Commit Graph

912 Commits

Author SHA1 Message Date
Miklos Szeredi a2ebba8241 fuse: decrement NR_WRITEBACK_TEMP on the right page
NR_WRITEBACK_TEMP is accounted on the temporary page in the request, not
the page cache page.

Fixes: 8b284dc472 ("fuse: writepages: handle same page rewrites")
Cc: <stable@vger.kernel.org> # v3.13
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-01-16 10:27:59 +01:00
Jann Horn 9509941e9c fuse: call pipe_buf_release() under pipe lock
Some of the pipe_buf_release() handlers seem to assume that the pipe is
locked - in particular, anon_pipe_buf_release() accesses pipe->tmp_page
without taking any extra locks. From a glance through the callers of
pipe_buf_release(), it looks like FUSE is the only one that calls
pipe_buf_release() without having the pipe locked.

This bug should only lead to a memory leak, nothing terrible.

Fixes: dd3bb14f44 ("fuse: support splice() writing to fuse device")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-01-16 10:27:59 +01:00
Miklos Szeredi 8a3177db59 cuse: fix ioctl
cuse_process_init_reply() doesn't initialize fc->max_pages and thus all
cuse bases ioctls fail with ENOMEM.

Reported-by: Andreas Steinmetz <ast@domdv.de>
Fixes: 5da784cce4 ("fuse: add max_pages to init_out")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-01-16 10:27:59 +01:00
Miklos Szeredi 97e1532ef8 fuse: handle zero sized retrieve correctly
Dereferencing req->page_descs[0] will Oops if req->max_pages is zero.

Reported-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Tested-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Fixes: b2430d7567 ("fuse: add per-page descriptor <offset, length> to fuse_req")
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-01-16 10:27:59 +01:00
Arun KS ca79b0c211 mm: convert totalram_pages and totalhigh_pages variables to atomic
totalram_pages and totalhigh_pages are made static inline function.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:47 -08:00
Chad Austin 2e64ff154c fuse: continue to send FUSE_RELEASEDIR when FUSE_OPEN returns ENOSYS
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: 7678ac5061 ("fuse: support clients that don't implement 'open'")
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: Chad Austin <chadaustin@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-12-11 21:47:28 +01:00
Takeshi Misawa d72f70da60 fuse: Fix memory leak in fuse_dev_free()
When ntfs is unmounted, the following leak is
reported by kmemleak.

kmemleak report:

unreferenced object 0xffff880052bf4400 (size 4096):
  comm "mount.ntfs", pid 16530, jiffies 4294861127 (age 3215.836s)
  hex dump (first 32 bytes):
    00 44 bf 52 00 88 ff ff 00 44 bf 52 00 88 ff ff  .D.R.....D.R....
    10 44 bf 52 00 88 ff ff 10 44 bf 52 00 88 ff ff  .D.R.....D.R....
  backtrace:
    [<00000000bf4a2f8d>] fuse_fill_super+0xb22/0x1da0 [fuse]
    [<000000004dde0f0c>] mount_bdev+0x263/0x320
    [<0000000025aebc66>] mount_fs+0x82/0x2bf
    [<0000000042c5a6be>] vfs_kern_mount.part.33+0xbf/0x480
    [<00000000ed10cd5b>] do_mount+0x3de/0x2ad0
    [<00000000d59ff068>] ksys_mount+0xba/0xd0
    [<000000001bda1bcc>] __x64_sys_mount+0xba/0x150
    [<00000000ebe26304>] do_syscall_64+0x151/0x490
    [<00000000d25f2b42>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
    [<000000002e0abd2c>] 0xffffffffffffffff

fuse_dev_alloc() allocate fud->pq.processing.
But this hash table is not freed.

Fix this by freeing fud->pq.processing.

Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: be2ff42c5d ("fuse: Use hash table to link processing request")
2018-12-10 09:57:54 +01:00
Miklos Szeredi d233c7dd16 fuse: fix revalidation of attributes for permission check
fuse_invalidate_attr() now sets fi->inval_mask instead of fi->i_time, hence
we need to check the inval mask in fuse_permission() as well.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 2f1e81965f ("fuse: allow fine grained attr cache invaldation")
2018-12-03 10:14:43 +01:00
Miklos Szeredi a9c2d1e82f fuse: fix fsync on directory
Commit ab2257e994 ("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 <btgirton@gmail.com>
Tested-by: Brett Girton <btgirton@gmail.com>
Fixes: ab2257e994 ("fuse: reduce size of struct fuse_inode")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-12-03 10:14:43 +01:00
Myungho Jung 4fc4bb796b fuse: Add bad inode check in fuse_destroy_inode()
make_bad_inode() sets inode->i_mode to S_IFREG if I/O error is detected
in fuse_do_getattr()/fuse_do_setattr(). If the inode is not a regular
file, write_files and queued_writes in fuse_inode are not initialized
and have NULL or invalid pointers written by other members in a union.
So, list_empty() returns false in fuse_destroy_inode(). Add
is_bad_inode() to check if make_bad_inode() was called.

Reported-by: syzbot+b9c89b84423073226299@syzkaller.appspotmail.com
Fixes: ab2257e994 ("fuse: reduce size of struct fuse_inode")
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-11-22 10:20:19 +01:00
Lukas Czerner ebacb81273 fuse: fix use-after-free in fuse_direct_IO()
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 <lczerner@redhat.com>
Reported-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 744742d692 ("fuse: Add reference counting for fuse_io_priv")
Cc: <stable@vger.kernel.org> # v4.6
2018-11-09 15:52:17 +01:00
Miklos Szeredi 2d84a2d19b fuse: fix possibly missed wake-up after abort
In current fuse_drop_waiting() implementation it's possible that
fuse_wait_aborted() will not be woken up in the unlikely case that
fuse_abort_conn() + fuse_wait_aborted() runs in between checking
fc->connected and calling atomic_dec(&fc->num_waiting).

Do the atomic_dec_and_test() unconditionally, which also provides the
necessary barrier against reordering with the fc->connected check.

The explicit smp_mb() in fuse_wait_aborted() is not actually needed, since
the spin_unlock() in fuse_abort_conn() provides the necessary RELEASE
barrier after resetting fc->connected.  However, this is not a performance
sensitive path, and adding the explicit barrier makes it easier to
document.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: b8f95e5d13 ("fuse: umount should wait for all requests")
Cc: <stable@vger.kernel.org> #v4.19
2018-11-09 15:52:16 +01:00
Miklos Szeredi 7fabaf3034 fuse: fix leaked notify reply
fuse_request_send_notify_reply() may fail if the connection was reset for
some reason (e.g. fs was unmounted).  Don't leak request reference in this
case.  Besides leaking memory, this resulted in fc->num_waiting not being
decremented and hence fuse_wait_aborted() left in a hanging and unkillable
state.

Fixes: 2d45ba381a ("fuse: add retrieve request")
Fixes: b8f95e5d13 ("fuse: umount should wait for all requests")
Reported-and-tested-by: syzbot+6339eda9cb4ebbc4c37b@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> #v2.6.36
2018-11-09 15:52:16 +01:00
Linus Torvalds 9931a07d51 Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
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
  ...
2018-11-01 19:58:52 -07:00
David Howells 00e2370744 iov_iter: Use accessor function
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 <dhowells@redhat.com>
2018-10-24 00:40:44 +01:00
Dan Schatzberg 5571f1e654 fuse: enable caching of symlinks
FUSE file reads are cached in the page cache, but symlink reads are
not. This patch enables FUSE READLINK operations to be cached which
can improve performance of some FUSE workloads.

In particular, I'm working on a FUSE filesystem for access to source
code and discovered that about a 10% improvement to build times is
achieved with this patch (there are a lot of symlinks in the source
tree).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-15 15:43:07 +02:00
Miklos Szeredi 9a2eb24d1a fuse: only invalidate atime in direct read
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 <mszeredi@redhat.com>
2018-10-15 15:43:06 +02:00
Miklos Szeredi 802dc0497b fuse: don't need GETATTR after every READ
If 'auto_inval_data' mode is active, then fuse_file_read_iter() will call
fuse_update_attributes(), which will check the attribute validity and send
a GETATTR request if some of the attributes are no longer valid.  The page
cache is then invalidated if the size or mtime have changed.

Then, if a READ request was sent and reply received (which is the case if
the data wasn't cached yet, or if the file is opened for O_DIRECT), the
atime attribute is invalidated.

This will result in the next read() also triggering a GETATTR, ...

This can be fixed by only sending GETATTR if the mode or size are invalid,
we don't need to do a refresh if only atime is invalid.

