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266 commits

Author SHA1 Message Date
Rajat Jain f3846266f5 fuse: fix "uninitialized variable" warning
Fix the following warning:

In file included from include/linux/fs.h:16:0,
                 from fs/fuse/fuse_i.h:13,
                 from fs/fuse/file.c:9:
fs/fuse/file.c: In function 'fuse_file_poll':
include/linux/rbtree.h:82:28: warning: 'parent' may be used
uninitialized in this function [-Wmaybe-uninitialized]
fs/fuse/file.c:2592:27: note: 'parent' was declared here

Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:51 +02:00
Pavel Emelyanov 4d99ff8f12 fuse: Turn writeback cache on
Introduce a bit kernel and userspace exchange between each-other on
the init stage and turn writeback on if the userspace want this and
mount option 'allow_wbcache' is present (controlled by fusermount).

Also add each writable file into per-inode write list and call the
generic_file_aio_write to make use of the Linux page cache engine.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:50 +02:00
Pavel Emelyanov ea8cd33390 fuse: Fix O_DIRECT operations vs cached writeback misorder
The problem is:

1. write cached data to a file
2. read directly from the same file (via another fd)

The 2nd operation may read stale data, i.e. the one that was in a file
before the 1st op. Problem is in how fuse manages writeback.

When direct op occurs the core kernel code calls filemap_write_and_wait
to flush all the cached ops in flight. But fuse acks the writeback right
after the ->writepages callback exits w/o waiting for the real write to
happen. Thus the subsequent direct op proceeds while the real writeback
is still in flight. This is a problem for backends that reorder operation.

Fix this by making the fuse direct IO callback explicitly wait on the
in-flight writeback to finish.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:50 +02:00
Maxim Patlasov fe38d7df23 fuse: fuse_flush() should wait on writeback
The aim of .flush fop is to hint file-system that flushing its state or caches
or any other important data to reliable storage would be desirable now.
fuse_flush() passes this hint by sending FUSE_FLUSH request to userspace.
However, dirty pages and pages under writeback may be not visible to userspace
yet if we won't ensure it explicitly.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:50 +02:00
Pavel Emelyanov 6b12c1b37e fuse: Implement write_begin/write_end callbacks
The .write_begin and .write_end are requiered to use generic routines
(generic_file_aio_write --> ... --> generic_perform_write) for buffered
writes.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:49 +02:00
Maxim Patlasov 482fce55d2 fuse: restructure fuse_readpage()
Move the code filling and sending read request to a separate function. Future
patches will use it for .write_begin -- partial modification of a page
requires reading the page from the storage very similarly to what fuse_readpage
does.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:49 +02:00
Pavel Emelyanov e7cc133c37 fuse: Flush files on wb close
Any write request requires a file handle to report to the userspace. Thus
when we close a file (and free the fuse_file with this info) we have to
flush all the outstanding dirty pages.

filemap_write_and_wait() is enough because every page under fuse writeback
is accounted in ff->count. This delays actual close until all fuse wb is
completed.

In case of "write cache" turned off, the flush is ensured by fuse_vma_close().

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:49 +02:00
Maxim Patlasov b0aa760652 fuse: Trust kernel i_mtime only
Let the kernel maintain i_mtime locally:
 - clear S_NOCMTIME
 - implement i_op->update_time()
 - flush mtime on fsync and last close
 - update i_mtime explicitly on truncate and fallocate

Fuse inode flag FUSE_I_MTIME_DIRTY serves as indication that local i_mtime
should be flushed to the server eventually.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:48 +02:00
Pavel Emelyanov 8373200b12 fuse: Trust kernel i_size only
Make fuse think that when writeback is on the inode's i_size is always
up-to-date and not update it with the value received from the userspace.
This is done because the page cache code may update i_size without letting
the FS know.

This assumption implies fixing the previously introduced short-read helper --
when a short read occurs the 'hole' is filled with zeroes.

fuse_file_fallocate() is also fixed because now we should keep i_size up to
date, so it must be updated if FUSE_FALLOCATE request succeeded.

Signed-off-by: Maxim V. Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:48 +02:00
Pavel Emelyanov a92adc824e fuse: Prepare to handle short reads
A helper which gets called when read reports less bytes than was requested.
See patch "trust kernel i_size only" for details.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:47 +02:00
Pavel Emelyanov 650b22b941 fuse: Linking file to inode helper
When writeback is ON every writeable file should be in per-inode write list,
not only mmap-ed ones. Thus introduce a helper for this linkage.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-04-02 15:38:47 +02:00
Al Viro 5cb6c6c7eb generic_file_direct_write(): get rid of ppos argument
always equal to &iocb->ki_pos.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:35 -04:00
Al Viro 9e8c2af96e callers of iov_copy_from_user_atomic() don't need pagecache_disable()
... it does that itself (via kmap_atomic())

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:20 -04:00
Linus Torvalds bf3d846b78 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Assorted stuff; the biggest pile here is Christoph's ACL series.  Plus
  assorted cleanups and fixes all over the place...

  There will be another pile later this week"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits)
  __dentry_path() fixes
  vfs: Remove second variable named error in __dentry_path
  vfs: Is mounted should be testing mnt_ns for NULL or error.
  Fix race when checking i_size on direct i/o read
  hfsplus: remove can_set_xattr
  nfsd: use get_acl and ->set_acl
  fs: remove generic_acl
  nfs: use generic posix ACL infrastructure for v3 Posix ACLs
  gfs2: use generic posix ACL infrastructure
  jfs: use generic posix ACL infrastructure
  xfs: use generic posix ACL infrastructure
  reiserfs: use generic posix ACL infrastructure
  ocfs2: use generic posix ACL infrastructure
  jffs2: use generic posix ACL infrastructure
  hfsplus: use generic posix ACL infrastructure
  f2fs: use generic posix ACL infrastructure
  ext2/3/4: use generic posix ACL infrastructure
  btrfs: use generic posix ACL infrastructure
  fs: make posix_acl_create more useful
  fs: make posix_acl_chmod more useful
  ...
2014-01-28 08:38:04 -08:00
Steven Whitehouse 9fe55eea7e Fix race when checking i_size on direct i/o read
So far I've had one ACK for this, and no other comments. So I think it
is probably time to send this via some suitable tree. I'm guessing that
the vfs tree would be the most appropriate route, but not sure that
there is one at the moment (don't see anything recent at kernel.org)
so in that case I think -mm is the "back up plan". Al, please let me
know if you will take this?

