Commit Graph

137 Commits

Author SHA1 Message Date
Miklos Szeredi 9759bd5189 fuse: add memory barrier to INIT
Theoretically we need to order setting of various fields in fc with
fc->initialized.

No known bug reports related to this yet.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-01-06 10:45:35 +01:00
Miklos Szeredi 21f621741a fuse: fix LOOKUP vs INIT compat handling
Analysis from Marc:

 "Commit 7078187a79 ("fuse: introduce fuse_simple_request() helper")
  from the above pull request triggers some EIO errors for me in some tests
  that rely on fuse

  Looking at the code changes and a bit of debugging info I think there's a
  general problem here that fuse_get_req checks and possibly waits for
  fc->initialized, and this was always called first.  But this commit
  changes the ordering and in many places fc->minor is now possibly used
  before fuse_get_req, and we can't be sure that fc has been initialized.
  In my case fuse_lookup_init sets req->out.args[0].size to the wrong size
  because fc->minor at that point is still 0, leading to the EIO error."

Fix by moving the compat adjustments into fuse_simple_request() to after
fuse_get_req().

This is also more readable than the original, since now compatibility is
handled in a single function instead of cluttering each operation.

Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Fixes: 7078187a79 ("fuse: introduce fuse_simple_request() helper")
2015-01-06 10:45:35 +01:00
Miklos Szeredi 7078187a79 fuse: introduce fuse_simple_request() helper
The following pattern is repeated many times:

	req = fuse_get_req_nopages(fc);
	/* Initialize req->(in|out).args */
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(req);

Create a new replacement helper:

	/* Initialize args */
	err = fuse_simple_request(fc, &args);

In addition to reducing the code size, this will ease moving from the
complex arg-based to a simpler page-based I/O on the fuse device.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-12 09:49:05 +01:00
Linus Torvalds 0b632204c7 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse fixes from Miklos Szeredi:
 "This contains miscellaneous fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: replace count*size kzalloc by kcalloc
  fuse: release temporary page if fuse_writepage_locked() failed
  fuse: restructure ->rename2()
  fuse: avoid scheduling while atomic
  fuse: handle large user and group ID
  fuse: inode: drop cast
  fuse: ignore entry-timeout on LOOKUP_REVAL
  fuse: timeout comparison fix
2014-07-15 08:57:17 -07:00
Miklos Szeredi c55a01d360 fuse: avoid scheduling while atomic
As reported by Richard Sharpe, an attempt to use fuse_notify_inval_entry()
triggers complains about scheduling while atomic:

  BUG: scheduling while atomic: fuse.hf/13976/0x10000001

This happens because fuse_notify_inval_entry() attempts to allocate memory
with GFP_KERNEL, holding "struct fuse_copy_state" mapped by kmap_atomic().

Introduced by commit 58bda1da4b "fuse/dev: use atomic maps"

Fix by moving the map/unmap to just cover the actual memcpy operation.

Original patch from Maxim Patlasov <mpatlasov@parallels.com>

Reported-by: Richard Sharpe <realrichardsharpe@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: <stable@vger.kernel.org> # v3.15+
2014-07-07 15:28:51 +02:00
Mel Gorman b745bc85f2 mm: page_alloc: convert hot/cold parameter and immediate callers to bool
cold is a bool, make it one.  Make the likely case the "if" part of the
block instead of the else as according to the optimisation manual this is
preferred.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:09 -07:00
Al Viro fbb32750a6 pipe: kill ->map() and ->unmap()
all pipe_buffer_operations have the same instances of those...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:19 -04:00
Al Viro 58bda1da4b fuse/dev: use atomic maps
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:18 -04:00
Miklos Szeredi 063ec1e595 fuse: fix SetPageUptodate() condition in STORE
As noticed by Coverity the "num != 0" condition never triggers.  Instead it
should check for a complete page.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-01-22 19:36:58 +01:00
Miklos Szeredi 28a625cbc2 fuse: fix pipe_buf_operations
Having this struct in module memory could Oops when if the module is
unloaded while the buffer still persists in a pipe.

