Commit Graph

323 Commits

Author SHA1 Message Date
Linus Torvalds
a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Al Viro
c71d227fc4 make kernel-side POLL... arch-independent
mangle/demangle on the way to/from userland

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-29 19:00:41 -05:00
Al Viro
076ccb76e1 fs: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:20:05 -05:00
Linus Torvalds
e7989f973a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
 "This fixes a regression (spotted by the Sandstorm.io folks) in the pid
  namespace handling introduced in 4.12.

  There's also a fix for honoring sync/dsync flags for pwritev2()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: getattr cleanup
  fuse: honor iocb sync flags on write
  fuse: allow server to run in different pid_ns
2017-09-13 10:10:19 -07:00
Miklos Szeredi
5b97eeacbd fuse: getattr cleanup
The refreshed argument isn't used by any caller, get rid of it.

Use a helper for just updating the inode (no need to fill in a kstat).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-12 16:57:54 +02:00
Miklos Szeredi
e1c0eecba1 fuse: honor iocb sync flags on write
If the IOCB_DSYNC flag is set a sync is not being performed by
fuse_file_write_iter.

Honor IOCB_DSYNC/IOCB_SYNC by setting O_DYSNC/O_SYNC respectively in the
flags filed of the write request.

We don't need to sync data or metadata, since fuse_perform_write() does
write-through and the filesystem is responsible for updating file times.

Original patch by Vitaly Zolotusky.

Reported-by: Nate Clark <nate@neworld.us>
Cc: Vitaly Zolotusky <vitaly@unitc.com>.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-12 16:57:53 +02:00
Miklos Szeredi
5d6d3a301c fuse: allow server to run in different pid_ns
Commit 0b6e9ea041 ("fuse: Add support for pid namespaces") broke
Sandstorm.io development tools, which have been sending FUSE file
descriptors across PID namespace boundaries since early 2014.

The above patch added a check that prevented I/O on the fuse device file
descriptor if the pid namespace of the reader/writer was different from the
pid namespace of the mounter.  With this change passing the device file
descriptor to a different pid namespace simply doesn't work.  The check was
added because pids are transferred to/from the fuse userspace server in the
namespace registered at mount time.

To fix this regression, remove the checks and do the following:

1) the pid in the request header (the pid of the task that initiated the
filesystem operation) is translated to the reader's pid namespace.  If a
mapping doesn't exist for this pid, then a zero pid is used.  Note: even if
a mapping would exist between the initiator task's pid namespace and the
reader's pid namespace the pid will be zero if either mapping from
initator's to mounter's namespace or mapping from mounter's to reader's
namespace doesn't exist.

2) The lk.pid value in setlk/setlkw requests and getlk reply is left alone.
Userspace should not interpret this value anyway.  Also allow the
setlk/setlkw operations if the pid of the task cannot be represented in the
mounter's namespace (pid being zero in that case).

Reported-by: Kenton Varda <kenton@sandstorm.io>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 0b6e9ea041 ("fuse: Add support for pid namespaces")
Cc: <stable@vger.kernel.org> # v4.12+
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
2017-09-12 16:57:53 +02:00
Linus Torvalds
ec3604c7a5 Writeback error handling fixes for v4.14
-----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJZrTy3AAoJEAAOaEEZVoIVaucP/ApBAj2S5wzvlV1u6l8E6ae7
 ZeEEZfcWwzRYlKjZAkTWqj9XvGpDGO5gLq4wsZK2edFAq++/MJF8ZVtN4tdZ1kUZ
 DUvRodtVOrT08Kp9wZXGT7JOFrf6U/6gMcR6p0MuWnHndeKYvlpcFi9NPT4EC9/z
 Zm9V7gtlPdSOha7eaSjUS0+vLERkxqXLBW3Av9QUOBP/lbI3lqIroGKeHDYnVdya
 2P/k5EcRRJMyJP6TqyYxmmJl+UWjJFMLvnlUDBslHnD/u3mIUhw3JLHYBjn5dZRE
 Xjq56IDPoXDUvzlBhtn/Uqyx+/wtwsNsylpmKv6K5G1JfdeuSsPVsCey+A1cqV64
 LpE5896wf9TmnmI9LNyh6vDn925xPSGBiF45UEp5f9aO7jXeY0MaEZ8g+ENqFIDK
 v4gtZdS9FhYHV+/l4qEwYMKrqSbwKEs1r1FT+f4wnABby1ojfdA57ZPlp5PV2Vjp
 szTp88Zkb7cMvZwEnWwxWofcJNmgS7uNahvnQF3IJ4ITsioEkuyYR3K4ZQMaaaV9
 wCp6G0FhXZaK3OI7o9WiDwaO2elp9Hxc8bnqKpiBbHZkY0NLh7/++5VxpeNbTHFy
 AGijQiiKGNNyYqNj93wq9jpVdMNjB0pXrHRxfav8v7MtQ+WfbEoAENF4T7hN7iXn
 UuF6eSWEC5O1UCRUk1A+
 =LLY3
 -----END PGP SIGNATURE-----

Merge tag 'wberr-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull writeback error handling updates from Jeff Layton:
 "This pile continues the work from last cycle on better tracking
  writeback errors. In v4.13 we added some basic errseq_t infrastructure
  and converted a few filesystems to use it.