Steve.

---------------------

Following on from the "Re: [PATCH v3] vfs: fix a bug when we do some dio
reads with append dio writes" thread on linux-fsdevel, this patch is my
current version of the fix proposed as option (b) in that thread.

Removing the i_size test from the direct i/o read path at vfs level
means that filesystems now have to deal with requests which are beyond
i_size themselves. These I've divided into three sets:

 a) Those with "no op" ->direct_IO (9p, cifs, ceph)
These are obviously not going to be an issue

 b) Those with "home brew" ->direct_IO (nfs, fuse)
I've been told that NFS should not have any problem with the larger
i_size, however I've added an extra test to FUSE to duplicate the
original behaviour just to be on the safe side.

 c) Those using __blockdev_direct_IO()
These call through to ->get_block() which should deal with the EOF
condition correctly. I've verified that with GFS2 and I believe that
Zheng has verified it for ext4. I've also run the test on XFS and it
passes both before and after this change.

The part of the patch in filemap.c looks a lot larger than it really is
- there are only two lines of real change. The rest is just indentation
of the contained code.

There remains a test of i_size though, which was added for btrfs. It
doesn't cause the other filesystems a problem as the test is performed
after ->direct_IO has been called. It is possible that there is a race
that does matter to btrfs, however this patch doesn't change that, so
its still an overall improvement.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-26 08:26:42 -05:00
Andrew Gallagher 7678ac5061 fuse: support clients that don't implement 'open'
open/release operations require userspace transitions to keep track
of the open count and to perform any FS-specific setup.  However,
for some purely read-only FSs which don't need to perform any setup
at open/release time, we can avoid the performance overhead of
calling into userspace for open/release calls.

This patch adds the necessary support to the fuse kernel modules to prevent
open/release operations from hitting in userspace. When the client returns
ENOSYS, we avoid sending the subsequent release to userspace, and also
remember this so that future opens also don't trigger a userspace
operation.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-01-22 19:36:59 +01:00
Andrew Gallagher 451418fc92 fuse: don't invalidate attrs when not using atime
Various read operations (e.g. readlink, readdir) invalidate the cached
attrs for atime changes.  This patch adds a new function
'fuse_invalidate_atime', which checks for a read-only super block and
avoids the attr invalidation in that case.

Signed-off-by: Andrew Gallagher <andrewjcg@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-01-22 19:36:58 +01:00
Maxim Patlasov ce128de626 fuse: writepages: protect secondary requests from fuse file release
All async fuse requests must be supplied with extra reference to a fuse
file.  This is necessary to ensure that the fuse file is not released until
all in-flight requests are completed.  Fuse secondary writeback requests
must obey this rule as well.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-11-05 10:11:29 +01:00
Maxim Patlasov 41b6e41fc6 fuse: writepages: update bdi writeout when deleting secondary request
BDI_WRITTEN counter is used to estimate bdi bandwidth.  It must be
incremented every time as bdi ends page writeback.  No matter whether it
was fulfilled by actual write or by discarding the request (e.g. due to
shrunk i_size).

Note that even before writepages patches, the case "Got truncated off
completely" was handled in fuse_send_writepage() by calling
fuse_writepage_finish() which updated BDI_WRITTEN unconditionally.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-11-05 10:11:28 +01:00
Maxim Patlasov 6eaf4782eb fuse: writepages: crop secondary requests
If writeback happens while fuse is in FUSE_NOWRITE condition, the request
will be queued but not processed immediately (see fuse_flush_writepages()).
Until FUSE_NOWRITE becomes relaxed, more writebacks can happen.  They will
be queued as "secondary" requests to that first ("primary") request.

Existing implementation crops only primary request.  This is not correct
because a subsequent extending write(2) may increase i_size and then
secondary requests won't be cropped properly.  The result would be stale
data written to the server to a file offset where zeros must be.

Similar problem may happen if secondary requests are attached to an
in-flight request that was already cropped.

The patch solves the issue by cropping all secondary requests in
fuse_writepage_end().  Thanks to Miklos for idea.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-11-05 10:11:27 +01:00
Maxim Patlasov f6011081f5 fuse: writepages: roll back changes if request not found
fuse_writepage_in_flight() returns false if it fails to find request with
given index in fi->writepages.  Then the caller proceeds with populating
data->orig_pages[] and incrementing req->num_pages.  Hence,
fuse_writepage_in_flight() must revert changes it made in request before
returning false.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-11-05 10:11:26 +01:00
Miklos Szeredi ff17be0864 fuse: writepage: skip already in flight
If ->writepage() tries to write back a page whose copy is still in flight,
then just skip by calling redirty_page_for_writepage().

This is OK, since now ->writepage() should never be called for data
integrity sync.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:53 +02:00
Miklos Szeredi 8b284dc472 fuse: writepages: handle same page rewrites
As Maxim Patlasov pointed out, it's possible to get a dirty page while it's
copy is still under writeback, despite fuse_page_mkwrite() doing its thing
(direct IO).

This could result in two concurrent write request for the same offset, with
data corruption if they get mixed up.

