kernel/linux.git/fs/fuse/dax.c, branch linux-6.0.y

fuse: avoid unnecessary spinlock bump

2022-07-21T14:02:45+00:00

Move dmap free worker kicker inside the critical region, so that extra spinlock lock/unlock could be avoided. Suggested-by: Liu Jiang Signed-off-by: Jeffle Xu Reviewed-by: Stefan Hajnoczi Reviewed-by: Vivek Goyal Signed-off-by: Miklos Szeredi

dax: introduce DAX_RECOVERY_WRITE dax access mode

2022-05-16T20:35:56+00:00

Up till now, dax_direct_access() is used implicitly for normal access, but for the purpose of recovery write, dax range with poison is requested. To make the interface clear, introduce enum dax_access_mode { DAX_ACCESS, DAX_RECOVERY_WRITE, } where DAX_ACCESS is used for normal dax access, and DAX_RECOVERY_WRITE is used for dax recovery write. Suggested-by: Dan Williams Signed-off-by: Jane Chu Reviewed-by: Christoph Hellwig Cc: Mike Snitzer Reviewed-by: Vivek Goyal Link: https://lore.kernel.org/r/165247982851.52965.11024212198889762949.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams

fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio

2022-03-16T17:37:05+00:00

This is a mechanical change. Signed-off-by: Matthew Wilcox (Oracle) Tested-by: Damien Le Moal Acked-by: Damien Le Moal Tested-by: Mike Marshall # orangefs Tested-by: David Howells # afs

fs: Remove noop_invalidatepage()

2022-03-15T12:23:29+00:00

We used to have to use noop_invalidatepage() to prevent block_invalidatepage() from being called, but that behaviour is now gone. Signed-off-by: Matthew Wilcox (Oracle) Tested-by: Damien Le Moal Acked-by: Damien Le Moal Tested-by: Mike Marshall # orangefs Tested-by: David Howells # afs

fuse: mark inode DONT_CACHE when per inode DAX hint changes

2021-12-14T10:09:37+00:00

When the per inode DAX hint changes while the file is still *opened*, it is quite complicated and maybe fragile to dynamically change the DAX state. Hence mark the inode and corresponding dentries as DONE_CACHE once the per inode DAX hint changes, so that the inode instance will be evicted and freed as soon as possible once the file is closed and the last reference to the inode is put. And then when the file gets reopened next time, the new instantiated inode will reflect the new DAX state. In summary, when the per inode DAX hint changes for an *opened* file, the DAX state of the file won't be updated until this file is closed and reopened later. Signed-off-by: Jeffle Xu Reviewed-by: Vivek Goyal Signed-off-by: Miklos Szeredi

fuse: negotiate per inode DAX in FUSE_INIT

2021-12-14T10:09:37+00:00

Among the FUSE_INIT phase, client shall advertise per inode DAX if it's mounted with "dax=inode". Then server is aware that client is in per inode DAX mode, and will construct per-inode DAX attribute accordingly. Server shall also advertise support for per inode DAX. If server doesn't support it while client is mounted with "dax=inode", client will silently fallback to "dax=never" since "dax=inode" is advisory only. Signed-off-by: Jeffle Xu Reviewed-by: Vivek Goyal Signed-off-by: Miklos Szeredi

fuse: enable per inode DAX

2021-12-14T10:09:37+00:00

DAX may be limited in some specific situation. When the number of usable DAX windows is under watermark, the recalim routine will be triggered to reclaim some DAX windows. It may have a negative impact on the performance, since some processes may need to wait for DAX windows to be recalimed and reused then. To mitigate the performance degradation, the overall DAX window need to be expanded larger. However, simply expanding the DAX window may not be a good deal in some scenario. To maintain one DAX window chunk (i.e., 2MB in size), 32KB (512 * 64 bytes) memory footprint will be consumed for page descriptors inside guest, which is greater than the memory footprint if it uses guest page cache when DAX disabled. Thus it'd better disable DAX for those files smaller than 32KB, to reduce the demand for DAX window and thus avoid the unworthy memory overhead. Per inode DAX feature is introduced to address this issue, by offering a finer grained control for dax to users, trying to achieve a balance between performance and memory overhead. The FUSE_ATTR_DAX flag in FUSE_LOOKUP reply is used to indicate whether DAX should be enabled or not for corresponding file. Currently the state whether DAX is enabled or not for the file is initialized only when inode is instantiated. Signed-off-by: Jeffle Xu Reviewed-by: Vivek Goyal Signed-off-by: Miklos Szeredi

fuse: make DAX mount option a tri-state

2021-12-14T10:09:36+00:00

We add 'always', 'never', and 'inode' (default). '-o dax' continues to operate the same which is equivalent to 'always'. The following behavior is consistent with that on ext4/xfs: - The default behavior (when neither '-o dax' nor '-o dax=always|never|inode' option is specified) is equal to 'inode' mode, while 'dax=inode' won't be printed among the mount option list. - The 'inode' mode is only advisory. It will silently fallback to 'never' mode if fuse server doesn't support that. Also noted that by the time of this commit, 'inode' mode is actually equal to 'always' mode, before the per inode DAX flag is introduced in the following patch. Signed-off-by: Jeffle Xu Reviewed-by: Vivek Goyal Signed-off-by: Miklos Szeredi

fuse: add fuse_should_enable_dax() helper

2021-12-14T10:09:36+00:00

This is in prep for following per inode DAX checking. Signed-off-by: Jeffle Xu Reviewed-by: Vivek Goyal Signed-off-by: Miklos Szeredi

fuse: always invalidate attributes after writes

2021-10-28T07:45:32+00:00

Extend the fuse_write_update_attr() helper to invalidate cached attributes after a write. This has already been done in all cases except in fuse_notify_store(), so this is mostly a cleanup. fuse_direct_write_iter() calls fuse_direct_IO() which already calls fuse_write_update_attr(), so don't repeat that again in the former. Signed-off-by: Miklos Szeredi