  This set continues refining that infrastructure, adds documentation,
  and converts most of the other filesystems to use it. The main
  exception at this point is the NFS client"

* tag 'wberr-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  ecryptfs: convert to file_write_and_wait in ->fsync
  mm: remove optimizations based on i_size in mapping writeback waits
  fs: convert a pile of fsync routines to errseq_t based reporting
  gfs2: convert to errseq_t based writeback error reporting for fsync
  fs: convert sync_file_range to use errseq_t based error-tracking
  mm: add file_fdatawait_range and file_write_and_wait
  fuse: convert to errseq_t based error tracking for fsync
  mm: consolidate dax / non-dax checks for writeback
  Documentation: add some docs for errseq_t
  errseq: rename __errseq_set to errseq_set
2017-09-06 14:11:03 -07:00
Linus Torvalds
066dea8c30 File locking related changes for v4.14
-----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJZrTzyAAoJEAAOaEEZVoIVj8wP/0sOxG+7vEEpe4uj2W52aq9T
 Y39/ZLfRTLm9SqgH61lkN+IyUsvDx+IP1ws2LBhp0IDRD9m40wdILhHZRWXJcRW2
 ApEfmXF+rxnZZ6725ixX9w4Ylab2ZeGmKbzaG4wIjxfddftewZkJvFQcb1LZDfWq
 1N0SF4KWoWN6t26Du5CHmYSj/Sz6YGrWGhF22u3mNfkGL+MmuKbz+kB3W+0q2NUF
 ZjkOIH9WcRiXgSlcHPBLre2EKHqHaNgb0s4Iofd3ZEe50v1NwY/vBMefxuwRdgKS
 kpLhIKIYMawrHn2rpV0jm12qdgCYj+t2kbVIUBDn3unBP2zYA0e/oo5HNIrroVlk
 Q6aGwmW0LN60rpd5qcRuNS1p1h2id2HpxEe98dsski6T8CVnj/nvu7EIxmWM02cf
 g2HeOd7bnl3+uu7SwSTkOVb6G7Kjn+Xufiz/n11mK6fl2jvOyWZZmDqhhjWAYJ8r
 t5mQVWJdEV12+6+A1WSv9DeS3TUgdYPCF8dzDtF+JVn3WEmxYHywH36Y3hKKz+BA
 gFEhnHvlyaVvpXCr8Y5BqNSfEfvZe/YUnmVReHpgBU/U4GJ17iQYk/g2vfmPLmsN
 IZ2OGCrDUc/LfdWc4llRyQBvlGT1KujaT0tbN7xnuWcS2qWdsfX4jDtDUH9E6pvK
 TB6Sw4Ike0ixamG8N8q/
 =VPMU
 -----END PGP SIGNATURE-----

Merge tag 'locks-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull file locking updates from Jeff Layton:
 "This pile just has a few file locking fixes from Ben Coddington. There
  are a couple of cleanup patches + an attempt to bring sanity to the
  l_pid value that is reported back to userland on an F_GETLK request.

  After a few gyrations, he came up with a way for filesystems to
  communicate to the VFS layer code whether the pid should be translated
  according to the namespace or presented as-is to userland"

* tag 'locks-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  locks: restore a warn for leaked locks on close
  fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks
  fs/locks: Use allocation rather than the stack in fcntl_getlk()
2017-09-06 13:43:26 -07:00
Jeff Layton
9183976ef1 fuse: set mapping error in writepage_locked when it fails
This ensures that we see errors on fsync when writeback fails.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-08-11 11:38:26 +02:00
Ashish Samant
61c12b49e1 fuse: Dont call set_page_dirty_lock() for ITER_BVEC pages for async_dio
Commit 8fba54aebb ("fuse: direct-io: don't dirty ITER_BVEC pages") fixes
the ITER_BVEC page deadlock for direct io in fuse by checking in
fuse_direct_io(), whether the page is a bvec page or not, before locking
it.  However, this check is missed when the "async_dio" mount option is
enabled.  In this case, set_page_dirty_lock() is called from the req->end
callback in request_end(), when the fuse thread is returning from userspace
to respond to the read request.  This will cause the same deadlock because
the bvec condition is not checked in this path.