To prevent this, fuse needs to check and delay such writes.  This
implementation does this by:

 1. check if page is still under writeout, if so create a new, single page
    secondary request for it

 2. chain this secondary request onto the in-flight request

 2/a. if a seconday request for the same offset was already chained to the
    in-flight request, then just copy the contents of the page and discard
    the new secondary request.  This makes sure that for each page will
    have at most two requests associated with it

 3. when the in-flight request finished, send off all secondary requests
    chained onto it

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:53 +02:00
Miklos Szeredi 1e112a484e fuse: writepages: fix aggregation
Checking against tmp-page indexes is not very useful, and results in one
(or rarely two) page requests.  Which is not much of an improvement...

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:53 +02:00
Maxim Patlasov 2d033eaa00 fuse: fix race in fuse_writepages()
The patch fixes a race between ftruncate(2), mmap-ed write and write(2):

1) An user makes a page dirty via mmap-ed write.
2) The user performs shrinking truncate(2) intended to purge the page.
3) Before fuse_do_setattr calls truncate_pagecache, the page goes to
   writeback. fuse_writepages_fill attaches a new page to FUSE_WRITE request,
   then releases the original page by end_page_writeback and unlock it.
4) fuse_do_setattr completes and successfully returns. Since now, i_mutex
   is free.
5) Ordinary write(2) extends i_size back to cover the page. Note that
   fuse_send_write_pages do wait for fuse writeback, but for another
   page->index.
6) fuse_writepages_fill attaches more pages to the request (if any), then
   fuse_writepages_send is eventually called. It is supposed to crop
   inarg->size of the request, but it doesn't because i_size has already been
   extended back.

Moving end_page_writeback behind fuse_writepages_send guarantees that
__fuse_release_nowrite (called from fuse_do_setattr) will crop inarg->size
of the request before write(2) gets the chance to extend i_size.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:53 +02:00
Pavel Emelyanov 26d614df1d fuse: Implement writepages callback
The .writepages one is required to make each writeback request carry more than
one page on it. The patch enables optimized behaviour unconditionally,
i.e. mmap-ed writes will benefit from the patch even if fc->writeback_cache=0.

[SzM: simplify, add comments]

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:52 +02:00
Miklos Szeredi 72523425fb fuse: don't BUG on no write file
Don't bug if there's no writable files found for page writeback.  If ever
this is triggered, a WARN_ON helps debugging it much better then a BUG_ON.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:52 +02:00
Miklos Szeredi cca2437045 fuse: lock page in mkwrite
Lock the page in fuse_page_mkwrite() to protect against a race with
fuse_writepage() where the page is redirtied before the actual writeback
begins.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:51 +02:00
Pavel Emelyanov 385b126815 fuse: Prepare to handle multiple pages in writeback
The .writepages callback will issue writeback requests with more than one
page aboard. Make existing end/check code be aware of this.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:51 +02:00
Pavel Emelyanov adcadfa8f3 fuse: Getting file for writeback helper
There will be a .writepageS callback implementation which will need to
get a fuse_file out of a fuse_inode, thus make a helper for this.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-10-01 16:44:50 +02:00
Maxim Patlasov 0ab08f576b fuse: fix fallocate vs. ftruncate race
A former patch introducing FUSE_I_SIZE_UNSTABLE flag provided detailed
description of races between ftruncate and anyone who can extend i_size:

> 1. As in the previous scenario fuse_dentry_revalidate() discovered that i_size
> changed (due to our own fuse_do_setattr()) and is going to call
> truncate_pagecache() for some  'new_size' it believes valid right now. But by
> the time that particular truncate_pagecache() is called ...
> 2. fuse_do_setattr() returns (either having called truncate_pagecache() or
> not -- it doesn't matter).
> 3. The file is extended either by write(2) or ftruncate(2) or fallocate(2).
> 4. mmap-ed write makes a page in the extended region dirty.

This patch adds necessary bits to fuse_file_fallocate() to protect from that
race.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
2013-09-18 14:19:59 +02:00
Maxim Patlasov bde52788bd fuse: wait for writeback in fuse_file_fallocate()
The patch fixes a race between mmap-ed write and fallocate(PUNCH_HOLE):

1) An user makes a page dirty via mmap-ed write.
2) The user performs fallocate(2) with mode == PUNCH_HOLE|KEEP_SIZE
   and <offset, size> covering the page.
3) Before truncate_pagecache_range call from fuse_file_fallocate,
   the page goes to write-back. The page is fully processed by fuse_writepage
   (including end_page_writeback on the page), but fuse_flush_writepages did
   nothing because fi->writectr < 0.
4) truncate_pagecache_range is called and fuse_file_fallocate is finishing
   by calling fuse_release_nowrite. The latter triggers processing queued
   write-back request which will write stale data to the hole soon.

Changed in v2 (thanks to Brian for suggestion):
 - Do not truncate page cache until FUSE_FALLOCATE succeeded. Otherwise,
   we can end up in returning -ENOTSUPP while user data is already punched
   from page cache. Use filemap_write_and_wait_range() instead.
Changed in v3 (thanks to Miklos for suggestion):
 - fuse_wait_on_writeback() is prone to livelocks; use fuse_set_nowrite()
   instead. So far as we need a dirty-page barrier only, fuse_sync_writes()
   should be enough.
 - rebased to for-linus branch of fuse.git

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
2013-09-18 14:19:59 +02:00
Maxim Patlasov 06a7c3c278 fuse: hotfix truncate_pagecache() issue
The way how fuse calls truncate_pagecache() from fuse_change_attributes()
is completely wrong. Because, w/o i_mutex held, we never sure whether
'oldsize' and 'attr->size' are valid by the time of execution of
truncate_pagecache(inode, oldsize, attr->size). In fact, as soon as we
released fc->lock in the middle of fuse_change_attributes(), we completely
loose control of actions which may happen with given inode until we reach
truncate_pagecache. The list of potentially dangerous actions includes
mmap-ed reads and writes, ftruncate(2) and write(2) extending file size.