More generally, none of the callers of fuse_update_attributes() need an
up-to-date atime value, so for now just remove STATX_ATIME from the request
mask when attributes are updated for internal use.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-15 15:43:06 +02:00
Miklos Szeredi 2f1e81965f fuse: allow fine grained attr cache invaldation
This patch adds the infrastructure for more fine grained attribute
invalidation.  Currently only 'atime' is invalidated separately.

The use of this infrastructure is extended to the statx(2) interface, which
for now means that if only 'atime' is invalid and STATX_ATIME is not
specified in the mask argument, then no GETATTR request will be generated.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-15 15:43:06 +02:00
Miklos Szeredi e52a825048 fuse: realloc page array
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 <mszeredi@redhat.com>
2018-10-01 10:07:06 +02:00
Constantine Shulyupin 5da784cce4 fuse: add max_pages to init_out
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 <const@MakeLinux.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:06 +02:00
Miklos Szeredi 8a7aa286ab fuse: allocate page array more efficiently
When allocating page array for a request the array for the page pointers
and the array for page descriptors are allocated by two separate kmalloc()
calls.  Merge these into one allocation.

Also instead of initializing the request and the page arrays with memset(),
use the zeroing allocation variants.

Reserved requests never carry pages (page array size is zero). Make that
explicit by initializing the page array pointers to NULL and make sure the
assumption remains true by adding a WARN_ON().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:05 +02:00
Miklos Szeredi ab2257e994 fuse: reduce size of struct fuse_inode
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 <mszeredi@redhat.com>
2018-10-01 10:07:05 +02:00
Miklos Szeredi 261aaba72f fuse: use iversion for readdir cache verification
Use the internal iversion counter to make sure modifications of the
directory through this filesystem are not missed by the mtime check (due to
mtime granularity).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:05 +02:00
Miklos Szeredi 7118883b44 fuse: use mtime for readdir cache verification
Store the modification time of the directory in the cache, obtained before
starting to fill the cache.

When reading the cache, verify that the directory hasn't changed, by
checking if current modification time is the same as the one stored in the
cache.

This only needs to be done when the current file position is at the
beginning of the directory, as mandated by POSIX.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi 3494927e09 fuse: add readdir cache version
Allow the cache to be invalidated when page(s) have gone missing.  In this
case increment the version of the cache and reset to an empty state.

Add a version number to the directory stream in struct fuse_file as well,
indicating the version of the cache it's supposed to be reading.  If the
cache version doesn't match the stream's version, then reset the stream to
the beginning of the cache.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi 5d7bc7e868 fuse: allow using readdir cache
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 <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi 69e3455115 fuse: allow caching readdir
This patch just adds the cache filling functions, which are invoked if
FOPEN_CACHE_DIR flag is set in the OPENDIR reply.

Cache reading and cache invalidation are added by subsequent patches.

The directory cache uses the page cache.  Directory entries are packed into
a page in the same format as in the READDIR reply.  A page only contains
whole entries, the space at the end of the page is cleared.  The page is
locked while being modified.

Multiple parallel readdirs on the same directory can fill the cache; the
only constraint is that continuity must be maintained (d_off of last entry
points to position of current entry).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01 10:07:04 +02:00
Miklos Szeredi 18172b10b6 fuse: extract fuse_emit() helper
Prepare for cache filling by introducing a helper for emitting a single
directory entry.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Miklos Szeredi d123d8e183 fuse: split out readdir.c
Directory reading code is about to grow larger, so split it out from dir.c
into a new source file.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Kirill Tkhai be2ff42c5d fuse: Use hash table to link processing request
We noticed the performance bottleneck in FUSE running our Virtuozzo storage
over rdma. On some types of workload we observe 20% of times spent in
request_find() in profiler.  This function is iterating over long requests
list, and it scales bad.

The patch introduces hash table to reduce the number of iterations, we do
in this function. Hash generating algorithm is taken from hash_add()
function, while 256 lines table is used to store pending requests.  This
fixes problem and improves the performance.

Reported-by: Alexey Kuznetsov <kuznet@virtuozzo.com>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Kirill Tkhai 3a5358d1a1 fuse: kill req->intr_unique
This field is not needed after the previous patch, since we can easily
convert request ID to interrupt request ID and vice versa.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Kirill Tkhai c59fd85e4f fuse: change interrupt requests allocation algorithm
Using of two unconnected IDs req->in.h.unique and req->intr_unique does not
allow to link requests to a hash table. We need can't use none of them as a
key to calculate hash.