Here is the stack of the deadlocked thread, while returning from userspace:

[13706.656686] INFO: task glusterfs:3006 blocked for more than 120 seconds.
[13706.657808] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[13706.658788] glusterfs       D ffffffff816c80f0     0  3006      1
0x00000080
[13706.658797]  ffff8800d6713a58 0000000000000086 ffff8800d9ad7000
ffff8800d9ad5400
[13706.658799]  ffff88011ffd5cc0 ffff8800d6710008 ffff88011fd176c0
7fffffffffffffff
[13706.658801]  0000000000000002 ffffffff816c80f0 ffff8800d6713a78
ffffffff816c790e
[13706.658803] Call Trace:
[13706.658809]  [<ffffffff816c80f0>] ? bit_wait_io_timeout+0x80/0x80
[13706.658811]  [<ffffffff816c790e>] schedule+0x3e/0x90
[13706.658813]  [<ffffffff816ca7e5>] schedule_timeout+0x1b5/0x210
[13706.658816]  [<ffffffff81073ffb>] ? gup_pud_range+0x1db/0x1f0
[13706.658817]  [<ffffffff810668fe>] ? kvm_clock_read+0x1e/0x20
[13706.658819]  [<ffffffff81066909>] ? kvm_clock_get_cycles+0x9/0x10
[13706.658822]  [<ffffffff810f5792>] ? ktime_get+0x52/0xc0
[13706.658824]  [<ffffffff816c6f04>] io_schedule_timeout+0xa4/0x110
[13706.658826]  [<ffffffff816c8126>] bit_wait_io+0x36/0x50
[13706.658828]  [<ffffffff816c7d06>] __wait_on_bit_lock+0x76/0xb0
[13706.658831]  [<ffffffffa0545636>] ? lock_request+0x46/0x70 [fuse]
[13706.658834]  [<ffffffff8118800a>] __lock_page+0xaa/0xb0
[13706.658836]  [<ffffffff810c8500>] ? wake_atomic_t_function+0x40/0x40
[13706.658838]  [<ffffffff81194d08>] set_page_dirty_lock+0x58/0x60
[13706.658841]  [<ffffffffa054d968>] fuse_release_user_pages+0x58/0x70 [fuse]
[13706.658844]  [<ffffffffa0551430>] ? fuse_aio_complete+0x190/0x190 [fuse]
[13706.658847]  [<ffffffffa0551459>] fuse_aio_complete_req+0x29/0x90 [fuse]
[13706.658849]  [<ffffffffa05471e9>] request_end+0xd9/0x190 [fuse]
[13706.658852]  [<ffffffffa0549126>] fuse_dev_do_write+0x336/0x490 [fuse]
[13706.658854]  [<ffffffffa054963e>] fuse_dev_write+0x6e/0xa0 [fuse]
[13706.658857]  [<ffffffff812a9ef3>] ? security_file_permission+0x23/0x90
[13706.658859]  [<ffffffff81205300>] do_iter_readv_writev+0x60/0x90
[13706.658862]  [<ffffffffa05495d0>] ? fuse_dev_splice_write+0x350/0x350
[fuse]
[13706.658863]  [<ffffffff812062a1>] do_readv_writev+0x171/0x1f0
[13706.658866]  [<ffffffff810b3d00>] ? try_to_wake_up+0x210/0x210
[13706.658868]  [<ffffffff81206361>] vfs_writev+0x41/0x50
[13706.658870]  [<ffffffff81206496>] SyS_writev+0x56/0xf0
[13706.658872]  [<ffffffff810257a1>] ? syscall_trace_leave+0xf1/0x160
[13706.658874]  [<ffffffff816cbb2e>] system_call_fastpath+0x12/0x71

Fix this by making should_dirty a fuse_io_priv parameter that can be
checked in fuse_aio_complete_req().

Reported-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-08-03 17:55:58 +02:00
Jeff Layton
7e51fe1dd1 fuse: convert to errseq_t based error tracking for fsync
Change to file_write_and_wait_range and
file_check_and_advance_wb_err

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-31 19:12:25 -04:00
Benjamin Coddington
9d5b86ac13 fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks
Since commit c69899a17c "NFSv4: Update of VFS byte range lock must be
atomic with the stateid update", NFSv4 has been inserting locks in rpciod
worker context.  The result is that the file_lock's fl_nspid is the
kworker's pid instead of the original userspace pid.