The typical outcome of doing truncate_pagecache() with outdated arguments
is data corruption from user point of view. This is (in some sense)
acceptable in cases when the issue is triggered by a change of the file on
the server (i.e. externally wrt fuse operation), but it is absolutely
intolerable in scenarios when a single fuse client modifies a file without
any external intervention. A real life case I discovered by fsx-linux
looked like this:

1. Shrinking ftruncate(2) comes to fuse_do_setattr(). The latter sends
FUSE_SETATTR to the server synchronously, but before getting fc->lock ...
2. fuse_dentry_revalidate() is asynchronously called. It sends FUSE_LOOKUP
to the server synchronously, then calls fuse_change_attributes(). The
latter updates i_size, releases fc->lock, but before comparing oldsize vs
attr->size..
3. fuse_do_setattr() from the first step proceeds by acquiring fc->lock and
updating attributes and i_size, but now oldsize is equal to
outarg.attr.size because i_size has just been updated (step 2). Hence,
fuse_do_setattr() returns w/o calling truncate_pagecache().
4. As soon as ftruncate(2) completes, the user extends file size by
write(2) making a hole in the middle of file, then reads data from the hole
either by read(2) or mmap-ed read. The user expects to get zero data from
the hole, but gets stale data because truncate_pagecache() is not executed
yet.

The scenario above illustrates one side of the problem: not truncating the
page cache even though we should. Another side corresponds to truncating
page cache too late, when the state of inode changed significantly.
Theoretically, the following is possible:

1. As in the previous scenario fuse_dentry_revalidate() discovered that
i_size changed (due to our own fuse_do_setattr()) and is going to call
truncate_pagecache() for some 'new_size' it believes valid right now. But
by the time that particular truncate_pagecache() is called ...
2. fuse_do_setattr() returns (either having called truncate_pagecache() or
not -- it doesn't matter).
3. The file is extended either by write(2) or ftruncate(2) or fallocate(2).
4. mmap-ed write makes a page in the extended region dirty.

The result will be the lost of data user wrote on the fourth step.

The patch is a hotfix resolving the issue in a simplistic way: let's skip
dangerous i_size update and truncate_pagecache if an operation changing
file size is in progress. This simplistic approach looks correct for the
cases w/o external changes. And to handle them properly, more sophisticated
and intrusive techniques (e.g. NFS-like one) would be required. I'd like to
postpone it until the issue is well discussed on the mailing list(s).

Changed in v2:
 - improved patch description to cover both sides of the issue.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
2013-09-03 13:41:58 +02:00
Maxim Patlasov 4a4ac4eba1 fuse: postpone end_page_writeback() in fuse_writepage_locked()
The patch fixes a race between ftruncate(2), mmap-ed write and write(2):

1) An user makes a page dirty via mmap-ed write.
2) The user performs shrinking truncate(2) intended to purge the page.
3) Before fuse_do_setattr calls truncate_pagecache, the page goes to
   writeback. fuse_writepage_locked fills FUSE_WRITE request and releases
   the original page by end_page_writeback.
4) fuse_do_setattr() completes and successfully returns. Since now, i_mutex
   is free.
5) Ordinary write(2) extends i_size back to cover the page. Note that
   fuse_send_write_pages do wait for fuse writeback, but for another
   page->index.
6) fuse_writepage_locked proceeds by queueing FUSE_WRITE request.
   fuse_send_writepage is supposed to crop inarg->size of the request,
   but it doesn't because i_size has already been extended back.

Moving end_page_writeback to the end of fuse_writepage_locked fixes the
race because now the fact that truncate_pagecache is successfully returned
infers that fuse_writepage_locked has already called end_page_writeback.
And this, in turn, infers that fuse_flush_writepages has already called
fuse_send_writepage, and the latter used valid (shrunk) i_size. write(2)
could not extend it because of i_mutex held by ftruncate(2).

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org
2013-09-03 13:41:57 +02:00
Linus Torvalds 790eac5640 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second set of VFS changes from Al Viro:
 "Assorted f_pos race fixes, making do_splice_direct() safe to call with
  i_mutex on parent, O_TMPFILE support, Jeff's locks.c series,
  ->d_hash/->d_compare calling conventions changes from Linus, misc
  stuff all over the place."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  Document ->tmpfile()
  ext4: ->tmpfile() support
  vfs: export lseek_execute() to modules
  lseek_execute() doesn't need an inode passed to it
  block_dev: switch to fixed_size_llseek()
  cpqphp_sysfs: switch to fixed_size_llseek()
  tile-srom: switch to fixed_size_llseek()
  proc_powerpc: switch to fixed_size_llseek()
  ubi/cdev: switch to fixed_size_llseek()
  pci/proc: switch to fixed_size_llseek()
  isapnp: switch to fixed_size_llseek()
  lpfc: switch to fixed_size_llseek()
  locks: give the blocked_hash its own spinlock
  locks: add a new "lm_owner_key" lock operation
  locks: turn the blocked_list into a hashtable
  locks: convert fl_link to a hlist_node
  locks: avoid taking global lock if possible when waking up blocked waiters
  locks: protect most of the file_lock handling with i_lock
  locks: encapsulate the fl_link list handling
  locks: make "added" in __posix_lock_file a bool
  ...
2013-07-03 09:10:19 -07:00
Al Viro cb5e05d1a6 fuse: another open-coded file_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:24 +04:00
Maxim Patlasov 14c14414d1 fuse: hold i_mutex in fuse_file_fallocate()
Changing size of a file on server and local update (fuse_write_update_size)
should be always protected by inode->i_mutex. Otherwise a race like this is
possible:

1. Process 'A' calls fallocate(2) to extend file (~FALLOC_FL_KEEP_SIZE).
fuse_file_fallocate() sends FUSE_FALLOCATE request to the server.
2. Process 'B' calls ftruncate(2) shrinking the file. fuse_do_setattr()
sends shrinking FUSE_SETATTR request to the server and updates local i_size
by i_size_write(inode, outarg.attr.size).
3. Process 'A' resumes execution of fuse_file_fallocate() and calls
fuse_write_update_size(inode, offset + length). But 'offset + length' was
obsoleted by ftruncate from previous step.

