Commit graph

109 commits

Author SHA1 Message Date
Miklos Szeredi
2d51013ed2 [PATCH] fuse: fix Oops in lookup
Fix bug in certain error paths of lookup routines.  The request object was
reused for sending FORGET, which is illegal.  This bug could cause an Oops
in 2.6.18.  In earlier versions it might silently corrupt memory, but this
is very unlikely.

These error paths are never triggered by libfuse, so this wasn't noticed
even with the 2.6.18 kernel, only with a filesystem using the raw kernel
interface.

Thanks to Russ Cox for the bug report and test filesystem.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-25 13:28:33 -08:00
OGAWA Hirofumi
2e990021bf [PATCH] fuse: ->readpages() cleanup
This just ignore the remaining pages.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-03 12:27:57 -08:00
Miklos Szeredi
e956edd052 [PATCH] fuse: fix dereferencing dentry parent
There's no locking for ->d_revalidate, so fuse_dentry_revalidate() should use
dget_parent() instead of simply dereferencing ->d_parent.

Due to topology changes in the directory tree the parent could become negative
or be destroyed while being used.  There hasn't been any reports about this
yet.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:45 -07:00
Miklos Szeredi
d2a85164aa [PATCH] fuse: fix handling of moved directory
Fuse considered it an error (EIO) if lookup returned a directory inode, to
which a dentry already refered.  This is because directory aliases are not
allowed.

But in a network filesystem this could happen legitimately, if a directory is
moved on a remote client.  This patch attempts to relax the restriction by
trying to first evict the offending alias from the cache.  If this fails, it
still returns an error (EBUSY).

A rarer situation is if an mkdir races with an indenpendent lookup, which
finds the newly created directory already moved.  In this situation the mkdir
should return success, but that would be incorrect, since the dentry cannot be
instantiated, so return EBUSY.

Previously checking for a directory alias and instantiation of the dentry
weren't done atomically in lookup/mkdir, hence two such calls racing with each
other could create aliased directories.  To prevent this introduce a new
per-connection mutex: fuse_conn->inst_mutex, which is taken for instantiations
with a directory inode.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:45 -07:00
Miklos Szeredi
265126ba9e [PATCH] fuse: fix spurious BUG
Fix a spurious BUG in an unlikely race, where at least three parallel lookups
return the same inode, but with different file type.  This has not yet been
observed in real life.

Allowing unlimited retries could delay fuse_iget() indefinitely, but this is
really for the broken userspace filesystem to worry about.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:45 -07:00
Miklos Szeredi
8da5ff23ce [PATCH] fuse: locking fix for nlookup
An inode could be returned by independent parallel lookups, in this case an
update of the lookup counter could be lost resulting in a memory leak in
userspace.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:45 -07:00
Miklos Szeredi
9ffbb91623 [PATCH] fuse: fix hang on SMP
Fuse didn't always call i_size_write() with i_mutex held which caused rare
hangs on SMP/32bit.  This bug has been present since fuse-2.2, well before
being merged into mainline.

The simplest solution is to protect i_size_write() with the per-connection
spinlock.  Using i_mutex for this purpose would require some restructuring of
the code and I'm not even sure it's always safe to acquire i_mutex in all
places i_size needs to be set.

Since most of vmtruncate is already duplicated for other reasons, duplicate
the remaining part as well, making all i_size_write() calls internal to fuse.

Using i_size_write() was unnecessary in fuse_init_inode(), since this function
is only called on a newly created locked inode.

Reported by a few people over the years, but special thanks to Dana Henriksen
who was persistent enough in helping me debug it.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:45 -07:00
Dave Hansen
ce71ec3684 [PATCH] r/o bind mounts: monitor zeroing of i_nlink
Some filesystems, instead of simply decrementing i_nlink, simply zero it
during an unlink operation.  We need to catch these in addition to the
decrement operations.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:30 -07:00
Dave Hansen
d8c76e6f45 [PATCH] r/o bind mount prepwork: inc_nlink() helper
This is mostly included for parity with dec_nlink(), where we will have some
more hooks.  This one should stay pretty darn straightforward for now.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:30 -07:00
Badari Pulavarty
543ade1fc9 [PATCH] Streamline generic_file_* interfaces and filemap cleanups
This patch cleans up generic_file_*_read/write() interfaces.  Christoph
Hellwig gave me the idea for this clean ups.

