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>
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>
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>
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>
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>
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>
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>
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>
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>
The spufs file system creates files in a directory before instantiating the
directory itself, which causes a NULL pointer access in
inotify_d_instantiate since c32ccd87bf.
I'd like to keep this behavior since it means that the user will not have
access to files in the directory before I know that I succeed in creating
everything in it. This patch adds a simple check for the inode to keep
that working.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Everybody seems to be using /proc/vmcore as a method to access the kernel
crash dump. Hence probably it makes sense to enable CONFIG_PROC_VMCORE by
default if CONFIG_CRASH_DUMP is selected. This makes kdump configuration
further easier for a user.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The only record we have of the real-time age of a process, regardless of
execs it's done, is start_time. When a non-leader thread exec, the
original start_time of the process is lost. Things looking at the
real-time age of the process are fooled, for example the process accounting
record when the process finally dies. This change makes the oldest
start_time stick around with the process after a non-leader exec. This way
the association between PID and start_time is kept constant, which seems
correct to me.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As reported by Michael Kerrisk, POLLRDHUP handling was not consistent
between epoll and poll/select, since in epoll it was unmaskeable. This
patch brings uniformity in POLLRDHUP handling.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A couple of /proc/vmcore data structures overflow with 32bit systems having
memory more than 4G. This patch fixes those.
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If SELECT_STACK_ALLOC is not a multiple of sizeof(long) then stack_fds[]
would be shorter than SELECT_STACK_ALLOC bytes and could overflow later in
the function. Fixed by simply rearranging the test later to work on
sizeof(stack_fds) Currently SELECT_STACK_ALLOC is 256 so this doesn't
happen, but it's nasty to have things like this hidden in the code. What
if later someone decides to change SELECT_STACK_ALLOC to 300?
Signed-off-by: Mitchell Blank Jr <mitch@sfgoth.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Handle a failing sget() in v9fs_get_sb().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The mnt_flags are propagated into do_loopback(), so that they can be stored
with the vfsmount
Signed-off-by: Herbert Poetzl <herbert@13thfloor.at>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ulrich suggested that the `flags' arg to sync_file_range() become unsigned.
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce GFP_NOWAIT, as an alias for GFP_ATOMIC & ~__GFP_HIGH.
This also changes XFS, which is the only in-tree user of this idiom that I
could find. The XFS piece is compile-tested only.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Acked-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/select.c: In function `core_sys_select':
fs/select.c:339: warning: assignment from incompatible pointer type
fs/select.c:376: warning: comparison of distinct pointer types lacks a cast
By using a void* we can remove lots of casts rather than adding more.
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
that have been unlinked, we may need to execute transactions during
reclaim. By the time the transaction has hit the disk, the linux inode and
xfs vnode may already have been freed so we can't reference them safely.
Use the known xfs inode state to determine if it is safe to reference the
vnode and linux inode during the unpin operation.
SGI-PV: 946321
SGI-Modid: xfs-linux-melb:xfs-kern:25687a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
millions of inodes cached and has sparse cluster population, removing
inodes from the cluster hash consumes excessive amounts of CPU time.
Reduce the CPU cost by making removal O(1) via use of a double linked list
for the hash chains.
SGI-PV: 951551
SGI-Modid: xfs-linux-melb:xfs-kern:25683a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
nonblock mode with the new IO path code (since 2.6.16).
SGI-PV: 951662
SGI-Modid: xfs-linux-melb:xfs-kern:25676a
Signed-off-by: Nathan Scott <nathans@sgi.com>
* 'upstream-linus' of git://oss.oracle.com/home/sourcebo/git/ocfs2:
[PATCH] CONFIGFS_FS must depend on SYSFS
[PATCH] Bogus NULL pointer check in fs/configfs/dir.c
ocfs2: Better I/O error handling in heartbeat
ocfs2: test and set teardown flag early in user_dlm_destroy_lock()
ocfs2: Handle the DLM_CANCELGRANT case in user_unlock_ast()
ocfs2: catch an invalid ast case in dlmfs
ocfs2: remove an overly aggressive BUG() in dlmfs
ocfs2: multi node truncate fix
Oleg Nesterov spotted two interesting bugs with the current de_thread
code. The simplest is a long standing double decrement of
__get_cpu_var(process_counts) in __unhash_process. Caused by
two processes exiting when only one was created.
The other is that since we no longer detach from the thread_group list
it is possible for do_each_thread when run under the tasklist_lock to
see the same task_struct twice. Once on the task list as a
thread_group_leader, and once on the thread list of another
thread.
The double appearance in do_each_thread can cause a double increment
of mm_core_waiters in zap_threads resulting in problems later on in
coredump_wait.
To remedy those two problems this patch takes the simple approach
of changing the old thread group leader into a child thread.
The only routine in release_task that cares is __unhash_process,
and it can be trivially seen that we handle cleaning up a
thread group leader properly.