Changed in v2 (thanks Brian and Anand for suggestions):
 - made relation between mutex_lock() and fuse_set_nowrite(inode) more
   explicit and clear.
 - updated patch description to use ftruncate(2) in example

Signed-off-by: Maxim V. Patlasov <MPatlasov@parallels.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-06-18 01:39:03 +02:00
Maxim Patlasov e5c5f05dca fuse: fix alignment in short read optimization for async_dio
The bug was introduced with async_dio feature: trying to optimize short reads,
we cut number-of-bytes-to-read to i_size boundary. Hence the following example:

	truncate --size=300 /mnt/file
	dd if=/mnt/file of=/dev/null iflag=direct

led to FUSE_READ request of 300 bytes size. This turned out to be problem
for userspace fuse implementations who rely on assumption that kernel fuse
does not change alignment of request from client FS.

The patch turns off the optimization if async_dio is disabled. And, if it's
enabled, the patch fixes adjustment of number-of-bytes-to-read to preserve
alignment.

Note, that we cannot throw out short read optimization entirely because
otherwise a direct read of a huge size issued on a tiny file would generate
a huge amount of fuse requests and most of them would be ACKed by userspace
with zero bytes read.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-06-03 15:15:42 +02:00
Brian Foster c9ecf989cc fuse: return -EIOCBQUEUED from fuse_direct_IO() for all async requests
If request submission fails for an async request (i.e.,
get_user_pages() returns -ERESTARTSYS), we currently skip the
-EIOCBQUEUED return and drop into wait_for_sync_kiocb() forever.

Avoid this by always returning -EIOCBQUEUED for async requests. If
an error occurs, the error is passed into fuse_aio_complete(),
returned via aio_complete() and thus propagated to userspace via
io_getevents().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-06-03 15:15:42 +02:00
Brian Foster bee6c30780 fuse: update inode size and invalidate attributes on fallocate
An fallocate request without FALLOC_FL_KEEP_SIZE set can extend the
size of a file. Update the inode size after a successful fallocate.

Also invalidate the inode attributes after a successful fallocate
to ensure we pick up the latest attribute values (i.e., i_blocks).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-05-20 16:58:58 +02:00
Brian Foster 3634a63278 fuse: truncate pagecache range on hole punch
fuse supports hole punch via the fallocate() FALLOC_FL_PUNCH_HOLE
interface. When a hole punch is passed through, the page cache
is not cleared and thus allows reading stale data from the cache.

This is easily demonstrable (using FOPEN_KEEP_CACHE) by reading a
smallish random data file into cache, punching a hole and creating
a copy of the file. Drop caches or remount and observe that the
original file no longer matches the file copied after the hole
punch. The original file contains a zeroed range and the latter
file contains stale data.

Protect against writepage requests in progress and punch out the
associated page cache range after a successful client fs hole
punch.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-05-20 16:58:57 +02:00
Brian Foster de82b92301 fuse: allocate for_background dio requests based on io->async state
Commit 8b41e671 introduced explicit background checking for fuse_req
structures with BUG_ON() checks for the appropriate type of request in
in the associated send functions. Commit bcba24cc introduced the ability
to send dio requests as background requests but does not update the
request allocation based on the type of I/O request. As a result, a
BUG_ON() triggers in the fuse_request_send_background() background path if
an async I/O is sent.

Allocate a request based on the async state of the fuse_io_priv to avoid
the BUG.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-05-14 18:25:44 +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
Miklos Szeredi 60b9df7a54 fuse: add flag to turn on async direct IO
Without async DIO write requests to a single file were always serialized.
With async DIO that's no longer the case.

So don't turn on async DIO by default for fear of breaking backward
compatibility.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-05-01 14:37:21 +02:00
Maxim Patlasov efb9fa9e91 fuse: truncate file if async dio failed
The patch improves error handling in fuse_direct_IO(): if we successfully
submitted several fuse requests on behalf of synchronous direct write
extending file and some of them failed, let's try to do our best to clean-up.

Changed in v2: reuse fuse_do_setattr(). Thanks to Brian for suggestion.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-18 10:55:24 +02:00
Maxim Patlasov 439ee5f0c5 fuse: optimize short direct reads
If user requested direct read beyond EOF, we can skip sending fuse requests
for positions beyond EOF because userspace would ACK them with zero bytes read
anyway. We can trust to i_size in fuse_direct_IO for such cases because it's
called from fuse_file_aio_read() and the latter updates fuse attributes
including i_size.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 21:50:59 +02:00
Maxim Patlasov bcba24ccdc fuse: enable asynchronous processing direct IO
In case of synchronous DIO request (i.e. read(2) or write(2) for a file
opened with O_DIRECT), the patch submits fuse requests asynchronously, but
waits for their completions before return from fuse_direct_IO().

In case of asynchronous DIO request (i.e. libaio io_submit() or a file opened
with O_DIRECT), the patch submits fuse requests asynchronously and return
-EIOCBQUEUED immediately.

The only special case is async DIO extending file. Here the patch falls back
to old behaviour because we can't return -EIOCBQUEUED and update i_size later,
without i_mutex hold. And we have no method to wait on real async I/O
requests.

The patch also clean __fuse_direct_write() up: it's better to update i_size
in its callers. Thanks Brian for suggestion.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 21:50:59 +02:00
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
Maxim Patlasov 01e9d11a3e fuse: add support of async IO
The patch implements a framework to process an IO request asynchronously. The
idea is to associate several fuse requests with a single kiocb by means of
fuse_io_priv structure. The structure plays the same role for FUSE as 'struct
dio' for direct-io.c.

