linux.git/fs/fuse/dax.c, branch for-next

virtiofs: dax: remove ->writepages() callback

2024-11-18T11:24:38+00:00

When using FUSE DAX with virtiofs, cache coherency is managed by the
host. Disk persistence is handled via fsync() and friends, which are
passed directly via the FUSE layer to the host. Therefore, there's no
need to do dax_writeback_mapping_range(). All that ends up doing is a
cache flush operation, which is not caught by KVM and doesn't do much,
since the host and guest are already cache-coherent.

Since dax_writeback_mapping_range() checks that the inode block size is
equal to PAGE_SIZE, this fixes a spurious WARN when virtiofs is used
with a mismatched guest PAGE_SIZE and virtiofs backing FS block size
(this happens, for example, when it's a tmpfs and the host and guest
have a different PAGE_SIZE). FUSE DAX does not require any particular FS
block size, since it always performs DAX mappings in aligned 2MiB
blocks.

See discussion in [1].

[1] https://lore.kernel.org/lkml/20241101-dax-page-size-v1-1-eedbd0c6b08f@asahilina.net/T/#u

[SzM: remove the empty callback]

Suggested-by: Dan Williams 
Signed-off-by: Asahi Lina 
Acked-by: Dan Williams 
Signed-off-by: Miklos Szeredi

fuse: dax: set fc->dax to NULL in fuse_dax_conn_free()

2023-12-04T09:16:53+00:00

fuse_dax_conn_free() will be called when fuse_fill_super_common() fails
after fuse_dax_conn_alloc(). Then deactivate_locked_super() in
virtio_fs_get_tree() will call virtio_kill_sb() to release the discarded
superblock. This will call fuse_dax_conn_free() again in fuse_conn_put(),
resulting in a possible double free.

Fixes: 1dd539577c42 ("virtiofs: add a mount option to enable dax")
Signed-off-by: Hangyu Hua 
Acked-by: Vivek Goyal 
Reviewed-by: Jingbo Xu 
Cc:  # v5.10
Signed-off-by: Miklos Szeredi

mm: remove enum page_entry_size

2023-08-24T23:20:30+00:00

Remove the unnecessary encoding of page order into an enum and pass the
page order directly.  That lets us get rid of pe_order().

The switch constructs have to be changed to if/else constructs to prevent
GCC from warning on builds with 3-level page tables where PMD_ORDER and
PUD_ORDER have the same value.

If you are looking at this commit because your driver stopped compiling,
look at the previous commit as well and audit your driver to be sure it
doesn't depend on mmap_lock being held in its ->huge_fault method.

[willy@infradead.org: use "order %u" to match the (non dev_t) style]
  Link: https://lkml.kernel.org/r/ZOUYekbtTv+n8hYf@casper.infradead.org
Link: https://lkml.kernel.org/r/20230818202335.2739663-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton

mm: replace vma->vm_flags direct modifications with modifier calls

2023-02-10T00:51:39+00:00

Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.

[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan 
Acked-by: Michal Hocko 
Acked-by: Mel Gorman 
Acked-by: Mike Rapoport (IBM) 
Acked-by: Sebastian Reichel 
Reviewed-by: Liam R. Howlett 
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski 
Cc: Arjun Roy 
Cc: Axel Rasmussen 
Cc: David Hildenbrand 
Cc: David Howells 
Cc: Davidlohr Bueso 
Cc: David Rientjes 
Cc: Eric Dumazet 
Cc: Greg Thelen 
Cc: Hugh Dickins 
Cc: Ingo Molnar 
Cc: Jann Horn 
Cc: Joel Fernandes 
Cc: Johannes Weiner 
Cc: Kent Overstreet 
Cc: Laurent Dufour 
Cc: Lorenzo Stoakes 
Cc: Matthew Wilcox 
Cc: Minchan Kim 
Cc: Paul E. McKenney 
Cc: Peter Oskolkov 
Cc: Peter Xu 
Cc: Peter Zijlstra 
Cc: Punit Agrawal 
Cc: Sebastian Andrzej Siewior 
Cc: Shakeel Butt 
Cc: Soheil Hassas Yeganeh 
Cc: Song Liu 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

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