* [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
end of thread, other threads:[~2024-02-11 7:49 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 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
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