linux.git/fs/fuse/file.c, branch v4.20

fuse: continue to send FUSE_RELEASEDIR when FUSE_OPEN returns ENOSYS

2018-12-11T20:47:28+00:00

When FUSE_OPEN returns ENOSYS, the no_open bit is set on the connection.

Because the FUSE_RELEASE and FUSE_RELEASEDIR paths share code, this
incorrectly caused the FUSE_RELEASEDIR request to be dropped and never sent
to userspace.

Pass an isdir bool to distinguish between FUSE_RELEASE and FUSE_RELEASEDIR
inside of fuse_file_put.

Fixes: 7678ac50615d ("fuse: support clients that don't implement 'open'")
Cc:  # v3.14
Signed-off-by: Chad Austin 
Signed-off-by: Miklos Szeredi

fuse: fix fsync on directory

2018-12-03T09:14:43+00:00

Commit ab2257e9941b ("fuse: reduce size of struct fuse_inode") moved parts
of fields related to writeback on regular file and to directory caching
into a union.  However fuse_fsync_common() called from fuse_dir_fsync()
touches some writeback related fields, resulting in a crash.

Move writeback related parts from fuse_fsync_common() to fuse_fysnc().

Reported-by: Brett Girton 
Tested-by: Brett Girton 
Fixes: ab2257e9941b ("fuse: reduce size of struct fuse_inode")
Signed-off-by: Miklos Szeredi

fuse: fix use-after-free in fuse_direct_IO()

2018-11-09T14:52:17+00:00

In async IO blocking case the additional reference to the io is taken for
it to survive fuse_aio_complete(). In non blocking case this additional
reference is not needed, however we still reference io to figure out
whether to wait for completion or not. This is wrong and will lead to
use-after-free. Fix it by storing blocking information in separate
variable.

This was spotted by KASAN when running generic/208 fstest.

Signed-off-by: Lukas Czerner 
Reported-by: Zorro Lang 
Signed-off-by: Miklos Szeredi 
Fixes: 744742d692e3 ("fuse: Add reference counting for fuse_io_priv")
Cc:  # v4.6

Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-11-02T02:58:52+00:00

Pull AFS updates from Al Viro:
 "AFS series, with some iov_iter bits included"

* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  missing bits of "iov_iter: Separate type from direction and use accessor functions"
  afs: Probe multiple fileservers simultaneously
  afs: Fix callback handling
  afs: Eliminate the address pointer from the address list cursor
  afs: Allow dumping of server cursor on operation failure
  afs: Implement YFS support in the fs client
  afs: Expand data structure fields to support YFS
  afs: Get the target vnode in afs_rmdir() and get a callback on it
  afs: Calc callback expiry in op reply delivery
  afs: Fix FS.FetchStatus delivery from updating wrong vnode
  afs: Implement the YFS cache manager service
  afs: Remove callback details from afs_callback_break struct
  afs: Commit the status on a new file/dir/symlink
  afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
  afs: Don't invoke the server to read data beyond EOF
  afs: Add a couple of tracepoints to log I/O errors
  afs: Handle EIO from delivery function
  afs: Fix TTL on VL server and address lists
  afs: Implement VL server rotation
  afs: Improve FS server rotation error handling
  ...

iov_iter: Use accessor function

2018-10-23T23:40:44+00:00

Use accessor functions to access an iterator's type and direction.  This
allows for the possibility of using some other method of determining the
type of iterator than if-chains with bitwise-AND conditions.

Signed-off-by: David Howells

fuse: only invalidate atime in direct read

2018-10-15T13:43:06+00:00

After sending a synchronous READ request from __fuse_direct_read() we only
need to invalidate atime; none of the other attributes should be changed by
a read().

Signed-off-by: Miklos Szeredi

fuse: realloc page array

2018-10-01T08:07:06+00:00

Writeback caching currently allocates requests with the maximum number of
possible pages, while the actual number of pages per request depends on a
couple of factors that cannot be determined when the request is allocated
(whether page is already under writeback, whether page is contiguous with
previous pages already added to a request).

This patch allows such requests to start with no page allocation (all pages
inline) and grow the page array on demand.

If the max_pages tunable remains the default value, then this will mean
just one allocation that is the same size as before.  If the tunable is
larger, then this adds at most 3 additional memory allocations (which is
generously compensated by the improved performance from the larger
request).

Signed-off-by: Miklos Szeredi

fuse: add max_pages to init_out

2018-10-01T08:07:06+00:00

Replace FUSE_MAX_PAGES_PER_REQ with the configurable parameter max_pages to
improve performance.

Old RFC with detailed description of the problem and many fixes by Mitsuo
Hayasaka (mitsuo.hayasaka.hu@hitachi.com):
 - https://lkml.org/lkml/2012/7/5/136

We've encountered performance degradation and fixed it on a big and complex
virtual environment.

Environment to reproduce degradation and improvement:

1. Add lag to user mode FUSE
Add nanosleep(&(struct timespec){ 0, 1000 }, NULL); to xmp_write_buf in
passthrough_fh.c

2. patch UM fuse with configurable max_pages parameter. The patch will be
provided latter.

3. run test script and perform test on tmpfs
fuse_test()
{

       cd /tmp
       mkdir -p fusemnt
       passthrough_fh -o max_pages=$1 /tmp/fusemnt
       grep fuse /proc/self/mounts
       dd conv=fdatasync oflag=dsync if=/dev/zero of=fusemnt/tmp/tmp \
		count=1K bs=1M 2>&1 | grep -v records
       rm fusemnt/tmp/tmp
       killall passthrough_fh
}

Test results:

passthrough_fh /tmp/fusemnt fuse.passthrough_fh \
	rw,nosuid,nodev,relatime,user_id=0,group_id=0 0 0
1073741824 bytes (1.1 GB) copied, 1.73867 s, 618 MB/s

passthrough_fh /tmp/fusemnt fuse.passthrough_fh \
	rw,nosuid,nodev,relatime,user_id=0,group_id=0,max_pages=256 0 0
1073741824 bytes (1.1 GB) copied, 1.15643 s, 928 MB/s

Obviously with bigger lag the difference between 'before' and 'after'
will be more significant.

Mitsuo Hayasaka, in 2012 (https://lkml.org/lkml/2012/7/5/136),
observed improvement from 400-550 to 520-740.

Signed-off-by: Constantine Shulyupin 
Signed-off-by: Miklos Szeredi

fuse: reduce size of struct fuse_inode

2018-10-01T08:07:05+00:00

Do this by grouping fields used for cached writes and putting them into a
union with fileds used for cached readdir (with obviously no overlap, since
we don't have hybrid objects).

Signed-off-by: Miklos Szeredi

fuse: allow using readdir cache

2018-10-01T08:07:04+00:00

The cache is only used if it's completed, not while it's still being
filled; this constraint could be lifted later, if it turns out to be
useful.

Introduce state in struct fuse_file that indicates the position within the
cache.  After a seek, reset the position to the beginning of the cache and
search the cache for the current position.  If the current position is not
found in the cache, then fall back to uncached readdir.

It can also happen that page(s) disappear from the cache, in which case we
must also fall back to uncached readdir.

Signed-off-by: Miklos Szeredi