The framework is supposed to be used like this:
 - someone (who wants to process an IO asynchronously) allocates fuse_io_priv
   and initializes it setting 'async' field to non-zero value.
 - as soon as fuse request is filled, it can be submitted (in non-blocking way)
   by fuse_async_req_send()
 - when all submitted requests are ACKed by userspace, io->reqs drops to zero
   triggering aio_complete()

In case of IO initiated by libaio, aio_complete() will finish processing the
same way as in case of dio_complete() calling aio_complete(). But the
framework may be also used for internal FUSE use when initial IO request
was synchronous (from user perspective), but it's beneficial to process it
asynchronously. Then the caller should wait on kiocb explicitly and
aio_complete() will wake the caller up.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 21:50:59 +02:00
Maxim Patlasov 187c5c3633 fuse: move fuse_release_user_pages() up
fuse_release_user_pages() will be indirectly used by fuse_send_read/write
in future patches.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-04-17 21:50:58 +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 8d71db4f08 lift sb_start_write/sb_end_write out of ->aio_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:12:55 -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
Enke Chen 0415d29102 fuse: send poll events
commit 626cf23660 "poll: add poll_requested_events()..." enabled us to send the
requested events to the filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-02-04 16:14:32 +01:00
Anatol Pomozov c2132c1bc7 Do not use RCU for current process credentials
Commit c69e8d9c0 added rcu lock to fuse/dir.c It was assuming
that 'task' is some other process but in fact this parameter always
equals to 'current'. Inline this parameter to make it more readable
and remove RCU lock as it is not needed when access current process
credentials.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-31 17:08:10 +01:00
Miklos Szeredi fb05f41f5f fuse: cleanup fuse_direct_io()
Fix the following sparse warnings:

fs/fuse/file.c:1216:43: warning: cast removes address space of expression
fs/fuse/file.c:1216:43: warning: incorrect type in initializer (different address spaces)
fs/fuse/file.c:1216:43:    expected void [noderef] <asn:1>*iov_base
fs/fuse/file.c:1216:43:    got void *<noident>
fs/fuse/file.c:1241:43: warning: cast removes address space of expression
fs/fuse/file.c:1241:43: warning: incorrect type in initializer (different address spaces)
fs/fuse/file.c:1241:43:    expected void [noderef] <asn:1>*iov_base
fs/fuse/file.c:1241:43:    got void *<noident>
fs/fuse/file.c:1267:43: warning: cast removes address space of expression
fs/fuse/file.c:1267:43: warning: incorrect type in initializer (different address spaces)
fs/fuse/file.c:1267:43:    expected void [noderef] <asn:1>*iov_base
fs/fuse/file.c:1267:43:    got void *<noident>

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:28 +01:00
Maxim Patlasov 5565a9d884 fuse: optimize __fuse_direct_io()
__fuse_direct_io() allocates fuse-requests by calling fuse_get_req(fc, n). The
patch calculates 'n' based on iov[] array. This is useful because allocating
FUSE_MAX_PAGES_PER_REQ page pointers and descriptors for each fuse request
would be waste of memory in case of iov-s of smaller size.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-24 16:21:28 +01:00
Maxim Patlasov 7c190c8b9c fuse: optimize fuse_get_user_pages()
Let fuse_get_user_pages() pack as many iov-s to a single fuse_req as
possible. This is very beneficial in case of iov[] consisting of many
iov-s of relatively small sizes (e.g. PAGE_SIZE).

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 b98d023a24 fuse: pass iov[] to fuse_get_user_pages()
The patch makes preliminary work for the next patch optimizing scatter-gather
direct IO. The idea is to allow fuse_get_user_pages() to pack as many iov-s
to each fuse request as possible. So, here we only rework all related
call-paths to carry iov[] from fuse_direct_IO() to fuse_get_user_pages().

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 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 54b966702d fuse: rework fuse_do_ioctl()
fuse_do_ioctl() already calculates the number of pages it's going to use. It is
stored in 'num_pages' variable. So the patch simply uses it for allocating
fuse_req.

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 d07f09f509 fuse: rework fuse_perform_write()
The patch allocates as many page pointers in fuse_req as needed to cover
interval [pos .. pos+len-1]. Inline helper fuse_wr_pages() is introduced
to hide this cumbersome arithmetic.

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 f8dbdf8182 fuse: rework fuse_readpages()
The patch uses 'nr_pages' argument of fuse_readpages() as heuristics for the
number of page pointers to allocate.

This can be improved further by taking in consideration fc->max_read and gaps
between page indices, but it's not clear whether it's worthy or not.

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
Miklos Szeredi cdadb11cef fuse: make fuse_file_fallocate() static
Fix the following sparse warning:

fs/fuse/file.c:2249:6: warning: symbol 'fuse_file_fallocate' was not declared. Should it be static?

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-01-17 13:09:47 +01:00
Andrew Morton 965c8e59cf lseek: the "whence" argument is called "whence"
But the kernel decided to call it "origin" instead.  Fix most of the
sites.

Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:12 -08:00
Konstantin Khlebnikov 0b173bc4da mm: kill vma flag VM_CAN_NONLINEAR
Move actual pte filling for non-linear file mappings into the new special
vma operation: ->remap_pages().

Filesystems must implement this method to get non-linear mapping support,
if it uses filemap_fault() then generic_file_remap_pages() can be used.

Now device drivers can implement this method and obtain nonlinear vma support.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>	#arch/tile
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:17 +09:00
Linus Torvalds 2eac9eb8a2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: verify all ioctl retry iov elements
  fuse: add missing INIT flag descriptions
  fuse: add missing INIT flags
  fuse: update attributes on aio_read
  fuse: invalidate inode mapping if mtime changes
  fuse: add FUSE_AUTO_INVAL_DATA init flag
2012-08-16 11:46:31 -07:00
Zach Brown fb6ccff667 fuse: verify all ioctl retry iov elements
Commit 7572777eef attempted to verify that
the total iovec from the client doesn't overflow iov_length() but it
only checked the first element.  The iovec could still overflow by
starting with a small element.  The obvious fix is to check all the
elements.