This patch changes the algorithm of allocation of IDs for a request. Plain
requests obtain even ID, while interrupt requests are encoded in the low
bit. So, in next patches we will be able to use the rest of ID bits to
calculate hash, and the hash will be the same for plain and interrupt
requests.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Kirill Tkhai 63825b4e1d fuse: do not take fc->lock in fuse_request_send_background()
Currently, we take fc->lock there only to check for fc->connected.
But this flag is changed only on connection abort, which is very
rare operation.

So allow checking fc->connected under just fc->bg_lock and use this lock
(as well as fc->lock) when resetting fc->connected.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:23 +02:00
Kirill Tkhai ae2dffa394 fuse: introduce fc->bg_lock
To reduce contention of fc->lock, this patch introduces bg_lock for
protection of fields related to background queue. These are:
max_background, congestion_threshold, num_background, active_background,
bg_queue and blocked.

This allows next patch to make async reads not requiring fc->lock, so async
reads and writes will have better performance executed in parallel.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:22 +02:00
Kirill Tkhai 2b30a53314 fuse: add locking to max_background and congestion_threshold changes
Functions sequences like request_end()->flush_bg_queue() require that
max_background and congestion_threshold are constant during their
execution. Otherwise, checks like

	if (fc->num_background == fc->max_background)

made in different time may behave not like expected.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:22 +02:00
Kirill Tkhai 2a23f2b8ad fuse: use READ_ONCE on congestion_threshold and max_background
Since they are of unsigned int type, it's allowed to read them
unlocked during reporting to userspace. Let's underline this fact
with READ_ONCE() macroses.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:22 +02:00
Kirill Tkhai e287179afe fuse: use list_first_entry() in flush_bg_queue()
This cleanup patch makes the function to use the primitive
instead of direct dereferencing.

Also, move fiq dereferencing out of cycle, since it's
always constant.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:22 +02:00
Niels de Vos 88bc7d5097 fuse: add support for copy_file_range()
There are several FUSE filesystems that can implement server-side copy
or other efficient copy/duplication/clone methods. The copy_file_range()
syscall is the standard interface that users have access to while not
depending on external libraries that bypass FUSE.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28 16:43:22 +02:00
Miklos Szeredi 908a572b80 fuse: fix blocked_waitq wakeup
Using waitqueue_active() is racy.  Make sure we issue a wake_up()
unconditionally after storing into fc->blocked.  After that it's okay to
optimize with waitqueue_active() since the first wake up provides the
necessary barrier for all waiters, not the just the woken one.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 3c18ef8117 ("fuse: optimize wake_up")
Cc: <stable@vger.kernel.org> # v3.10
2018-09-28 16:43:22 +02:00
Miklos Szeredi 4c316f2f3f fuse: set FR_SENT while locked
Otherwise fuse_dev_do_write() could come in and finish off the request, and
the set_bit(FR_SENT, ...) could trigger the WARN_ON(test_bit(FR_SENT, ...))
in request_end().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reported-by: syzbot+ef054c4d3f64cd7f7cec@syzkaller.appspotmai
Fixes: 46c34a348b ("fuse: no fc->lock for pqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
2018-09-28 16:43:22 +02:00
Kirill Tkhai d2d2d4fb1f fuse: Fix use-after-free in fuse_dev_do_write()
After we found req in request_find() and released the lock,
everything may happen with the req in parallel:

cpu0                              cpu1
fuse_dev_do_write()               fuse_dev_do_write()
  req = request_find(fpq, ...)    ...
  spin_unlock(&fpq->lock)         ...
  ...                             req = request_find(fpq, oh.unique)
  ...                             spin_unlock(&fpq->lock)
  queue_interrupt(&fc->iq, req);   ...
  ...                              ...
  ...                              ...
  request_end(fc, req);
    fuse_put_request(fc, req);
  ...                              queue_interrupt(&fc->iq, req);


Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 46c34a348b ("fuse: no fc->lock for pqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
2018-09-28 16:43:21 +02:00
Kirill Tkhai bc78abbd55 fuse: Fix use-after-free in fuse_dev_do_read()
We may pick freed req in this way:

[cpu0]                                  [cpu1]
fuse_dev_do_read()                      fuse_dev_do_write()
   list_move_tail(&req->list, ...);     ...
   spin_unlock(&fpq->lock);             ...
   ...                                  request_end(fc, req);
   ...                                    fuse_put_request(fc, req);
   if (test_bit(FR_INTERRUPTED, ...))
         queue_interrupt(fiq, req);

Fix that by keeping req alive until we finish all manipulations.