Since sock_pipe_buf_ops is essentially the same as fuse_dev_pipe_buf_steal
merge them into nosteal_pipe_buf_ops (this is the same as
default_pipe_buf_ops except stealing the page from the buffer is not
allowed).

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
2014-01-22 19:36:57 +01:00
Dong Fang 05726acabe fuse: use list_for_each_entry() for list traversing
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-09-04 17:42:42 +02:00
Linus Torvalds 5af43c24ca Merge branch 'akpm' (incoming from Andrew)
Merge more incoming from Andrew Morton:

 - Various fixes which were stalled or which I picked up recently

 - A large rotorooting of the AIO code.  Allegedly to improve
   performance but I don't really have good performance numbers (I might
   have lost the email) and I can't raise Kent today.  I held this out
   of 3.9 and we could give it another cycle if it's all too late/scary.

I ended up taking only the first two thirds of the AIO rotorooting.  I
left the percpu parts and the batch completion for later.  - Linus

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (33 commits)
  aio: don't include aio.h in sched.h
  aio: kill ki_retry
  aio: kill ki_key
  aio: give shared kioctx fields their own cachelines
  aio: kill struct aio_ring_info
  aio: kill batch allocation
  aio: change reqs_active to include unreaped completions
  aio: use cancellation list lazily
  aio: use flush_dcache_page()
  aio: make aio_read_evt() more efficient, convert to hrtimers
  wait: add wait_event_hrtimeout()
  aio: refcounting cleanup
  aio: make aio_put_req() lockless
  aio: do fget() after aio_get_req()
  aio: dprintk() -> pr_debug()
  aio: move private stuff out of aio.h
  aio: add kiocb_cancel()
  aio: kill return value of aio_complete()
  char: add aio_{read,write} to /dev/{null,zero}
  aio: remove retry-based AIO
  ...
2013-05-07 20:49:51 -07:00
Kent Overstreet a27bb332c0 aio: don't include aio.h in sched.h
Faster kernel compiles by way of fewer unnecessary includes.

[akpm@linux-foundation.org: fix fallout]
[akpm@linux-foundation.org: fix build]
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-07 20:16:25 -07:00
Linus Torvalds a26ea93a3d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
 "This contains two patchsets from Maxim Patlasov.

  The first reworks the request throttling so that only async requests
  are throttled.  Wakeup of waiting async requests is also optimized.

  The second series adds support for async processing of direct IO which
  optimizes direct IO and enables the use of the AIO userspace
  interface."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add flag to turn on async direct IO
  fuse: truncate file if async dio failed
  fuse: optimize short direct reads
  fuse: enable asynchronous processing direct IO
  fuse: make fuse_direct_io() aware about AIO
  fuse: add support of async IO
  fuse: move fuse_release_user_pages() up
  fuse: optimize wake_up
  fuse: implement exclusive wakeup for blocked_waitq
  fuse: skip blocking on allocations of synchronous requests
  fuse: add flag fc->initialized
  fuse: make request allocations for background processing explicit
2013-05-07 10:12:32 -07:00
Maxim Patlasov 36cf66ed9f fuse: make fuse_direct_io() aware about AIO
The patch implements passing "struct fuse_io_priv *io" down the stack up to
fuse_send_read/write where it is used to submit request asynchronously.
io->async==0 designates synchronous processing.

Non-trivial part of the patch is changes in fuse_direct_io(): resources
like fuse requests and user pages cannot be released immediately in async
case.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 21:50:59 +02:00
Miklos Szeredi 3c18ef8117 fuse: optimize wake_up
Normally blocked_waitq will be inactive, so optimize this case.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 21:50:58 +02:00
Maxim Patlasov 722d2bea8c fuse: implement exclusive wakeup for blocked_waitq
The patch solves thundering herd problem. So far as previous patches ensured
that only allocations for background may block, it's safe to wake up one
waiter. Whoever it is, it will wake up another one in request_end() afterwards.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 12:31:45 +02:00
Maxim Patlasov 0aada88476 fuse: skip blocking on allocations of synchronous requests
A task may have at most one synchronous request allocated. So these
requests need not be otherwise limited.