The overflow case doesn't look dangerous to the kernel as the copy is
limited by the length after the overflow.  This fix restores the
intention of returning an error instead of successfully copying less
than the iovec represented.

I found this by code inspection.  I built it but don't have a test case.
I'm cc:ing stable because the initial commit did as well.

Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: <stable@vger.kernel.org>         [2.6.37+]
2012-08-06 18:19:24 +02:00
Jan Kara 58ef6a75c3 fuse: Convert to new freezing mechanism
Convert check in fuse_file_aio_write() to using new freeze protection.

CC: fuse-devel@lists.sourceforge.net
CC: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 09:45:50 +04:00
Brian Foster a8894274a3 fuse: update attributes on aio_read
A fuse-based network filesystem might allow for the inode
and/or file data to change unexpectedly. A local client
that opens and repeatedly reads a file might never pick
up on such changes and indefinitely return stale data.

Always invoke fuse_update_attributes() in the read path
to cause an attr revalidation when the attributes expire.
This leads to a page cache invalidation if necessary and
ensures fuse issues new read requests to the fuse client.

The original logic (reval only on reads beyond EOF) is
preserved unless the client specifies FUSE_AUTO_INVAL_DATA
on init.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-07-18 16:09:40 +02:00
Linus Torvalds f9ba7179ce Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix blksize calculation
  fuse: fix stat call on 32 bit platforms
  fuse: optimize fallocate on permanent failure
  fuse: add FALLOCATE operation
  fuse: Convert to kstrtoul_from_user
2012-06-05 10:11:11 -07:00
Josef Bacik c3b2da3148 fs: introduce inode operation ->update_time
Btrfs has to make sure we have space to allocate new blocks in order to modify
the inode, so updating time can fail.  We've gotten around this by having our
own file_update_time but this is kind of a pain, and Christoph has indicated he
would like to make xfs do something different with atime updates.  So introduce
->update_time, where we will deal with i_version an a/m/c time updates and
indicate which changes need to be made.  The normal version just does what it
has always done, updates the time and marks the inode dirty, and then
filesystems can choose to do something different.

I've gone through all of the users of file_update_time and made them check for
errors with the exception of the fault code since it's complicated and I wasn't
quite sure what to do there, also Jan is going to be pushing the file time
updates into page_mkwrite for those who have it so that should satisfy btrfs and
make it not a big deal to check the file_update_time() return code in the
generic fault path. Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-01 12:07:25 -04:00
Miklos Szeredi 519c6040ce fuse: optimize fallocate on permanent failure
If userspace filesystem doesn't support fallocate, remember this and don't send
request next time.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-04-26 10:56:36 +02:00
Anatol Pomozov 05ba1f0823 fuse: add FALLOCATE operation
fallocate filesystem operation preallocates media space for the given file.
If fallocate returns success then any subsequent write to the given range
never fails with 'not enough space' error.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-04-25 12:25:05 +02:00
Linus Torvalds dbfad21422 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: use flexible array in fuse.h
  fuse: allow nanosecond granularity
  fuse: O_DIRECT support for files
  fuse: fix nlink after unlink
2012-04-18 17:29:05 -07:00
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
Anand Avati 4273b793ec fuse: O_DIRECT support for files
Implement ->direct_IO() method in aops. The ->direct_IO() method combines
the existing fuse_direct_read/fuse_direct_write methods to implement
O_DIRECT functionality.

Reaching ->direct_IO() in the read path via generic_file_aio_read ensures
proper synchronization with page cache with its existing framework.

Reaching ->direct_IO() in the write path via fuse_file_aio_write is made
to come via generic_file_direct_write() which makes it play nice with
the page cache w.r.t other mmap pages etc.

On files marked 'direct_io' by the filesystem server, IO always follows
the fuse_direct_read/write path. There is no effect of fcntl(O_DIRECT)
and it always succeeds.

On files not marked with 'direct_io' by the filesystem server, the IO
path depends on O_DIRECT flag by the application. This can be passed
at the time of open() as well as via fcntl().

Note that asynchronous O_DIRECT iocb jobs are completed synchronously
always (this has been the case with FUSE even before this patch)

Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-03-05 15:48:11 +01:00
Miklos Szeredi b18da0c56e fuse: support ioctl on directories
Multiplexing filesystems may want to support ioctls on the underlying
files and directores (e.g. FS_IOC_{GET,SET}FLAGS).

Ioctl support on directories was missing so add it now.

Reported-by: Antonio SJ Musumeci <bile@landofbile.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-12-13 11:58:49 +01:00
Thomas Meyer c411cc88d8 fuse: Use kcalloc instead of kzalloc to allocate array
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-12-13 11:58:49 +01:00
Miklos Szeredi c07c3d1934 fuse: llseek optimize SEEK_CUR and SEEK_SET
Use generic_file_llseek() instead of open coding the seek function.

i_mutex protection is only necessary for SEEK_END (and SEEK_HOLE, SEEK_DATA), so
move SEEK_CUR and SEEK_SET out from under i_mutex.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-12-13 11:58:48 +01:00
Miklos Szeredi 73104b6e37 fuse: llseek fix race
Fix race between lseek(fd, 0, SEEK_CUR) and read/write.  This was fixed in
generic code by commit 5b6f1eb97d (vfs: lseek(fd, 0, SEEK_CUR) race condition).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-12-13 11:40:59 +01:00
Roel Kluin b48c6af208 fuse: fix llseek bug
The test in fuse_file_llseek() "not SEEK_CUR or not SEEK_SET" always evaluates
to true.