The fl_nspid is only used to represent the namespaced virtual pid number
when displaying locks or returning from F_GETLK.  There's no reason to set
it for every inserted lock, since we can usually just look it up from
fl_pid.  So, instead of looking up and holding struct pid for every lock,
let's just look up the virtual pid number from fl_pid when it is needed.
That means we can remove fl_nspid entirely.

The translaton and presentation of fl_pid should handle the following four
cases:

1 - F_GETLK on a remote file with a remote lock:
    In this case, the filesystem should determine the l_pid to return here.
    Filesystems should indicate that the fl_pid represents a non-local pid
    value that should not be translated by returning an fl_pid <= 0.

2 - F_GETLK on a local file with a remote lock:
    This should be the l_pid of the lock manager process, and translated.

3 - F_GETLK on a remote file with a local lock, and
4 - F_GETLK on a local file with a local lock:
    These should be the translated l_pid of the local locking process.

Fuse was already doing the correct thing by translating the pid into the
caller's namespace.  With this change we must update fuse to translate
to init's pid namespace, so that the locks API can then translate from
init's pid namespace into the pid namespace of the caller.

With this change, the locks API will expect that if a filesystem returns
a remote pid as opposed to a local pid for F_GETLK, that remote pid will
be <= 0.  This signifies that the pid is remote, and the locks API will
forego translating that pid into the pid namespace of the local calling
process.

Finally, we convert remote filesystems to present remote pids using
negative numbers. Have lustre, 9p, ceph, cifs, and dlm negate the remote
pid returned for F_GETLK lock requests.

Since local pids will never be larger than PID_MAX_LIMIT (which is
currently defined as <= 4 million), but pid_t is an unsigned int, we
should have plenty of room to represent remote pids with negative
numbers if we assume that remote pid numbers are similarly limited.

If this is not the case, then we run the risk of having a remote pid
returned for which there is also a corresponding local pid.  This is a
problem we have now, but this patch should reduce the chances of that
occurring, while also returning those remote pid numbers, for whatever
that may be worth.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-16 10:28:22 -04:00
Mateusz Jurczyk
68227c03cb fuse: initialize the flock flag in fuse_file on allocation
Before the patch, the flock flag could remain uninitialized for the
lifespan of the fuse_file allocation. Unless set to true in
fuse_file_flock(), it would remain in an indeterminate state until read in
an if statement in fuse_release_common(). This could consequently lead to
taking an unexpected branch in the code.

The bug was discovered by a runtime instrumentation designed to detect use
of uninitialized memory in the kernel.

Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Fixes: 37fb3a30b4 ("fuse: fix flock")
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-06-09 11:16:22 +02:00
Linus Torvalds
73ccb023a2 NFS client updates for Linux 4.12
Highlights include:
 
 Stable bugfixes:
 - Fix use after free in write error path
 - Use GFP_NOIO for two allocations in writeback
 - Fix a hang in OPEN related to server reboot
 - Check the result of nfs4_pnfs_ds_connect
 - Fix an rcu lock leak
 
 Features:
 - Removal of the unmaintained and unused OSD pNFS layout
 - Cleanup and removal of lots of unnecessary dprintk()s
 - Cleanup and removal of some memory failure paths now that
   GFP_NOFS is guaranteed to never fail.
 - Remove the v3-only data server limitation on pNFS/flexfiles
 
 Bugfixes:
 - RPC/RDMA connection handling bugfixes
 - Copy offload: fixes to ensure the copied data is COMMITed to disk.
 - Readdir: switch back to using the ->iterate VFS interface
 - File locking fixes from Ben Coddington
 - Various use-after-free and deadlock issues in pNFS
 - Write path bugfixes
 -----BEGIN PGP SIGNATURE-----
 
 iQIbBAABAgAGBQJZE0KiAAoJEGcL54qWCgDy/moP93wZ+cGnN5sC+nsirqj4eUiM
 BQKKonweNQIoYRwp5B9jLTxsUMIxRasV5W3BbqEm4PUtBYXfqQ7SfLv7RboKbd4M
 RJB9PS+sjx3Fxf65mhveKziwUFLvQCQ3+we0TpUga6+7SBiGlgPKBfisk7frC0nt
 BbYBuGaWXMPxO0BnR8adNwqiGINPDSzB+8sgjiT8zkZLm4lrew2eV7TDvwVOguD+
 S2vLPGhg1F9wu8aG731MgiSNaeCgsBP6I5D29fTTD7z1DCNMQXOoHcX8k4KwwIDB
 sHRR0tVBsg+1B7WdH4y41GQ03rn3o2DHeJB5cdYGaEu4lx7CecCzt0o0dfAkNizT
 5LxbQxIHPNYMeZmP2T0oD41zQyfjKqrdRSPnXi3dPD98NwaM1Lqv+Kzb/eXzupXp
 vJ7859PQCa3KjQ1IFhwdXTmh53J1c8SzEDpzz7WX0R0saRyxeIJsm30MmdPqKu7Z
 notjsXxrTmjIhC+0vFLey1kejFDh+b0gT6UIwoMdx39VL9AM6DVL7HsrU1kEwCdf
 f8otaLcm0WoUaseF+cMtfRNGEqCMxPywwz7mEKlGiVZgyAM8VfzH+s5j6/u6ncwS
 ASwRclwwPAZN97rzl0exZxuaRwFZd7oFT1zrviPWvv+0SUPuy258J6QpolUSavgi
 Qh7f3QR65K+QX9QbO1g=
 =7Nm2
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable bugfixes:
   - Fix use after free in write error path
   - Use GFP_NOIO for two allocations in writeback
   - Fix a hang in OPEN related to server reboot
   - Check the result of nfs4_pnfs_ds_connect
   - Fix an rcu lock leak

