Delete create_proc_read_entry() as it no longer has any users.
Also delete read_proc_t, write_proc_t, the read_proc member of the
proc_dir_entry struct and the support functions that use them. This saves a
pointer for every PDE allocated.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch binfmts that use ->read() to that (and to kernel_read()
in several cases in binfmt_flat - sure, it's nommu, but still,
doing ->read() into kmalloc'ed buffer...)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* serialize the call of ->release() on per-pdeo mutex
* don't remove pdeo from per-pde list until we are through with it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Switch huge if-statement in __proc_file_read() around. This then puts the
single line loop break immediately after the if-statement and allows us to
de-indent the huge comment and make it take fewer lines. The code following
the if-statement then follows naturally from the call to dp->read_proc().
Signed-off-by: David Howells <dhowells@redhat.com>
Kill create_proc_entry() in favour of create_proc_read_entry(), proc_create()
and proc_create_data().
Signed-off-by: David Howells <dhowells@redhat.com>
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data. Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Same as single_open(), but preallocates the buffer of given size.
Doesn't make any sense for sizes up to PAGE_SIZE and doesn't make
sense if output of show() exceeds PAGE_SIZE only rarely - seq_read()
will take care of growing the buffer and redoing show(). If you
_know_ that it will be large, it might make more sense to look into
saner iterator, rather than go with single-shot one. If that's
impossible, single_open_size() might be for you.
Again, don't use that without a good reason; occasionally that's really
the best way to go, but very often there are better solutions.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
it's used only as a flag to distinguish normal pipes/FIFOs from the
internal per-task one used by file-to-file splice. And pipe->files
would work just as well for that purpose...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/pipe.c file_operations methods *know* that pipe is not an internal one;
no need to check pipe->inode for those callers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new field - pipe->files; number of struct file over that pipe (all
sharing the same inode, of course); protected by inode->i_lock.
* pipe_release() decrements pipe->files, clears inode->i_pipe when
if the counter has reached 0 (all under ->i_lock) and, in that case,
frees pipe after having done pipe_unlock()
* fifo_open() starts with grabbing ->i_lock, and either bumps pipe->files
if ->i_pipe was non-NULL or allocates a new pipe (dropping and regaining
->i_lock) and rechecks ->i_pipe; if it's still NULL, inserts new pipe
there, otherwise bumps ->i_pipe->files and frees the one we'd allocated.
At that point we know that ->i_pipe is non-NULL and won't go away, so
we can do pipe_lock() on it and proceed as we used to. If we end up
failing, decrement pipe->files and if it reaches 0 clear ->i_pipe and
free the sucker after pipe_unlock().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* use the fact that file_inode(file)->i_pipe doesn't change
while the file is opened - no locks needed to access that.
* switch to pipe_lock/pipe_unlock where it's easy to do
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and provide namespace_lock() as a trivial wrapper;
switch to those two consistently.
Result is patterned after rtnl_lock/rtnl_unlock pair.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
global list of release_mounts() fodder, protected by namespace_sem;
eventually, all umount_tree() callers will use it as kill list.
Helper picking the contents of that list, releasing namespace_sem
and doing release_mounts() on what it got.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
do_loopback calls lock_mount(path) and forget to unlock_mount
if clone_mnt or copy_mnt fails.
[ 77.661566] ================================================
[ 77.662939] [ BUG: lock held when returning to user space! ]
[ 77.664104] 3.9.0-rc5+ #17 Not tainted
[ 77.664982] ------------------------------------------------
[ 77.666488] mount/514 is leaving the kernel with locks still held!
[ 77.668027] 2 locks held by mount/514:
[ 77.668817] #0: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffff811cca22>] lock_mount+0x32/0xe0
[ 77.671755] #1: (&namespace_sem){+++++.}, at: [<ffffffff811cca3a>] lock_mount+0x4a/0xe0
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
just what it sounds like; do that only to procfs subtrees you've
created - doing that to something shared with another driver is
not only antisocial, but might cause interesting races with
proc_create() and its ilk.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull vfs fixes from Al Viro:
"stable fodder; assorted deadlock fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vt: synchronize_rcu() under spinlock is not nice...
Nest rename_lock inside vfsmount_lock
Don't bother with redoing rw_verify_area() from default_file_splice_from()
... lest we get livelocks between path_is_under() and d_path() and friends.
The thing is, wrt fairness lglocks are more similar to rwsems than to rwlocks;
it is possible to have thread B spin on attempt to take lock shared while thread
A is already holding it shared, if B is on lower-numbered CPU than A and there's
a thread C spinning on attempt to take the same lock exclusive.
As the result, we need consistent ordering between vfsmount_lock (lglock) and
rename_lock (seq_lock), even though everything that takes both is going to take
vfsmount_lock only shared.
Spotted-by: Brad Spengler <spender@grsecurity.net>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- Fix an NFSv4 idmapper regression
- Fix an Oops in the pNFS blocks client
- Fix up various issues with pNFS layoutcommit
- Ensure correct read ordering of variables in rpc_wake_up_task_queue_locked
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Merge tag 'nfs-for-3.9-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
- Fix an NFSv4 idmapper regression
- Fix an Oops in the pNFS blocks client
- Fix up various issues with pNFS layoutcommit
- Ensure correct read ordering of variables in
rpc_wake_up_task_queue_locked
* tag 'nfs-for-3.9-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
SUNRPC: Add barriers to ensure read ordering in rpc_wake_up_task_queue_locked
NFSv4.1: Add a helper pnfs_commit_and_return_layout
NFSv4.1: Always clear the NFS_INO_LAYOUTCOMMIT in layoutreturn
NFSv4.1: Fix a race in pNFS layoutcommit
pnfs-block: removing DM device maybe cause oops when call dev_remove
NFSv4: Fix the string length returned by the idmapper