The patch re-works fuse_get_req() to follow this idea.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 12:31:45 +02:00
Maxim Patlasov 796523fb24 fuse: add flag fc->initialized
Existing flag fc->blocked is used to suspend request allocation both in case
of many background request submitted and period of time before init_reply
arrives from userspace. Next patch will skip blocking allocations of
synchronous request (disregarding fc->blocked). This is mostly OK, but
we still need to suspend allocations if init_reply is not arrived yet. The
patch introduces flag fc->initialized which will serve this purpose.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 12:31:44 +02:00
Maxim Patlasov 8b41e6715e fuse: make request allocations for background processing explicit
There are two types of processing requests in FUSE: synchronous (via
fuse_request_send()) and asynchronous (via adding to fc->bg_queue).

Fortunately, the type of processing is always known in advance, at the time
of request allocation. This preparatory patch utilizes this fact making
fuse_get_req() aware about the type. Next patches will use it.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 12:31:44 +02:00
Al Viro 6447a3cf19 get rid of pipe->inode
it's used only as a flag to distinguish normal pipes/FIFOs from the
internal per-task one used by file-to-file splice.  And pipe->files
would work just as well for that purpose...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:01 -04:00
Al Viro 6131ffaa1f more file_inode() open-coded instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-27 16:59:05 -05:00
Eric Wong 6a4e922c3d fuse: avoid out-of-scope stack access
The all pointers within fuse_req must point to valid memory once
fuse_force_forget() returns.

This bug appeared in "fuse: implement NFS-like readdirplus support"
and was never in any official Linux release.

I tested the fuse_force_forget() code path by injecting to fake -ENOMEM and
verified the FORGET operation was called properly in userspace.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-02-04 15:22:23 +01:00
Maxim Patlasov 85f40aec88 fuse: use req->page_descs[] for argpages cases
Previously, anyone who set flag 'argpages' only filled req->pages[] and set
per-request page_offset. This patch re-works all cases where argpages=1 to
fill req->page_descs[] properly.

Having req->page_descs[] filled properly allows to re-work fuse_copy_pages()
to copy page fragments described by req->page_descs[]. This will be useful
for next patches optimizing direct_IO.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:27 +01:00
Maxim Patlasov b2430d7567 fuse: add per-page descriptor <offset, length> to fuse_req
The ability to save page pointers along with lengths and offsets in fuse_req
will be useful to cover several iovec-s with a single fuse_req.

Per-request page_offset is removed because anybody who need it can use
req->page_descs[0].offset instead.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:27 +01:00
Maxim Patlasov 4d53dc99ba fuse: rework fuse_retrieve()
The patch reworks fuse_retrieve() to allocate only so many page pointers
as needed. The core part of the patch is the following calculation:

	num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;

(thanks Miklos for formula). All other changes are mostly shuffling lines.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:26 +01:00
Maxim Patlasov b111c8c0e3 fuse: categorize fuse_get_req()
The patch categorizes all fuse_get_req() invocations into two categories:
 - fuse_get_req_nopages(fc) - when caller doesn't care about req->pages
 - fuse_get_req(fc, n) - when caller need n page pointers (n > 0)

Adding fuse_get_req_nopages() helps to avoid numerous fuse_get_req(fc, 0)
scattered over code. Now it's clear from the first glance when a caller need
fuse_req with page pointers.

The patch doesn't make any logic changes. In multi-page case, it silly
allocates array of FUSE_MAX_PAGES_PER_REQ page pointers. This will be amended
by future patches.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:25 +01:00
Maxim Patlasov 4250c0668e fuse: general infrastructure for pages[] of variable size
The patch removes inline array of FUSE_MAX_PAGES_PER_REQ page pointers from
fuse_req. Instead of that, req->pages may now point either to small inline
array or to an array allocated dynamically.

This essentially means that all callers of fuse_request_alloc[_nofs] should
pass the number of pages needed explicitly.

The patch doesn't make any logic changes.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:25 +01:00
Anand V. Avati 0b05b18381 fuse: implement NFS-like readdirplus support
This patch implements readdirplus support in FUSE, similar to NFS.
The payload returned in the readdirplus call contains
'fuse_entry_out' structure thereby providing all the necessary inputs
for 'faking' a lookup() operation on the spot.