In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods.  This allows us
to cleanup all variants of generic_file_* routines.

Final available interfaces:

generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler

__generic_file_aio_write_nolock() - internal worker routine

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:28 -07:00
Badari Pulavarty
ee0b3e671b [PATCH] Remove readv/writev methods and use aio_read/aio_write instead
This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:28 -07:00
Miklos Szeredi
650a898342 [PATCH] vfs: define new lookup flag for chdir
In the "operation does permission checking" model used by fuse, chdir
permission is not checked, since there's no chdir method.

For this case set a lookup flag, which will be passed to ->permission(), so
fuse can distinguish it from permission checks for other operations.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:08 -07:00
Miklos Szeredi
5b35e8e58a [PATCH] fuse: use dentry in statfs
Some filesystems may want to report different values depending on the path
within the filesystem, i.e.  one mount is actually several filesystems.  This
can be the case for a network filesystem exported by an unprivileged server
(e.g.  sshfs).

This is now possible, thanks to David Howells "VFS: Permit filesystem to
perform statfs with a known root dentry" patch.

This change is backward compatible, so no need to change interface version.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:08 -07:00
Josh Triplett
105f4d7a81 [PATCH] fuse: add lock annotations to request_end and fuse_read_interrupt
request_end and fuse_read_interrupt release fc->lock.  Add lock annotations
to these two functions so that sparse can check callers for lock pairing,
and so that sparse will not complain about these functions since they
intentionally use locks in this manner.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:08 -07:00
Theodore Ts'o
ba52de123d [PATCH] inode-diet: Eliminate i_blksize from the inode structure
This eliminates the i_blksize field from struct inode.  Filesystems that want
to provide a per-inode st_blksize can do so by providing their own getattr
routine instead of using the generic_fillattr() function.

Note that some filesystems were providing pretty much random (and incorrect)
values for i_blksize.

[bunk@stusta.de: cleanup]
[akpm@osdl.org: generic_fillattr() fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:18 -07:00
Theodore Ts'o
8e18e2941c [PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private
The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86.  (It would be more on an x86_64 system).  This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).

This patch:

The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer.  Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer.  This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.

[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:17 -07:00
Alexander Zarochentsev
1d7ea7324a [PATCH] fuse: fix error case in fuse_readpages
Don't let fuse_readpages leave the @pages list not empty when exiting
on error.

[akpm@osdl.org: kernel-doc fixes]
Signed-off-by: Alexander Zarochentsev <zam@namesys.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:29 -07:00
Miklos Szeredi
873302c71c [PATCH] fuse: fix typo
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:43 -07:00
Miklos Szeredi
0a0898cf41 [PATCH] fuse: use jiffies_64
It is entirely possible (though rare) that jiffies half-wraps around, while a
dentry/inode remains in the cache.  This could mean that the dentry/inode is
not invalidated for another half wraparound-time.

To get around this problem, use 64-bit jiffies.  The only problem with this is
that dentry->d_time is 32 bits on 32-bit archs.  So use d_fsdata as the high
32 bits.  This is an ugly hack, but far simpler, than having to allocate
private data just for this purpose.

Since 64-bit jiffies can be assumed never to wrap around, simple comparison
can be used, and a zero time value can represent "invalid".

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:43 -07:00
Miklos Szeredi
685d16ddb0 [PATCH] fuse: fix zero timeout
An attribute and entry timeout of zero should mean, that the entity is
invalidated immediately after the operation.  Previously invalidation only
happened at the next clock tick.