  Features:
   - Removal of the unmaintained and unused OSD pNFS layout
   - Cleanup and removal of lots of unnecessary dprintk()s
   - Cleanup and removal of some memory failure paths now that GFP_NOFS
     is guaranteed to never fail.
   - Remove the v3-only data server limitation on pNFS/flexfiles

  Bugfixes:
   - RPC/RDMA connection handling bugfixes
   - Copy offload: fixes to ensure the copied data is COMMITed to disk.
   - Readdir: switch back to using the ->iterate VFS interface
   - File locking fixes from Ben Coddington
   - Various use-after-free and deadlock issues in pNFS
   - Write path bugfixes"

* tag 'nfs-for-4.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (89 commits)
  pNFS/flexfiles: Always attempt to call layoutstats when flexfiles is enabled
  NFSv4.1: Work around a Linux server bug...
  NFS append COMMIT after synchronous COPY
  NFSv4: Fix exclusive create attributes encoding
  NFSv4: Fix an rcu lock leak
  nfs: use kmap/kunmap directly
  NFS: always treat the invocation of nfs_getattr as cache hit when noac is on
  Fix nfs_client refcounting if kmalloc fails in nfs4_proc_exchange_id and nfs4_proc_async_renew
  NFSv4.1: RECLAIM_COMPLETE must handle NFS4ERR_CONN_NOT_BOUND_TO_SESSION
  pNFS: Fix NULL dereference in pnfs_generic_alloc_ds_commits
  pNFS: Fix a typo in pnfs_generic_alloc_ds_commits
  pNFS: Fix a deadlock when coalescing writes and returning the layout
  pNFS: Don't clear the layout return info if there are segments to return
  pNFS: Ensure we commit the layout if it has been invalidated
  pNFS: Don't send COMMITs to the DSes if the server invalidated our layout
  pNFS/flexfiles: Fix up the ff_layout_write_pagelist failure path
  pNFS: Ensure we check layout validity before marking it for return
  NFS4.1 handle interrupted slot reuse from ERR_DELAY
  NFSv4: check return value of xdr_inline_decode
  nfs/filelayout: fix NULL pointer dereference in fl_pnfs_update_layout()
  ...
2017-05-10 13:03:38 -07:00
Benjamin Coddington
50f2112cf7 locks: Set FL_CLOSE when removing flock locks on close()
Set FL_CLOSE in fl_flags as in locks_remove_posix() when clearing locks.
NFS will check for this flag to ensure an unlock is sent in a following
patch.

Fuse handles flock and posix locks differently for FL_CLOSE, and so
requires a fixup to retain the existing behavior for flock.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-04-21 10:45:01 -04:00
Seth Forshee
0b6e9ea041 fuse: Add support for pid namespaces
When the userspace process servicing fuse requests is running in
a pid namespace then pids passed via the fuse fd are not being
translated into that process' namespace. Translation is necessary
for the pid to be useful to that process.

Since no use case currently exists for changing namespaces all
translations can be done relative to the pid namespace in use
when fuse_conn_init() is called. For fuse this translates to
mount time, and for cuse this is when /dev/cuse is opened. IO for
this connection from another namespace will return errors.

Requests from processes whose pid cannot be translated into the
target namespace will have a value of 0 for in.h.pid.

File locking changes based on previous work done by Eric
Biederman.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-04-18 16:58:38 +02:00
Elena Reshetova
4e8c2eb543 fuse: convert fuse_file.count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-04-18 16:58:37 +02:00
Linus Torvalds
4e66c42c60 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse update from Miklos Szeredi:
 "A bugfix and cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: release: private_data cannot be NULL
  fuse: cleanup fuse_file refcounting
  fuse: add missing FR_FORCE
2017-03-03 12:14:13 -08:00
Dave Jiang
11bac80004 mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.