This was introduced in 3.1 by commit 06222e49 (fs: handle SEEK_HOLE/SEEK_DATA
properly in all fs's that define their own llseek) and changed the behavior of
SEEK_CUR and SEEK_SET to always retrieve the file attributes.  This is a
performance regression.

Fix the test so that it makes sense.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
CC: Josef Bacik <josef@redhat.com>
CC: Al Viro <viro@zeniv.linux.org.uk>
2011-12-13 10:37:00 +01:00
Linus Torvalds 051732bcbe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: check size of FUSE_NOTIFY_INVAL_ENTRY message
  fuse: mark pages accessed when written to
  fuse: delete dead .write_begin and .write_end aops
  fuse: fix flock
  fuse: fix non-ANSI void function notation
2011-08-24 09:14:42 -07:00
Johannes Weiner 478e0841b3 fuse: mark pages accessed when written to
As fuse does not use the page cache library functions when userspace
writes to a file, it did not benefit from 'c8236db mm: mark page
accessed before we write_end()' that made sure pages are properly
marked accessed when written to.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-08-08 16:08:08 +02:00
Johannes Weiner b40cdd56df fuse: delete dead .write_begin and .write_end aops
Ever since 'ea9b990 fuse: implement perform_write', the .write_begin
and .write_end aops have been dead code.

Their task - acquiring a page from the page cache, sending out a write
request and releasing the page again - is now done batch-wise to
maximize the number of pages send per userspace request.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-08-08 16:08:08 +02:00
Miklos Szeredi 37fb3a30b4 fuse: fix flock
Commit a9ff4f87 "fuse: support BSD locking semantics" overlooked a
number of issues with supporing flock locks over existing POSIX
locking infrastructure:

  - it's not backward compatible, passing flock(2) calls to userspace
    unconditionally (if userspace sets FUSE_POSIX_LOCKS)

  - it doesn't cater for the fact that flock locks are automatically
    unlocked on file release

  - it doesn't take into account the fact that flock exclusive locks
    (write locks) don't need an fd opened for write.

The last one invalidates the original premise of the patch that flock
locks can be emulated with POSIX locks.

This patch fixes the first two issues.  The last one needs to be fixed
in userspace if the filesystem assumed that a write lock will happen
only on a file operned for write (as in the case of the current fuse
library).

Reported-by: Sebastian Pipping <webmaster@hartwork.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-08-08 16:08:08 +02:00
Linus Torvalds 2dad3206db Merge branch 'for-3.1' of git://linux-nfs.org/~bfields/linux
* 'for-3.1' of git://linux-nfs.org/~bfields/linux:
  nfsd: don't break lease on CLAIM_DELEGATE_CUR
  locks: rename lock-manager ops
  nfsd4: update nfsv4.1 implementation notes
  nfsd: turn on reply cache for NFSv4
  nfsd4: call nfsd4_release_compoundargs from pc_release
  nfsd41: Deny new lock before RECLAIM_COMPLETE done
  fs: locks: remove init_once
  nfsd41: check the size of request
  nfsd41: error out when client sets maxreq_sz or maxresp_sz too small
  nfsd4: fix file leak on open_downgrade
  nfsd4: remember to put RW access on stateid destruction
  NFSD: Added TEST_STATEID operation
  NFSD: added FREE_STATEID operation
  svcrpc: fix list-corrupting race on nfsd shutdown
  rpc: allow autoloading of gss mechanisms
  svcauth_unix.c: quiet sparse noise
  svcsock.c: include sunrpc.h to quiet sparse noise
  nfsd: Remove deprecated nfsctl system call and related code.
  NFSD: allow OP_DESTROY_CLIENTID to be only op in COMPOUND

Fix up trivial conflicts in Documentation/feature-removal-schedule.txt
2011-07-25 22:49:19 -07:00
Josef Bacik 02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:59 -04:00
Josef Bacik 06222e491e fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
This converts everybody to handle SEEK_HOLE/SEEK_DATA properly.  In some cases
we just return -EINVAL, in others we do the normal generic thing, and in others
we're simply making sure that the properly due-dilligence is done.  For example
in NFS/CIFS we need to make sure the file size is update properly for the
SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself
that is all we have to do.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:58 -04:00
J. Bruce Fields 8fb47a4fbf locks: rename lock-manager ops
Both the filesystem and the lock manager can associate operations with a
lock.  Confusingly, one of them (fl_release_private) actually has the
same name in both operation structures.

It would save some confusion to give the lock-manager ops different
names.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-07-20 20:23:19 -04:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
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 5a18ec176c fuse: fix hang of single threaded fuseblk filesystem
Single threaded NTFS-3G could get stuck if a delayed RELEASE reply
triggered a DESTROY request via path_put().

Fix this by

 a) making RELEASE requests synchronous, whenever possible, on fuseblk
 filesystems

 b) if not possible (triggered by an asynchronous read/write) then do
 the path_put() in a separate thread with schedule_work().

Reported-by: Oliver Neukum <oneukum@suse.de>
Cc: stable@kernel.org
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2011-02-25 14:44:58 +01:00
Miklos Szeredi 1baa26b2be fuse: fix ioctl ABI
In kernel ABI version 7.16 and later FUSE_IOCTL_RETRY reply from a
unrestricted IOCTL request shall return with an array of 'struct
fuse_ioctl_iovec' instead of 'struct iovec'.  This fixes the ABI
ambiguity of 32bit vs. 64bit.

Reported-by: "ccmail111" <ccmail111@yahoo.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Tejun Heo <tj@kernel.org>
2010-12-07 20:16:56 +01:00
Miklos Szeredi 8ac835056c fuse: ioctl cleanup
Get rid of unnecessary page_address()-es.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Tejun Heo <tj@kernel.org>
2010-12-07 20:16:56 +01:00