Reported and tested by Craig Davies.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:43 -07:00
Christoph Hellwig
f5e54d6e53 [PATCH] mark address_space_operations const
Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28 14:59:04 -07:00
Linus Torvalds
1d77062b14 Merge git://git.linux-nfs.org/pub/linux/nfs-2.6
* git://git.linux-nfs.org/pub/linux/nfs-2.6: (51 commits)
  nfs: remove nfs_put_link()
  nfs-build-fix-99
  git-nfs-build-fixes
  Merge branch 'odirect'
  NFS: alloc nfs_read/write_data as direct I/O is scheduled
  NFS: Eliminate nfs_get_user_pages()
  NFS: refactor nfs_direct_free_user_pages
  NFS: remove user_addr, user_count, and pos from nfs_direct_req
  NFS: "open code" the NFS direct write rescheduler
  NFS: Separate functions for counting outstanding NFS direct I/Os
  NLM: Fix reclaim races
  NLM: sem to mutex conversion
  locks.c: add the fl_owner to nlm_compare_locks
  NFS: Display the chosen RPCSEC_GSS security flavour in /proc/mounts
  NFS: Split fs/nfs/inode.c
  NFS: Fix typo in nfs_do_clone_mount()
  NFS: Fix compile errors introduced by referrals patches
  NFSv4: Ensure that referral mounts bind to a reserved port
  NFSv4: A root pathname is sent as a zero component4
  NFSv4: Follow a referral
  ...
2006-06-25 10:54:14 -07:00
Miklos Szeredi
9c8ef5614d [PATCH] fuse: scramble lock owner ID
VFS uses current->files pointer as lock owner ID, and it wouldn't be
prudent to expose this value to userspace.  So scramble it with XTEA using
a per connection random key, known only to the kernel.  Only one direction
needs to be implemented, since the ID is never sent in the reverse
direction.

The XTEA algorithm is implemented inline since it's simple enough to do so,
and this adds less complexity than if the crypto API were used.

Thanks to Jesper Juhl for the idea.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:20 -07:00
Miklos Szeredi
a4d27e75ff [PATCH] fuse: add request interruption
Add synchronous request interruption.  This is needed for file locking
operations which have to be interruptible.  However filesystem may implement
interruptibility of other operations (e.g.  like NFS 'intr' mount option).

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:19 -07:00
Miklos Szeredi
f9a2842e56 [PATCH] fuse: rename the interrupted flag
Rename the 'interrupted' flag to 'aborted', since it indicates exactly that,
and next patch will introduce an 'interrupted' flag for a

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:19 -07:00
Miklos Szeredi
33649c91a3 [PATCH] fuse: ensure FLUSH reaches userspace
All POSIX locks owned by the current task are removed on close().  If the
FLUSH request resulting initiated by close() fails to reach userspace, there
might be locks remaining, which cannot be removed.

The only reason it could fail, is if allocating the request fails.  In this
case use the request reserved for RELEASE, or if that is currently used by
another FLUSH, wait for it to become available.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:19 -07:00
Miklos Szeredi
7142125937 [PATCH] fuse: add POSIX file locking support
This patch adds POSIX file locking support to the fuse interface.

This implementation doesn't keep any locking state in kernel.  Unlocking on
close() is handled by the FLUSH message, which now contains the lock owner id.

Mandatory locking is not supported.  The filesystem may enfoce mandatory
locking in userspace if needed.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:19 -07:00
Miklos Szeredi
bafa96541b [PATCH] fuse: add control filesystem
Add a control filesystem to fuse, replacing the attributes currently exported
through sysfs.  An empty directory '/sys/fs/fuse/connections' is still created
in sysfs, and mounting the control filesystem here provides backward
compatibility.

Advantages of the control filesystem over the previous solution:

  - allows the object directory and the attributes to be owned by the
    filesystem owner, hence letting unpriviled users abort the
    filesystem connection

  - does not suffer from module unload race

[akpm@osdl.org: fix this fs for recent dhowells depredations]
[akpm@osdl.org: fix 64-bit printk warnings]
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:19 -07:00
Miklos Szeredi
51eb01e735 [PATCH] fuse: no backgrounding on interrupt
Don't put requests into the background when a fatal interrupt occurs while the
request is in userspace.  This removes a major wart from the implementation.

Backgrounding of requests was introduced to allow breaking of deadlocks.
However now the same can be achieved by aborting the filesystem through the
'abort' sysfs attribute.

