Fix race in setting bitfields of fuse_conn. Spotted by Andrew Morton.
The two fields ->connected and ->mounted were always changed with the
fuse_lock held. But other bitfields in the same structure were changed
without the lock. In theory this could lead to losing the assignment of
even the ones under lock. The chosen solution is to change these two
fields to be a full unsigned type. The other bitfields aren't "important"
enough to warrant the extra complexity of full locking or changing them to
bitops.
For all bitfields document why they are safe wrt. concurrent
assignments.
Also make the initialization of the 'num_waiting' atomic counter explicit.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch changes fuse_readpages() to send READ requests asynchronously.
This makes it possible for userspace filesystems to utilize the kernel
readahead logic instead of having to implement their own (resulting in double
caching).
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a separate function for filling in the READ request. This will make it
possible to send asynchronous READ requests as well as synchronous ones.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now the INIT requests can be completely handled in inode.c and the
fuse_send_init() function need not be global any more.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add possibility for requests to run asynchronously and call an 'end' callback
when finished.
With this, the special handling of the INIT and RELEASE requests can be
cleaned up too.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add ability to abort a filesystem connection.
With the introduction of asynchronous reads, the ability to interrupt any
request is not enough to dissolve deadlocks, since now waiting for the request
completion (page unlocked) is independent of the actual request, so in a
deadlock all threads will be uninterruptible.
The solution is to make it possible to abort all requests, even those
currently undergoing I/O to/from userspace. The natural interface for this is
'mount -f mountpoint', but that only works as long as the filesystem is
attached. So also add an 'abort' attribute to the sysfs view of the
connection.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the 'waiting' attribute which indicates how many filesystem
requests are currently waiting to be completed. A non-zero value without any
filesystem activity indicates a hung or deadlocked filesystem.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kobjectify fuse_conn, and make it visible under /sys/fs/fuse/connections.
Lacking any natural naming, connections are numbered.
This patch doesn't add any attributes, just the infrastructure.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ->connected flag for a fuse_conn object previously only indicated whether
the device file for this connection is currently open or not.
Change it's meaning so that it indicates whether the connection is active or
not: now either umount or device release will clear the flag.
The separate ->mounted flag is still needed for handling background requests.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Create a new list for requests in the process of being transfered to/from
userspace. This will be needed to be able to abort all requests even those
currently under I/O
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The state of request was made up of 2 bitfields (->sent and ->finished) and of
the fact that the request was on a list or not.
Unify this into a single state field.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Inline keyword is unnecessary in most cases. Clean them up.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Handle the case when the INIT request is answered with an error.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This function used the request object after decrementing its reference count
and releasing the lock. This could in theory lead to all sorts of problems.
Fix and simplify at the same time.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fuse_copy_finish() must be called before request_end(), since the later might
sleep, and no sleeping is allowed between fuse_copy_one() and
fuse_copy_finish() because of kmap_atomic()/kunmap_atomic() used in them.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The Rio Karma portable MP3 player has its own proprietary partition table.
The partition layout is similar to a DOS boot sector but it begins at a
different offset and uses a different magic number (0xAB56 instead of
0xAA55). Add support for it to enable mounting the device.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
like other routines here, to ensure buffers are correctly initialised
with respect to b_private/b_end_io. Fixes an odd interaction between
XFS and reiserfs.
Signed-off-by: Nathan Scott <nathans@sgi.com>
Mark a few VFS functions as mandatory inline (based on Al Viro's request);
these must be inline due to stack usage issues during a recursive loop that
happens during the recursive symlink resolution (symlink to a symlink to a
symlink ..)
This patch at this point does not change behavior and is for documentation
purposes only (but this changes later in the series)
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Miklos Szeredi
Bob Copeland
Nathan Scott
Linus Torvalds
Nathan Scott
Arjan van de Ven