans, dir.inum, snapshot);
> > + bch2_empty_dir_snapshot(trans, dir.inum, dir.subvol, snapshot);
> > }
> >
> > int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
> > diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
> > index 21ffeb78f02e..aeb8207ca9f2 100644
> > --- a/fs/bcachefs/dirent.h
> > +++ b/fs/bcachefs/dirent.h
> > @@ -69,7 +69,7 @@ u64 bch2_dirent_lookup(struct bch_fs *, subvol_inum,
> > const struct bch_hash_info *,
> > const struct qstr *, subvol_inum *);
> >
> > -int bch2_empty_dir_snapshot(struct btree_trans *, u64, u32);
> > +int bch2_empty_dir_snapshot(struct btree_trans *, u64, u32, u32);
> > int bch2_empty_dir_trans(struct btree_trans *, subvol_inum);
> > int bch2_readdir(struct bch_fs *, subvol_inum, struct dir_context *);
> >
> > diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
> > index 086f0090b03a..8f85d0132cc2 100644
> > --- a/fs/bcachefs/inode.c
> > +++ b/fs/bcachefs/inode.c
> > @@ -1088,7 +1088,7 @@ static int may_delete_deleted_inode(struct btree_trans *trans,
> > goto out;
> >
> > if (S_ISDIR(inode.bi_mode)) {
> > - ret = bch2_empty_dir_snapshot(trans, pos.offset, pos.snapshot);
> > + ret = bch2_empty_dir_snapshot(trans, pos.offset, inode.bi_subvol, pos.snapshot);
> > if (fsck_err_on(ret == -ENOTEMPTY, c, deleted_inode_is_dir,
> > "non empty directory %llu:%u in deleted_inodes btree",
> > pos.offset, pos.snapshot))
> > --
> > 2.43.0
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
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