Since de_thread doesn't change the pid of the exiting leader process
and instead shares it with the new leader process. I change
thread_group_leader to recognize group leadership based on the
group_leader field and not based on pids. This should also be
slightly cheaper then the existing thread_group_leader macro.
I performed a quick audit and I couldn't see any user of
thread_group_leader that cared about the difference.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes the a compile error with CONFIG_SYSFS=n
Configfs is creating, as a matter of policy, the /sys/kernel/config
mountpoint. This means it requires CONFIG_SYSFS.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
We check the "group" pointer after we dereference it. This check is
bogus, as it cannot be NULL coming in.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Propagate errors received in o2hb_bio_end_io() back to the heartbeat thread
so it can skip re-arming the timer.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Remove the code which attempted to catch it via dlmunlock() return status -
this never happens there.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Don't BUG() user_dlm_unblock_lock() on the absence of the USER_LOCK_BLOCKED
flag - this turns out to be a valid case. Make some of the related BUG()
statements print more useful information.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Fix ocfs2_truncate_file() so that it forces a truncate_inode_pages() on all
interested nodes in all cases of a truncate(), not just allocation change.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Originally from Nick Piggin, just adapted to the newer branch.
You can't check PageLRU without holding zone->lru_lock. The page
release code can get away with it only because the page refcount is 0 at
that point. Also, you can't reliably remove pages from the LRU unless
the refcount is 0. Ever.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Jens Axboe <axboe@suse.de>
Thanks to Andrew for the good explanation of why this is so. akpm writes:
If a page is under writeback and we remove it from pagecache, it's still
going to get written to disk. But the VFS no longer knows about that page,
nor that this page is about to modify disk blocks.
So there might be scenarios in which those
blocks-which-are-about-to-be-written-to get reused for something else.
When writeback completes, it'll scribble on those blocks.
This won't happen in ext2/ext3-style filesystems in normal mode because the
page has buffers and try_to_release_page() will fail.
But ext2 in nobh mode doesn't attach buffers at all - it just sticks the
page in a BIO, finds some new blocks, points the BIO at those blocks and
lets it rip.
While that write IO's in flight, someone could truncate the file. Truncate
won't block on the writeout because the page isn't in pagecache any more.
So truncate will the free the blocks from the file under the page's feet.
Then something else can reallocate those blocks. Then write data to them.
Now, the original write completes, corrupting the filesystem.
Signed-off-by: Jens Axboe <axboe@suse.de>
By cleaning up the writeback logic (killing write_one_page() and the manual
set_page_dirty()), we can get rid of ->stolen inside the pipe_buffer and
just keep it local in pipe_to_file().
This also adds dirty page balancing logic and O_SYNC handling.
Signed-off-by: Jens Axboe <axboe@suse.de>
Clear the entire range, and don't increment pidx or we keep filling
the same position again and again.
Thanks to KAMEZAWA Hiroyuki.
Signed-off-by: Jens Axboe <axboe@suse.de>
* git://oss.sgi.com:8090/oss/git/xfs-2.6:
[XFS] Provide XFS support for the splice syscall.
[XFS] Reenable write barriers by default.
[XFS] Make project quota enforcement return an error code consistent with
[XFS] Implement the silent parameter to fill_super, previously ignored.
[XFS] Cleanup comment to remove reference to obsoleted function
No one should be writing a PAGE_SIZE worth of data to a normal sysfs
file, so properly terminate the buffer.
Thanks to Al Viro for pointing out my supidity here.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (48 commits)
Documentation: fix minor kernel-doc warnings
BUG_ON() Conversion in drivers/net/
BUG_ON() Conversion in drivers/s390/net/lcs.c
BUG_ON() Conversion in mm/slab.c
BUG_ON() Conversion in mm/highmem.c
BUG_ON() Conversion in kernel/signal.c
BUG_ON() Conversion in kernel/signal.c
BUG_ON() Conversion in kernel/ptrace.c
BUG_ON() Conversion in ipc/shm.c
BUG_ON() Conversion in fs/freevxfs/
BUG_ON() Conversion in fs/udf/
BUG_ON() Conversion in fs/sysv/
BUG_ON() Conversion in fs/inode.c
BUG_ON() Conversion in fs/fcntl.c
BUG_ON() Conversion in fs/dquot.c
BUG_ON() Conversion in md/raid10.c
BUG_ON() Conversion in md/raid6main.c
BUG_ON() Conversion in md/raid5.c
Fix minor documentation typo
BFP->BPF in Documentation/networking/tuntap.txt
...
It doesn't make the splice itself necessarily nonblocking (because the
actual file descriptors that are spliced from/to may block unless they
have the O_NONBLOCK flag set), but it makes the splice pipe operations
nonblocking.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch updates the comments to match the actual code.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