Remove the vma parameter to simplify things.

[arnd@arndb.de: fix ARM build]
  Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
Miklos Szeredi
9a87ad3da9 fuse: release: private_data cannot be NULL
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-02-22 20:08:25 +01:00
Miklos Szeredi
267d84449f fuse: cleanup fuse_file refcounting
struct fuse_file is stored in file->private_data.  Make this always be a
counting reference for consistency.

This also allows fuse_sync_release() to call fuse_file_put() instead of
partially duplicating its functionality.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-02-22 20:08:25 +01:00
Miklos Szeredi
2e38bea99a fuse: add missing FR_FORCE
fuse_file_put() was missing the "force" flag for the RELEASE request when
sending synchronously (fuseblk).

If this flag is not set, then a sync request may be interrupted before it
is dequeued by the userspace filesystem.  In this case the OPEN won't be
balanced with a RELEASE.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 5a18ec176c ("fuse: fix hang of single threaded fuseblk filesystem")
Cc: <stable@vger.kernel.org> # v2.6.38+
2017-02-22 20:08:25 +01:00
Miklos Szeredi
59c3b76cc6 fuse: fix fuse_write_end() if zero bytes were copied
If pos is at the beginning of a page and copied is zero then page is not
zeroed but is marked uptodate.

Fix by skipping everything except unlock/put of page if zero bytes were
copied.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 6b12c1b37e ("fuse: Implement write_begin/write_end callbacks")
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-11-15 12:34:21 +01:00
Linus Torvalds
abb5a14fa2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted misc bits and pieces.

  There are several single-topic branches left after this (rename2
  series from Miklos, current_time series from Deepa Dinamani, xattr
  series from Andreas, uaccess stuff from from me) and I'd prefer to
  send those separately"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
  proc: switch auxv to use of __mem_open()
  hpfs: support FIEMAP
  cifs: get rid of unused arguments of CIFSSMBWrite()
  posix_acl: uapi header split
  posix_acl: xattr representation cleanups
  fs/aio.c: eliminate redundant loads in put_aio_ring_file
  fs/internal.h: add const to ns_dentry_operations declaration
  compat: remove compat_printk()
  fs/buffer.c: make __getblk_slow() static
  proc: unsigned file descriptors
  fs/file: more unsigned file descriptors
  fs: compat: remove redundant check of nr_segs
  cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
  cifs: don't use memcpy() to copy struct iov_iter
  get rid of separate multipage fault-in primitives
  fs: Avoid premature clearing of capabilities
  fs: Give dentry to inode_change_ok() instead of inode
  fuse: Propagate dentry down to inode_change_ok()
  ceph: Propagate dentry down to inode_change_ok()
  xfs: Propagate dentry down to inode_change_ok()
  ...
2016-10-10 13:04:49 -07:00
Al Viro
e55f1d1d13 Merge remote-tracking branch 'jk/vfs' into work.misc 2016-10-08 11:06:08 -04:00
Miklos Szeredi
acbe5fda1f fuse: don't use fuse_ioctl_copy_user() helper
The two invocations share little code.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01 07:32:33 +02:00
Al Viro
3daa9c5165 fuse_ioctl_copy_user(): don't open-code copy_page_{to,from}_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01 07:32:33 +02:00
Jan Kara
6249033076 fuse: Propagate dentry down to inode_change_ok()
To avoid clearing of capabilities or security related extended
attributes too early, inode_change_ok() will need to take dentry instead
of inode. Propagate it down to fuse_do_setattr().

Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2016-09-22 10:56:19 +02:00
Miklos Szeredi
8fba54aebb fuse: direct-io: don't dirty ITER_BVEC pages
When reading from a loop device backed by a fuse file it deadlocks on
lock_page().

This is because the page is already locked by the read() operation done on
the loop device.  In this case we don't want to either lock the page or
dirty it.

So do what fs/direct-io.c does: only dirty the page for ITER_IOVEC vectors.

Reported-by: Sheng Yang <sheng@yasker.org>
Fixes: aa4d86163e ("block: loop: switch to VFS ITER_BVEC")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.1+
Reviewed-by: Sheng Yang <sheng@yasker.org>
Reviewed-by: Ashish Samant <ashish.samant@oracle.com>
Tested-by: Sheng Yang <sheng@yasker.org>
Tested-by: Ashish Samant <ashish.samant@oracle.com>
2016-08-24 18:17:04 +02:00
Linus Torvalds
27ae0c41ed Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
 "This fixes error propagation from writeback to fsync/close for
  writeback cache mode as well as adding a missing capability flag to
  the INIT message.  The rest are cleanups.