This is a change in the interface, but should not cause problems, since these
kinds of deadlocks never happen during normal operation.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:19 -07:00
Trond Myklebust
816724e65c Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
Conflicts:

	fs/nfs/inode.c
	fs/super.c

Fix conflicts between patch 'NFS: Split fs/nfs/inode.c' and patch
'VFS: Permit filesystem to override root dentry on mount'
2006-06-24 13:07:53 -04:00
Miklos Szeredi
75e1fcc0b1 [PATCH] vfs: add lock owner argument to flush operation
Pass the POSIX lock owner ID to the flush operation.

This is useful for filesystems which don't want to store any locking state
in inode->i_flock but want to handle locking/unlocking POSIX locks
internally.  FUSE is one such filesystem but I think it possible that some
network filesystems would need this also.

Also add a flag to indicate that a POSIX locking request was generated by
close(), so filesystems using the above feature won't send an extra locking
request in this case.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:02 -07:00
David Howells
726c334223 [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry
Give the statfs superblock operation a dentry pointer rather than a superblock
pointer.

This complements the get_sb() patch.  That reduced the significance of
sb->s_root, allowing NFS to place a fake root there.  However, NFS does
require a dentry to use as a target for the statfs operation.  This permits
the root in the vfsmount to be used instead.

linux/mount.h has been added where necessary to make allyesconfig build
successfully.

Interest has also been expressed for use with the FUSE and XFS filesystems.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:45 -07:00
David Howells
454e2398be [PATCH] VFS: Permit filesystem to override root dentry on mount
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:45 -07:00
Trond Myklebust
8b512d9a88 VFS: Remove dependency of ->umount_begin() call on MNT_FORCE
Allow filesystems to decide to perform pre-umount processing whether or not
MNT_FORCE is set.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-06-09 09:34:18 -04:00
Miklos Szeredi
8aa09a50b5 [fuse] fix race between checking and setting file->private_data
BKL does not protect against races if the task may sleep between
checking and setting a value.  So move checking of file->private_data
near to setting it in fuse_fill_super().

Found by Al Viro.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-26 10:49:16 +02:00
Miklos Szeredi
6dbbcb1205 [fuse] fix deadlock between fuse_put_super() and request_end(), try #2
A deadlock was possible, when the last reference to the superblock was
held due to a background request containing a file reference.

Releasing the file would release the vfsmount which in turn would
release the superblock.  Since sbput_sem is held during the fput() and
fuse_put_super() tries to acquire this same semaphore, a deadlock
results.

The solution is to move the fput() outside the region protected by
sbput_sem.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-26 10:49:06 +02:00
Miklos Szeredi
5a5fb1ea74 Revert "[fuse] fix deadlock between fuse_put_super() and request_end()"
This reverts 73ce8355c2 commit.

It was wrong, because it didn't take into account the requirement,
that iput() for background requests must be performed synchronously
with ->put_super(), otherwise active inodes may remain after unmount.

The right solution is to keep the sbput_sem and perform iput() within
the locked region, but move fput() outside sbput_sem.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-26 10:48:55 +02:00
Miklos Szeredi
56cf34ff07 [fuse] Direct I/O should not use fuse_reset_request
It's cleaner to allocate a new request, otherwise the uid/gid/pid
fields of the request won't be filled in.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11 21:16:51 +02:00
Miklos Szeredi
4858cae4f0 [fuse] Don't init request twice
Request is already initialized in fuse_request_alloc() so no need to
do it again in fuse_get_req().

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11 21:16:38 +02:00
Miklos Szeredi
9bc5dddad1 [fuse] Fix accounting the number of waiting requests
Properly accounting the number of waiting requests was forgotten in
"clean up request accounting" patch.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11 21:16:09 +02:00
Miklos Szeredi
73ce8355c2 [fuse] fix deadlock between fuse_put_super() and request_end()
A deadlock was possible, when the last reference to the superblock was
held due to a background request containing a file reference.

Releasing the file would release the vfsmount which in turn would
release the superblock.  Since sbput_sem is held during the fput() and
fuse_put_super() tries to acquire this same semaphore, a deadlock
results.

The chosen soltuion is to get rid of sbput_sem, and instead use the
spinlock to ensure the referenced inodes/file are released only once.
Since the actual release may sleep, defer these outside the locked
region, but using local variables instead of the structure members.