If the dentry and inode already existed (for e.g. in a re-run of ls -l)
then just the inode attributes timeout and dentry timeout are refreshed.

With a simple client->network->server implementation of a FUSE based
filesystem, the following performance observations were made:

Test: Performing a filesystem crawl over 20,000 files with

sh# time ls -lR /mnt

Without readdirplus:
Run 1: 18.1s
Run 2: 16.0s
Run 3: 16.2s

With readdirplus:
Run 1: 4.1s
Run 2: 3.8s
Run 3: 3.8s

The performance improvement is significant as it avoided 20,000 upcalls
calls (lookup). Cache consistency is no worse than what already is.

Signed-off-by: Anand V. Avati <avati@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:25 +01:00
Wei Yongjun 8f706111a8 fuse: remove unused variable in fuse_try_move_page()
The variables mapping,index are initialized but never used
otherwise, so remove the unused variables.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-17 13:09:59 +01:00
Eric W. Biederman 499dcf2024 userns: Support fuse interacting with multiple user namespaces
Use kuid_t and kgid_t in struct fuse_conn and struct fuse_mount_data.

The connection between between a fuse filesystem and a fuse daemon is
established when a fuse filesystem is mounted and provided with a file
descriptor the fuse daemon created by opening /dev/fuse.

For now restrict the communication of uids and gids between the fuse
filesystem and the fuse daemon to the initial user namespace.  Enforce
this by verifying the file descriptor passed to the mount of fuse was
opened in the initial user namespace.  Ensuring the mount happens in
the initial user namespace is not necessary as mounts from non-initial
user namespaces are not yet allowed.

In fuse_req_init_context convert the currrent fsuid and fsgid into the
initial user namespace for the request that will be sent to the fuse
daemon.

In fuse_fill_attr convert the uid and gid passed from the fuse daemon
from the initial user namespace into kuids and kgids.

In iattr_to_fattr called from fuse_setattr convert kuids and kgids
into the uids and gids in the initial user namespace before passing
them to the fuse filesystem.

In fuse_change_attributes_common called from fuse_dentry_revalidate,
fuse_permission, fuse_geattr, and fuse_setattr, and fuse_iget convert
the uid and gid from the fuse daemon into a kuid and a kgid to store
on the fuse inode.

By default fuse mounts are restricted to task whose uid, suid, and
euid matches the fuse user_id and whose gid, sgid, and egid matches
the fuse group id.  Convert the user_id and group_id mount options
into kuids and kgids at mount time, and use uid_eq and gid_eq to
compare the in fuse_allow_task.

Cc: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-11-14 22:05:33 -08:00
Al Viro cb0942b812 make get_file() return its argument
simplifies a bunch of callers...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:25 -04:00
Miklos Szeredi c9e67d4837 fuse: fix retrieve length
In some cases fuse_retrieve() would return a short byte count if offset was
non-zero.  The data returned was correct, though.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
2012-09-04 18:45:54 +02:00
Cong Wang 2408f6ef6b fuse: remove the second argument of k[un]map_atomic()
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:22 +08:00
John Muir 451d0f5999 FUSE: Notifying the kernel of deletion.
Allows a FUSE file-system to tell the kernel when a file or directory is
deleted. If the specified dentry has the specified inode number, the kernel will
unhash it.

The current 'fuse_notify_inval_entry' does not cause the kernel to clean up
directories that are in use properly, and as a result the users of those
directories see incorrect semantics from the file-system. The error condition
seen when 'fuse_notify_inval_entry' is used to notify of a deleted directory is
avoided when 'fuse_notify_delete' is used instead.

The following scenario demonstrates the difference:
1. User A chdirs into 'testdir' and starts reading 'testfile'.
2. User B rm -rf 'testdir'.
3. User B creates 'testdir'.
4. User C chdirs into 'testdir'.

If you run the above within the same machine on any file-system (including fuse
file-systems), there is no problem: user C is able to chdir into the new
testdir. The old testdir is removed from the dentry tree, but still open by user
A.

