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  1. 18 Nov, 2021 1 commit
  3. 03 Sep, 2021 1 commit
  5. 23 Aug, 2021 1 commit
    • Josef Bacik's avatar
      fs: add a filemap_fdatawrite_wbc helper · 5a798493
      Josef Bacik authored 
      
Btrfs sometimes needs to flush dirty pages on a bunch of dirty inodes in
order to reclaim metadata reservations.  Unfortunately most helpers in
this area are too smart for us:

1) The normal filemap_fdata* helpers only take range and sync modes, and
   don't give any indication of how much was written, so we can only
   flush full inodes, which isn't what we want in most cases.
2) The normal writeback path requires us to have the s_umount sem held,
   but we can't unconditionally take it in this path because we could
   deadlock.
3) The normal writeback path also skips inodes with I_SYNC set if we
   write with WB_SYNC_NONE.  This isn't the behavior we want under heavy
   ENOSPC pressure, we want to actually make sure the pages are under
   writeback before returning, and if another thread is in the middle of
   writing the file we may return before they're under writeback and
   miss our ordered extents and not properly wait for completion.
4) sync_inode() uses the normal writeback path and has the same problem
   as #3.

What we really want is to call do_writepages() with our wbc.  This way
we can make sure that writeback is actually started on the pages, and we
can control how many pages are written as a whole as we write many
inodes using the same wbc.  Accomplish this with a new helper that does
just that so we can use it for our ENOSPC flushing infrastructure.
Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      5a798493
  7. 13 Jul, 2021 2 commits
    • Jan Kara's avatar
      mm: Add functions to lock invalidate_lock for two mappings · 7506ae6a
      Jan Kara authored 
      
Some operations such as reflinking blocks among files will need to lock
invalidate_lock for two mappings. Add helper functions to do that.
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
      7506ae6a
    • Jan Kara's avatar
      mm: Protect operations adding pages to page cache with invalidate_lock · 730633f0
      Jan Kara authored 
      
Currently, serializing operations such as page fault, read, or readahead
against hole punching is rather difficult. The basic race scheme is
like:

fallocate(FALLOC_FL_PUNCH_HOLE)			read / fault / ..
  truncate_inode_pages_range()
						  <create pages in page
						   cache here>
  <update fs block mapping and free blocks>

Now the problem is in this way read / page fault / readahead can
instantiate pages in page cache with potentially stale data (if blocks
get quickly reused). Avoiding this race is not simple - page locks do
not work because we want to make sure there are *no* pages in given
range. inode->i_rwsem does not work because page fault happens under
mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes
the performance for mixed read-write workloads suffer.

So create a new rw_semaphore in the address_space - invalidate_lock -
that protects adding of pages to page cache for page faults / reads /
readahead.
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
      730633f0
  9. 12 Jul, 2021 1 commit
  11. 29 Jun, 2021 1 commit
  13. 10 Jun, 2021 1 commit
  15. 02 Jun, 2021 1 commit
  17. 07 May, 2021 1 commit
  19. 05 May, 2021 3 commits
  21. 30 Apr, 2021 5 commits
  23. 23 Apr, 2021 4 commits
  25. 26 Feb, 2021 9 commits
  27. 24 Feb, 2021 9 commits