linux-toradex.git/fs/fuse, branch v3.10.5

fuse: readdirplus: sanity checks

2013-07-28T23:30:08+00:00

commit a28ef45cbb1e7fadd5159deb17b02de15c6e4aaf upstream.

Add sanity checks before adding or updating an entry with data received
from readdirplus.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: readdirplus: fix instantiate

2013-07-28T23:30:07+00:00

commit 2914941e3178d84a216fc4eb85292dfef3b6d628 upstream.

Fuse does instantiation slightly differently from NFS/CIFS which use
d_materialise_unique().

Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: readdirplus: fix dentry leak

2013-07-28T23:30:07+00:00

commit 53ce9a3364de0723b27d861de93bfc882f7db050 upstream.

In case d_lookup() returns a dentry with d_inode == NULL, the dentry is not
returned with dput(). This results in triggering a BUG() in
shrink_dcache_for_umount_subtree():

  BUG: Dentry ...{i=0,n=...} still in use (1) [unmount of fuse fuse]

[SzM: need to d_drop() as well]

Reported-by: Justin Clift 
Signed-off-by: Niels de Vos 
Signed-off-by: Miklos Szeredi 
Tested-by: Brian Foster 
Tested-by: Niels de Vos 
Signed-off-by: Greg Kroah-Hartman

fuse: hold i_mutex in fuse_file_fallocate()

2013-06-17T23:39:03+00:00

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 
Reviewed-by: Brian Foster 
Signed-off-by: Miklos Szeredi

fuse: fix alignment in short read optimization for async_dio

2013-06-03T13:15:42+00:00

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 
Reviewed-by: Brian Foster 
Signed-off-by: Miklos Szeredi

fuse: return -EIOCBQUEUED from fuse_direct_IO() for all async requests

2013-06-03T13:15:42+00:00

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 
Reviewed-by: Maxim Patlasov 
Signed-off-by: Miklos Szeredi

fuse: fix readdirplus Oops in fuse_dentry_revalidate

2013-06-03T12:40:22+00:00

Fix bug introduced by commit 4582a4ab2a "FUSE: Adapt readdirplus to application
usage patterns".

We need to check for a positive dentry; negative dentries are not added by
readdirplus.  Secondly we need to advise the use of readdirplus on the *parent*,
otherwise the whole thing is useless.  Thirdly all this is only relevant if
"readdirplus_auto" mode is selected by the filesystem.

We advise the use of readdirplus only if the dentry was still valid.  If we had
to redo the lookup then there was no use in doing the -plus version.

Reported-by: Bernd Schubert 
Signed-off-by: Miklos Szeredi 
CC: Feng Shuo 
CC: stable@vger.kernel.org

fuse: update inode size and invalidate attributes on fallocate

2013-05-20T14:58:58+00:00

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 
Signed-off-by: Miklos Szeredi

fuse: truncate pagecache range on hole punch

2013-05-20T14:58:57+00:00

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 
Signed-off-by: Miklos Szeredi

fuse: allocate for_background dio requests based on io->async state

2013-05-14T16:25:44+00:00

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 
Signed-off-by: Miklos Szeredi