Reported-by: syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 46c34a348b ("fuse: no fc->lock for pqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
2018-09-28 16:43:21 +02:00
Linus Torvalds ad1d697358 fuse update for 4.19
This contains various bug fixes and cleanups.
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Merge tag 'fuse-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse update from Miklos Szeredi:
 "Various bug fixes and cleanups"

* tag 'fuse-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: reduce allocation size for splice_write
  fuse: use kvmalloc to allocate array of pipe_buffer structs.
  fuse: convert last timespec use to timespec64
  fs: fuse: Adding new return type vm_fault_t
  fuse: simplify fuse_abort_conn()
  fuse: Add missed unlock_page() to fuse_readpages_fill()
  fuse: Don't access pipe->buffers without pipe_lock()
  fuse: fix initial parallel dirops
  fuse: Fix oops at process_init_reply()
  fuse: umount should wait for all requests
  fuse: fix unlocked access to processing queue
  fuse: fix double request_end()
2018-08-21 18:47:36 -07:00
Linus Torvalds 0214f46b3a Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...
2018-08-21 13:47:29 -07:00
Linus Torvalds 0ea97a2d61 Merge branch 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs icache updates from Al Viro:

 - NFS mkdir/open_by_handle race fix

 - analogous solution for FUSE, replacing the one currently in mainline

 - new primitive to be used when discarding halfway set up inodes on
   failed object creation; gives sane warranties re icache lookups not
   returning such doomed by still not freed inodes. A bunch of
   filesystems switched to that animal.

 - Miklos' fix for last cycle regression in iget5_locked(); -stable will
   need a slightly different variant, unfortunately.

 - misc bits and pieces around things icache-related (in adfs and jfs).

* 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jfs: don't bother with make_bad_inode() in ialloc()
  adfs: don't put inodes into icache
  new helper: inode_fake_hash()
  vfs: don't evict uninitialized inode
  jfs: switch to discard_new_inode()
  ext2: make sure that partially set up inodes won't be returned by ext2_iget()
  udf: switch to discard_new_inode()
  ufs: switch to discard_new_inode()
  btrfs: switch to discard_new_inode()
  new primitive: discard_new_inode()
  kill d_instantiate_no_diralias()
  nfs_instantiate(): prevent multiple aliases for directory inode
2018-08-13 20:25:58 -07:00
Al Viro c971e6a006 kill d_instantiate_no_diralias()
The only user is fuse_create_new_entry(), and there it's used to
mitigate the same mkdir/open-by-handle race as in nfs_mkdir().
The same solution applies - unhash the mkdir argument, then
call d_splice_alias() and if that returns a reference to preexisting
alias, dput() and report success.  ->mkdir() argument left unhashed
negative with the preexisting alias moved in the right place is just
fine from the ->mkdir() callers point of view.

Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-01 23:18:53 -04:00
Andrey Ryabinin 9635453572 fuse: reduce allocation size for splice_write
The 'bufs' array contains 'pipe->buffers' elements, but the
fuse_dev_splice_write() uses only 'pipe->nrbufs' elements.

So reduce the allocation size to 'pipe->nrbufs' elements.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26 16:13:12 +02:00
Andrey Ryabinin d6d931adce fuse: use kvmalloc to allocate array of pipe_buffer structs.
The amount of pipe->buffers is basically controlled by userspace by
fcntl(... F_SETPIPE_SZ ...) so it could be large. High order allocations
could be slow (if memory is heavily fragmented) or may fail if the order
is larger than PAGE_ALLOC_COSTLY_ORDER.

Since the 'bufs' doesn't need to be physically contiguous, use
the kvmalloc_array() to allocate memory. If high order
page isn't available, the kvamalloc*() will fallback to 0-order.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26 16:13:12 +02:00
Arnd Bergmann a64ba10f65 fuse: convert last timespec use to timespec64
All of fuse uses 64-bit timestamps with the exception of the
fuse_change_attributes(), so let's convert this one as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26 16:13:12 +02:00