This is a much more rubust solution.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11 21:14:26 +02:00
Miklos Szeredi
08a53cdce6 [PATCH] fuse: account background requests
The previous patch removed limiting the number of outstanding requests.  This
patch adds a much simpler limiting, that is also compatible with file locking
operations.

A task may have at most one synchronous request allocated.  So these requests
need not be otherwise limited.

However the number of background requests (release, forget, asynchronous
reads, interrupted requests) can grow indefinitely.  This can be used by a
malicous user to cause FUSE to allocate arbitrary amounts of unswappable
kernel memory, denying service.

For this reason add a limit for the number of background requests, and block
allocations of new requests until the number goes bellow the limit.

Also use this mechanism to block all requests until the INIT reply is
received.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:49 -07:00
Miklos Szeredi
ce1d5a491f [PATCH] fuse: clean up request accounting
FUSE allocated most requests from a fixed size pool filled at mount time.
However in some cases (release/forget) non-pool requests were used.  File
locking operations aren't well served by the request pool, since they may
block indefinetly thus exhausting the pool.

This patch removes the request pool and always allocates requests on demand.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:49 -07:00
Miklos Szeredi
a87046d822 [PATCH] fuse: consolidate device errors
Return consistent error values for the case when the opened device file has no
mount associated yet.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:48 -07:00
Miklos Szeredi
d713311464 [PATCH] fuse: use a per-mount spinlock
Remove the global spinlock in favor of a per-mount one.

This patch is basically find & replace.  The difficult part has already been
done by the previous patch.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:48 -07:00
Miklos Szeredi
0720b31597 [PATCH] fuse: simplify locking
This is in preparation for removing the global spinlock in favor of a
per-mount one.

The only critical part is the interaction between fuse_dev_release() and
fuse_fill_super(): fuse_dev_release() must see the assignment to
file->private_data, otherwise it will leak the reference to fuse_conn.

This is ensured by the fput() operation, which will synchronize the assignment
with other CPU's that may do a final fput() soon after this.

Also redundant locking is removed from fuse_fill_super(), where exclusion is
already ensured by the BKL held for this function by the VFS.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:48 -07:00
Jeff Dike
e5ac1d1e70 [PATCH] fuse: add O_NONBLOCK support to FUSE device
I don't like duplicating the connected and list_empty tests in fuse_dev_readv,
but this seemed cleaner than adding the f_flags test to request_wait.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:48 -07:00
Jeff Dike
385a17bfc3 [PATCH] fuse: add O_ASYNC support to FUSE device
This adds asynchronous notification to FUSE - a FUSE server can request
O_ASYNC on a /dev/fuse file descriptor and receive SIGIO when there is input
available.

One subtlety - fuse_dev_fasync, which is called when O_ASYNC is requested,
does no locking, unlink the other methods.  I think it's unnecessary, as the
fuse_conn.fasync list is manipulated only by fasync_helper and kill_fasync,
which provide their own locking.  It would also be wrong to use the fuse_lock,
as it's a spin lock and fasync_helper can sleep.  My one concern with this is
the fuse_conn going away underneath fuse_dev_fasync - sys_fcntl takes a
reference on the file struct, so this seems not to be a problem.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:48 -07:00
Miklos Szeredi
7025d9ad10 [PATCH] fuse: fix fuse_dev_poll() return value
fuse_dev_poll() returned an error value instead of a poll mask.  Luckily (or
unluckily) -ENODEV does contain the POLLERR bit.

There's also a race if filesystem is unmounted between fuse_get_conn() and
spin_lock(), in which case this event will be missed by poll().

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:47 -07:00
Miklos Szeredi
d3406ffa4a [PATCH] fuse: fix oops in fuse_send_readpages()
During heavy parallel filesystem activity it was possible to Oops the kernel.
The reason is that read_cache_pages() could skip pages which have already been
inserted into the cache by another task.  Occasionally this may result in zero
pages actually being sent, while fuse_send_readpages() relies on at least one
page being in the request.

So check this corner case and just free the request instead of trying to send
it.

Reported and tested by Konstantin Isakov.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:47 -07:00