fs/9p: mitigate inode collisions
Detect and mitigate inode collsions that now occur since we
fixed 9p generating duplicate inode structures. Underlying
cause of these appears to be a race condition between reuse
of inode numbers in underlying file system and cleanup of
inode numbers in the client. Enabling caching
makes this much more likely to happen as it increases cleanup
latency due to writebacks.
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 9defa12..1775fcc 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -179,13 +179,14 @@ extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags);
-extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid);
+extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid,
+ bool new);
extern const struct inode_operations v9fs_dir_inode_operations_dotl;
extern const struct inode_operations v9fs_file_inode_operations_dotl;
extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
extern const struct netfs_request_ops v9fs_req_ops;
extern struct inode *v9fs_fid_iget_dotl(struct super_block *sb,
- struct p9_fid *fid);
+ struct p9_fid *fid, bool new);
/* other default globals */
#define V9FS_PORT 564
@@ -224,12 +225,12 @@ static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
*/
static inline struct inode *
v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
- struct super_block *sb)
+ struct super_block *sb, bool new)
{
if (v9fs_proto_dotl(v9ses))
- return v9fs_fid_iget_dotl(sb, fid);
+ return v9fs_fid_iget_dotl(sb, fid, new);
else
- return v9fs_fid_iget(sb, fid);
+ return v9fs_fid_iget(sb, fid, new);
}
#endif