  (The commits are recent but all the code actually sat in -next for a
  while now.  The recommits are due to conflict avoidance and the
  addition of Cc: stable@...)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: use filemap_check_errors()
  mm: export filemap_check_errors() to modules
  fuse: fix wrong assignment of ->flags in fuse_send_init()
  fuse: fuse_flush must check mapping->flags for errors
  fuse: fsync() did not return IO errors
  fuse: don't mess with blocking signals
  new helper: wait_event_killable_exclusive()
  fuse: improve aio directIO write performance for size extending writes
2016-07-29 12:29:15 -07:00
Miklos Szeredi
4a7f4e88fe fuse: use filemap_check_errors()
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29 14:10:57 +02:00
Maxim Patlasov
9ebce595f6 fuse: fuse_flush must check mapping->flags for errors
fuse_flush() calls write_inode_now() that triggers writeback, but actual
writeback will happen later, on fuse_sync_writes(). If an error happens,
fuse_writepage_end() will set error bit in mapping->flags. So, we have to
check mapping->flags after fuse_sync_writes().

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4d99ff8f12 ("fuse: Turn writeback cache on")
Cc: <stable@vger.kernel.org> # v3.15+
2016-07-29 14:10:57 +02:00
Alexey Kuznetsov
ac7f052b9e fuse: fsync() did not return IO errors
Due to implementation of fuse writeback filemap_write_and_wait_range() does
not catch errors. We have to do this directly after fuse_sync_writes()

Signed-off-by: Alexey Kuznetsov <kuznet@virtuozzo.com>
Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4d99ff8f12 ("fuse: Turn writeback cache on")
Cc: <stable@vger.kernel.org> # v3.15+
2016-07-29 14:10:57 +02:00
Mel Gorman
11fb998986 mm: move most file-based accounting to the node
There are now a number of accounting oddities such as mapped file pages
being accounted for on the node while the total number of file pages are
accounted on the zone.  This can be coped with to some extent but it's
confusing so this patch moves the relevant file-based accounted.  Due to
throttling logic in the page allocator for reliable OOM detection, it is
still necessary to track dirty and writeback pages on a per-zone basis.

[mgorman@techsingularity.net: fix NR_ZONE_WRITE_PENDING accounting]
  Link: http://lkml.kernel.org/r/1468404004-5085-5-git-send-email-mgorman@techsingularity.net
Link: http://lkml.kernel.org/r/1467970510-21195-20-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ashish Sangwan
7879c4e58b fuse: improve aio directIO write performance for size extending writes
While sending the blocking directIO in fuse, the write request is broken
into sub-requests, each of default size 128k and all the requests are sent
in non-blocking background mode if async_dio mode is supported by libfuse.
The process which issue the write wait for the completion of all the
sub-requests. Sending multiple requests parallely gives a chance to perform
parallel writes in the user space fuse implementation if it is
multi-threaded and hence improves the performance.

When there is a size extending aio dio write, we switch to blocking mode so
that we can properly update the size of the file after completion of the
writes. However, in this situation all the sub-requests are sent in
serialized manner where the next request is sent only after receiving the
reply of the current request. Hence the multi-threaded user space
implementation is not utilized properly.

This patch changes the size extending aio dio behavior to exactly follow
blocking dio. For multi threaded fuse implementation having 10 threads and
using buffer size of 64MB to perform async directIO, we are getting double
the speed.

Signed-off-by: Ashish Sangwan <ashishsangwan2@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-06-30 13:14:10 +02:00
Linus Torvalds
c2e7b20705 Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs cleanups from Al Viro:
 "More cleanups from Christoph"

* 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nfsd: use RWF_SYNC
  fs: add RWF_DSYNC aand RWF_SYNC
  ceph: use generic_write_sync
  fs: simplify the generic_write_sync prototype
  fs: add IOCB_SYNC and IOCB_DSYNC
  direct-io: remove the offset argument to dio_complete
  direct-io: eliminate the offset argument to ->direct_IO
  xfs: eliminate the pos variable in xfs_file_dio_aio_write
  filemap: remove the pos argument to generic_file_direct_write
  filemap: remove pos variables in generic_file_read_iter
2016-05-17 15:05:23 -07:00
Christoph Hellwig
c8b8e32d70 direct-io: eliminate the offset argument to ->direct_IO
Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig
1af5bb491f filemap: remove the pos argument to generic_file_direct_write
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Ashish Samant
2c932d4c91 fuse: Fix return value from fuse_get_user_pages()
fuse_get_user_pages() should return error or 0. Otherwise fuse_direct_io
read will not return 0 to indicate that read has completed.

