linux-toradex.git/fs/fuse/inode.c, branch v2.6.19.2

[PATCH] fuse: fix handling of moved directory

2006-10-17T15:18:45+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fuse: fix spurious BUG

2006-10-17T15:18:45+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fuse: locking fix for nlookup

2006-10-17T15:18:45+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fuse: fix hang on SMP

2006-10-17T15:18:45+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fuse: use dentry in statfs

2006-09-29T16:18:08+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] inode-diet: Eliminate i_blksize from the inode structure

2006-09-27T15:26:18+00:00

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" 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fuse: use jiffies_64

2006-07-31T20:28:43+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge git://git.linux-nfs.org/pub/linux/nfs-2.6

2006-06-25T17:54:14+00:00

* 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
  ...

[PATCH] fuse: scramble lock owner ID

2006-06-25T17:01:20+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fuse: add request interruption

2006-06-25T17:01:19+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds