diff options
Diffstat (limited to 'Documentation/filesystems/porting')
| -rw-r--r-- | Documentation/filesystems/porting | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 17bb4dc28fae..cf43bc4dbf31 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -602,3 +602,39 @@ in your dentry operations instead. dentry separately, and it now has request_mask and query_flags arguments to specify the fields and sync type requested by statx. Filesystems not supporting any statx-specific features may ignore the new arguments. +-- +[mandatory] + ->atomic_open() calling conventions have changed. Gone is int *opened, + along with FILE_OPENED/FILE_CREATED. In place of those we have + FMODE_OPENED/FMODE_CREATED, set in file->f_mode. Additionally, return + value for 'called finish_no_open(), open it yourself' case has become + 0, not 1. Since finish_no_open() itself is returning 0 now, that part + does not need any changes in ->atomic_open() instances. +-- +[mandatory] + alloc_file() has become static now; two wrappers are to be used instead. + alloc_file_pseudo(inode, vfsmount, name, flags, ops) is for the cases + when dentry needs to be created; that's the majority of old alloc_file() + users. Calling conventions: on success a reference to new struct file + is returned and callers reference to inode is subsumed by that. On + failure, ERR_PTR() is returned and no caller's references are affected, + so the caller needs to drop the inode reference it held. + alloc_file_clone(file, flags, ops) does not affect any caller's references. + On success you get a new struct file sharing the mount/dentry with the + original, on failure - ERR_PTR(). +-- +[mandatory] + ->clone_file_range() and ->dedupe_file_range have been replaced with + ->remap_file_range(). See Documentation/filesystems/vfs.txt for more + information. +-- +[recommended] + ->lookup() instances doing an equivalent of + if (IS_ERR(inode)) + return ERR_CAST(inode); + return d_splice_alias(inode, dentry); + don't need to bother with the check - d_splice_alias() will do the + right thing when given ERR_PTR(...) as inode. Moreover, passing NULL + inode to d_splice_alias() will also do the right thing (equivalent of + d_add(dentry, NULL); return NULL;), so that kind of special cases + also doesn't need a separate treatment. |