Fixes: 742f992708 ("fuse: return patrial success from fuse_direct_io()")
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-04-25 13:01:04 +02:00
Kirill A. Shutemov
09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Ashish Samant
742f992708 fuse: return patrial success from fuse_direct_io()
If a user calls writev/readv in direct io mode with partially valid data
in the iovec array such that any vector other than the first one in the
array contains invalid data, we currently return the error for the invalid
iovec.

Instead, we should return the number of bytes already written/read and not
the error as we do in the non direct_io case.

Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-03-16 14:38:31 +01:00
Seth Forshee
744742d692 fuse: Add reference counting for fuse_io_priv
The 'reqs' member of fuse_io_priv serves two purposes. First is to track
the number of oustanding async requests to the server and to signal that
the io request is completed. The second is to be a reference count on the
structure to know when it can be freed.

For sync io requests these purposes can be at odds.  fuse_direct_IO() wants
to block until the request is done, and since the signal is sent when
'reqs' reaches 0 it cannot keep a reference to the object. Yet it needs to
use the object after the userspace server has completed processing
requests. This leads to some handshaking and special casing that it
needlessly complicated and responsible for at least one race condition.

It's much cleaner and safer to maintain a separate reference count for the
object lifecycle and to let 'reqs' just be a count of outstanding requests
to the userspace server. Then we can know for sure when it is safe to free
the object without any handshaking or special cases.

The catch here is that most of the time these objects are stack allocated
and should not be freed. Initializing these objects with a single reference
that is never released prevents accidental attempts to free the objects.

Fixes: 9d5722b777 ("fuse: handle synchronous iocbs internally")
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-03-14 15:02:51 +01:00
Robert Doebbelin
7cabc61e01 fuse: do not use iocb after it may have been freed
There's a race in fuse_direct_IO(), whereby is_sync_kiocb() is called on an
iocb that could have been freed if async io has already completed.  The fix
in this case is simple and obvious: cache the result before starting io.

It was discovered by KASan:

kernel: ==================================================================
kernel: BUG: KASan: use after free in fuse_direct_IO+0xb1a/0xcc0 at addr ffff88036c414390

Signed-off-by: Robert Doebbelin <robert@quobyte.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: bcba24ccdc ("fuse: enable asynchronous processing direct IO")
Cc: <stable@vger.kernel.org> # 3.10+
2016-03-14 15:02:50 +01:00
Al Viro
5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Linus Torvalds
5c89e9ea7e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
 "This adds SEEK_HOLE and SEEK_DATA support in lseek"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add support for SEEK_HOLE and SEEK_DATA in lseek
2016-01-21 12:14:24 -08:00
Linus Torvalds
732c4a9e14 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse fixes from Miklos Szeredi:
 "Two bugfixes, both bound for -stable"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: break infinite loop in fuse_fill_write_pages()
  cuse: fix memory leak
2015-12-11 10:56:41 -08:00
Ravishankar N
0b5da8db14 fuse: add support for SEEK_HOLE and SEEK_DATA in lseek
A useful performance improvement for accessing virtual machine images
via FUSE mount.

See https://bugzilla.redhat.com/show_bug.cgi?id=1220173 for a use-case
for glusterFS.

Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2015-11-10 10:32:37 +01:00
Roman Gushchin
3ca8138f01 fuse: break infinite loop in fuse_fill_write_pages()
I got a report about unkillable task eating CPU. Further
investigation shows, that the problem is in the fuse_fill_write_pages()
function. If iov's first segment has zero length, we get an infinite
loop, because we never reach iov_iter_advance() call.

Fix this by calling iov_iter_advance() before repeating an attempt to
copy data from userspace.

A similar problem is described in 124d3b7041 ("fix writev regression:
pan hanging unkillable and un-straceable"). If zero-length segmend
is followed by segment with invalid address,
iov_iter_fault_in_readable() checks only first segment (zero-length),
iov_iter_copy_from_user_atomic() skips it, fails at second and
returns zero -> goto again without skipping zero-length segment.

Patch calls iov_iter_advance() before goto again: we'll skip zero-length
segment at second iteraction and iov_iter_fault_in_readable() will detect
invalid address.

Special thanks to Konstantin Khlebnikov, who helped a lot with the commit
description.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Maxim Patlasov <mpatlasov@parallels.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Roman Gushchin <klamm@yandex-team.ru>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Fixes: ea9b9907b8 ("fuse: implement perform_write")
Cc: <stable@vger.kernel.org>
2015-11-10 10:32:37 +01:00
Benjamin Coddington
4f6563677a Move locks API users to locks_lock_inode_wait()
Instead of having users check for FL_POSIX or FL_FLOCK to call the correct
locks API function, use the check within locks_lock_inode_wait().  This
allows for some later cleanup.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
2015-10-22 14:57:36 -04:00