This patch series add support to xfs for the new kernel mount API as described in the LWN article at https://lwn.net/Articles/780267/. In the article there's a lengthy description of the reasons for adopting the API and problems expected to be resolved by using it. The series has been applied to the repository located at git://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git, and built and some simple tests run on it. Other things that continue to cause me concern: - Message logging. There is error logging done in the VFS by the mount-api code, some is VFS specific while some is file system specific. This can lead to duplicated and often inconsistent logging. The mount-api feature of saving error message text to the mount context for later retrival by fsopen()/fsconfig()/fsmount() users is the reason the mount-api log macros are present. But, at the moment (last time I looked), these macros will either log the error message or save it to the mount context, there's not yet a way to modify this behaviour which can lead to messages, possibly needed for debug purposes, being lost. There's also the pr_xxx() log functions (not a problem for xfs AFAICS) that aren't aware of the mount context. Consequently I've tried to keep logging as it is in xfs and also tried to avoid duplicate log messages, deferring mount context messaging until more work has been done on mount-api convesions so that further discussions can take place. - That large comment about mount option handling. I'm not sure what to do about that large comment. On one hand I think there's useful information there and don't really want to para-phrase it (largely) out of existence, not knowing of a sensible place to put it so I can refer to it instead. Changes for v3: - fix struct xfs_fs_context initialization in xfs_parseargs(). - move call to xfs_validate_params() below label "done". - if allocation of xfs_mount fails return ENOMEM immediately. - remove erroneous kfree(mp) in xfs_fill_super(). - move the removal of xfs_fs_remount() and xfs_test_remount_options() to the switch to mount api patch. - retain original usage of distinct <option>, no<option> usage. - fix line length and a white space problem in xfs_parseargs(). - defer introduction of struct fs_context_operations until mount api implementation. - don't use a new line for the void parameter of xfs_mount_alloc(). - check for -ENOPARAM in xfs_parse_param() to report invalid options using the options switch (to avoid double entry log messages). - remove obolete mount option biosize. - try and make comment in xfs_fc_free() more understandable. Changes for v2: - changed .name to uppercase in fs_parameter_description to ensure consistent error log messages between the vfs parser and the xfs parameter parser. - clearify comment above xfs_parse_param() about when possibly allocated mp->m_logname or mp->m_rtname are freed. - factor out xfs_remount_rw() and xfs_remount_ro() from xfs_remount(). - changed xfs_mount_alloc() to not set super block in xfs_mount so it can be re-used when switching to the mount-api. - fixed don't check for NULL when calling kfree() in xfs_fc_free(). - refactored xfs_parseargs() in an attempt to highlight the code that actually changes in converting to use the new mount api. - dropped xfs-mount-api-rename-xfs_fill_super.patch, it didn't seem necessary. - move comment about remount difficulties above xfs_reconfigure() and increase line length to try and make the comment managable. Al Viro has sent a pull request to Linus for the patch containing the vfs_get_block_super() just recently so there will be conflicts if this series is merged without dropping that patch. --- David Howells (1): vfs: Create fs_context-aware mount_bdev() replacement Ian Kent (15): xfs: remove very old mount option xfs: mount-api - add fs parameter description xfs: mount-api - refactor suffix_kstrtoint() xfs: mount-api - refactor xfs_parseags() xfs: mount-api - make xfs_parse_param() take context .parse_param() args xfs: mount-api - move xfs_parseargs() validation to a helper xfs: mount-api - refactor xfs_fs_fill_super() xfs: mount-api - add xfs_get_tree() xfs: mount-api - add xfs_remount_rw() helper xfs: mount-api - add xfs_remount_ro() helper xfs: mount api - add xfs_reconfigure() xfs: mount-api - add xfs_fc_free() xfs: mount-api - dont set sb in xfs_mount_alloc() xfs: mount-api - switch to new mount-api xfs: mount-api - remove legacy mount functions fs/fs_context.c | 2 fs/super.c | 111 +++++ fs/xfs/xfs_super.c | 960 ++++++++++++++++++++++++-------------------- include/linux/fs_context.h | 9 4 files changed, 642 insertions(+), 440 deletions(-) -- Ian
