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| author | Al Viro <viro@zeniv.linux.org.uk> | 2025-12-14 01:50:23 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-01-08 12:13:54 +0300 |
| commit | 4b0fe71fb3965d0db83cdfc2f4fe0b3227d70113 (patch) | |
| tree | 0b194af031a9349b378f04652cdc55709281c1d8 /include | |
| parent | e065fc63ecc1612cc6229d4fb21044a66d5670d5 (diff) | |
| download | linux-4b0fe71fb3965d0db83cdfc2f4fe0b3227d70113.tar.xz | |
shmem: fix recovery on rename failures
[ Upstream commit e1b4c6a58304fd490124cc2b454d80edc786665c ]
maple_tree insertions can fail if we are seriously short on memory;
simple_offset_rename() does not recover well if it runs into that.
The same goes for simple_offset_rename_exchange().
Moreover, shmem_whiteout() expects that if it succeeds, the caller will
progress to d_move(), i.e. that shmem_rename2() won't fail past the
successful call of shmem_whiteout().
Not hard to fix, fortunately - mtree_store() can't fail if the index we
are trying to store into is already present in the tree as a singleton.
For simple_offset_rename_exchange() that's enough - we just need to be
careful about the order of operations.
For simple_offset_rename() solution is to preinsert the target into the
tree for new_dir; the rest can be done without any potentially failing
operations.
That preinsertion has to be done in shmem_rename2() rather than in
simple_offset_rename() itself - otherwise we'd need to deal with the
possibility of failure after successful shmem_whiteout().
Fixes: a2e459555c5f ("shmem: stable directory offsets")
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fs.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 37a01c9d9658..87720e1b5419 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3446,7 +3446,7 @@ struct offset_ctx { void simple_offset_init(struct offset_ctx *octx); int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry); void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry); -int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, +void simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry); int simple_offset_rename_exchange(struct inode *old_dir, struct dentry *old_dentry, |