libfs: Add simple_offset_rename() API

I'm about to fix a tmpfs rename bug that requires the use of
internal simple_offset helpers that are not available in mm/shmem.c

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-3-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Chuck Lever 2024-04-15 11:20:55 -04:00 committed by Christian Brauner
parent 23cdd0eed3
commit 5a1a25be99
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3 changed files with 24 additions and 2 deletions

View File

@ -357,6 +357,27 @@ int simple_offset_empty(struct dentry *dentry)
return ret;
}
/**
* simple_offset_rename - handle directory offsets for rename
* @old_dir: parent directory of source entry
* @old_dentry: dentry of source entry
* @new_dir: parent_directory of destination entry
* @new_dentry: dentry of destination
*
* Caller provides appropriate serialization.
*
* Returns zero on success, a negative errno value on failure.
*/
int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct offset_ctx *old_ctx = old_dir->i_op->get_offset_ctx(old_dir);
struct offset_ctx *new_ctx = new_dir->i_op->get_offset_ctx(new_dir);
simple_offset_remove(old_ctx, old_dentry);
return simple_offset_add(new_ctx, old_dentry);
}
/**
* simple_offset_rename_exchange - exchange rename with directory offsets
* @old_dir: parent of dentry being moved

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@ -3338,6 +3338,8 @@ 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_empty(struct dentry *dentry);
int 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,
struct inode *new_dir,

View File

@ -3473,8 +3473,7 @@ static int shmem_rename2(struct mnt_idmap *idmap,
return error;
}
simple_offset_remove(shmem_get_offset_ctx(old_dir), old_dentry);
error = simple_offset_add(shmem_get_offset_ctx(new_dir), old_dentry);
error = simple_offset_rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
return error;