If operations 2 and 3 are performed via the network such that the fuse
file-system uses one of the notify functions to tell the kernel that the nodes
are gone, then the following error occurs for user C while user A holds the
original directory open:

muirj@empacher:~> ls /test/testdir
ls: cannot access /test/testdir: No such file or directory

The issue here is that the kernel still has a dentry for testdir, and so it is
requesting the attributes for the old directory, while the file-system is
responding that the directory no longer exists.

If on the other hand, if the file-system can notify the kernel that the
directory is deleted using the new 'fuse_notify_delete' function, then the above
ls will find the new directory as expected.

Signed-off-by: John Muir <john@jmuir.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-12-13 11:58:49 +01:00
Miklos Szeredi 48706d0a91 fuse: fix fuse_retrieve
Fix two bugs in fuse_retrieve():

 - retrieving more than one page would yield repeated instances of the
   first page

 - if more than FUSE_MAX_PAGES_PER_REQ pages were requested than the
   request page array would overflow

fuse_retrieve() was added in 2.6.36 and these bugs had been there since the
beginning.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
2011-12-13 10:36:59 +01:00
Miklos Szeredi 5dfcc87fd7 fuse: fix memory leak
kmemleak is reporting that 32 bytes are being leaked by FUSE:

  unreferenced object 0xe373b270 (size 32):
  comm "fusermount", pid 1207, jiffies 4294707026 (age 2675.187s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<b05517d7>] kmemleak_alloc+0x27/0x50
    [<b0196435>] kmem_cache_alloc+0xc5/0x180
    [<b02455be>] fuse_alloc_forget+0x1e/0x20
    [<b0245670>] fuse_alloc_inode+0xb0/0xd0
    [<b01b1a8c>] alloc_inode+0x1c/0x80
    [<b01b290f>] iget5_locked+0x8f/0x1a0
    [<b0246022>] fuse_iget+0x72/0x1a0
    [<b02461da>] fuse_get_root_inode+0x8a/0x90
    [<b02465cf>] fuse_fill_super+0x3ef/0x590
    [<b019e56f>] mount_nodev+0x3f/0x90
    [<b0244e95>] fuse_mount+0x15/0x20
    [<b019d1bc>] mount_fs+0x1c/0xc0
    [<b01b5811>] vfs_kern_mount+0x41/0x90
    [<b01b5af9>] do_kern_mount+0x39/0xd0
    [<b01b7585>] do_mount+0x2e5/0x660
    [<b01b7966>] sys_mount+0x66/0xa0

This leak report is consistent and happens once per boot on
3.1.0-rc5-dirty.

This happens if a FORGET request is queued after the fuse device was
released.

Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-12 11:47:10 -07:00
Miklos Szeredi c2183d1e9b fuse: check size of FUSE_NOTIFY_INVAL_ENTRY message
FUSE_NOTIFY_INVAL_ENTRY didn't check the length of the write so the
message processing could overrun and result in a "kernel BUG at
fs/fuse/dev.c:629!"

Reported-by: Han-Wen Nienhuys <hanwenn@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
2011-08-24 10:20:17 +02:00
Miklos Szeredi ef6a3c6311 mm: add replace_page_cache_page() function
This function basically does:

     remove_from_page_cache(old);
     page_cache_release(old);
     add_to_page_cache_locked(new);

Except it does this atomically, so there's no possibility for the "add" to
fail because of a race.

If memory cgroups are enabled, then the memory cgroup charge is also moved
from the old page to the new.

This function is currently used by fuse to move pages into the page cache
on read, instead of copying the page contents.

[minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22 17:44:02 -07:00
Bryan Green 357ccf2b69 fuse: wakeup pollers on connection release/abort
If a fuse dev connection is broken, wake up any
processes that are blocking, in a poll system call,
on one of the files in the now defunct filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-03-21 13:58:05 +01:00
Miklos Szeredi 02c048b919 fuse: allow batching of FORGET requests
Terje Malmedal reports that a fuse filesystem with 32 million inodes
on a machine with lots of memory can take up to 30 minutes to process
FORGET requests when all those inodes are evicted from the icache.

To solve this, create a BATCH_FORGET request that allows up to about
8000 FORGET requests to be sent in a single message.

This request is only sent if userspace supports interface version 7.16
or later, otherwise fall back to sending individual FORGET messages.

Reported-by: Terje Malmedal <terje.malmedal@usit.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-12-07 20:16:56 +01:00
Miklos Szeredi 07e77dca8a fuse: separate queue for FORGET requests
Terje Malmedal reports that a fuse filesystem with 32 million inodes
on a machine with lots of memory can go unresponsive for up to 30
minutes when all those inodes are evicted from the icache.

The reason is that FORGET messages, sent when the inode is evicted,
are queued up together with regular filesystem requests, and while the
huge queue of FORGET messages are processed no other filesystem
operation can proceed.

Since a full fuse request structure is allocated for each inode, these
take up quite a bit of memory as well.

To solve these issues, create a slim 'fuse_forget_link' structure
containing just the minimum of information required to send the FORGET
request and chain these on a separate queue.

When userspace is asking for a request make sure that FORGET and
non-FORGET requests are selected fairly: for each 8 non-FORGET allow
16 FORGET requests.  This will make sure FORGETs do not pile up, yet
other requests are also allowed to proceed while the queued FORGETs
are processed.

Reported-by: Terje Malmedal <terje.malmedal@usit.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-12-07 20:16:56 +01:00
Miklos Szeredi 0be8557bcd fuse: use release_pages()
Replace iterated page_cache_release() with release_pages(), which is
faster and shorter.

Needs release_pages() to be exported to modules.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:17 -07:00
Miklos Szeredi b6777c40c7 fuse: use clear_highpage() and KM_USER0 instead of KM_USER1
Commit 7909b1c640 ("fuse: don't use atomic kmap") removed KM_USER0 usage
from fuse/dev.c.  Switch KM_USER1 uses to KM_USER0 for clarity.  Also
replace open coded clear_highpage().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:13 -07:00
Jan Beulich 3ecb01df32 use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages
After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:13 -07:00
Geert Uytterhoeven 0157443c56 fuse: Initialize total_len in fuse_retrieve()
fs/fuse/dev.c:1357: warning: ‘total_len’ may be used uninitialized in this
function

Initialize total_len to zero, else its value will be undefined.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-10-04 10:45:32 +02:00
Miklos Szeredi b9ca67b2dd fuse: fix lock annotations
Sparse doesn't understand lock annotations of the form
__releases(&foo->lock).  Change them to __releases(foo->lock).  Same
for __acquires().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-09-07 13:42:41 +02:00
Miklos Szeredi 595afaf9e6 fuse: flush background queue on connection close
David Bartly reported that fuse can hang in fuse_get_req_nofail() when
the connection to the filesystem server is no longer active.

If bg_queue is not empty then flush_bg_queue() called from
request_end() can put more requests on to the pending queue.  If this
happens while ending requests on the processing queue then those
background requests will be queued to the pending list and never
ended.

Another problem is that fuse_dev_release() didn't wake up processes
sleeping on blocked_waitq.

Solve this by:

 a) flushing the background queue before calling end_requests() on the
    pending and processing queues

 b) setting blocked = 0 and waking up processes waiting on
    blocked_waitq()

Thanks to David for an excellent bug report.

Reported-by: David Bartley <andareed@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
2010-09-07 13:42:41 +02:00
Miklos Szeredi 2d45ba381a fuse: add retrieve request
Userspace filesystem can request data to be retrieved from the inode's
mapping.  This request is synchronous and the retrieved data is queued
as a new request.  If the write to the fuse device returns an error
then the retrieve request was not completed and a reply will not be
sent.

Only present pages are returned in the retrieve reply.  Retrieving
stops when it finds a non-present page and only data prior to that is
returned.

This request doesn't change the dirty state of pages.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-07-12 14:41:40 +02:00
Miklos Szeredi a1d75f2582 fuse: add store request
Userspace filesystem can request data to be stored in the inode's
mapping.  This request is synchronous and has no reply.  If the write
to the fuse device returns an error then the store request was not
fully completed (but may have updated some pages).

If the stored data overflows the current file size, then the size is
extended, similarly to a write(2) on the filesystem.

Pages which have been completely stored are marked uptodate.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-07-12 14:41:40 +02:00