It works like this:
Open the file
Read all the contents.
Call poll requesting POLLERR or POLLPRI (so select/exceptfds works)
When poll returns,
close the file and go to top of loop.
or lseek to start of file and go back to the 'read'.
Events are signaled by an object manager calling
sysfs_notify(kobj, dir, attr);
If the dir is non-NULL, it is used to find a subdirectory which
contains the attribute (presumably created by sysfs_create_group).
This has a cost of one int per attribute, one wait_queuehead per kobject,
one int per open file.
The name "sysfs_notify" may be confused with the inotify
functionality. Maybe it would be nice to support inotify for sysfs
attributes as well?
This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action
to be pollable
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/mszeredi/fuse:
[fuse] Direct I/O should not use fuse_reset_request
[fuse] Don't init request twice
[fuse] Fix accounting the number of waiting requests
[fuse] fix deadlock between fuse_put_super() and request_end()
* 'tee' of git://brick.kernel.dk/data/git/linux-2.6-block:
[PATCH] splice: add support for sys_tee()
[PATCH] splice: pass offset around for ->splice_read() and ->splice_write()
This is two distinct changes.
- Not changing our real parents.
- Not changing our ptrace parents.
Not changing our real parents is trivially correct because both tasks
have the same real parents as they are part of a thread group. Now that
we demote the leader to a thread there is no longer any reason to change
it's parentage.
Not changing our ptrace parents is a user visible change if someone
looks hard enough. I don't think user space applications will care or
even notice.
In the practical and I think common case a debugger will have attached
to all of the threads using the same ptrace flags. From my quick skim
of strace and gdb that appears to be the case. Which if true means
debuggers will not notice a change.
Before this point we have already generated a ptrace event in do_exit
that reports the leaders pid has died so de_thread is visible to a
debugger. Which means attempting to hide this case by copying flags
around appears excessive.
By not doing anything it avoids all of the weird locking issues between
de_thread and ptrace attach, and removes one case from consideration for
fixing the ptrace locking.
This only addresses Oleg's first concern with ptrace_attach, that of the
problems caused by reparenting. Oleg's second concern is essentially a
race between ptrace_attach and release_task that causes an oops when we
get to force_sig_specific. There is nothing special about de_thread
with respect to that race.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It's cleaner to allocate a new request, otherwise the uid/gid/pid
fields of the request won't be filled in.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Properly accounting the number of waiting requests was forgotten in
"clean up request accounting" patch.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
A deadlock was possible, when the last reference to the superblock was
held due to a background request containing a file reference.
Releasing the file would release the vfsmount which in turn would
release the superblock. Since sbput_sem is held during the fput() and
fuse_put_super() tries to acquire this same semaphore, a deadlock
results.
The chosen soltuion is to get rid of sbput_sem, and instead use the
spinlock to ensure the referenced inodes/file are released only once.
Since the actual release may sleep, defer these outside the locked
region, but using local variables instead of the structure members.
This is a much more rubust solution.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Basically an in-kernel implementation of tee, which uses splice and the
pipe buffers as an intelligent way to pass data around by reference.
Where the user space tee consumes the input and produces a stdout and
file output, this syscall merely duplicates the data inside a pipe to
another pipe. No data is copied, the output just grabs a reference to the
input pipe data.
Signed-off-by: Jens Axboe <axboe@suse.de>
We need not use ->f_pos as the offset for the file input/output. If the
user passed an offset pointer in through sys_splice(), just use that and
leave ->f_pos alone.
Signed-off-by: Jens Axboe <axboe@suse.de>
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
[PATCH] vfs: add splice_write and splice_read to documentation
[PATCH] Remove sys_ prefix of new syscalls from __NR_sys_*
[PATCH] splice: warning fix
[PATCH] another round of fs/pipe.c cleanups
[PATCH] splice: comment styles
[PATCH] splice: add Ingo as addition copyright holder
[PATCH] splice: unlikely() optimizations
[PATCH] splice: speedups and optimizations
[PATCH] pipe.c/fifo.c code cleanups
[PATCH] get rid of the PIPE_*() macros
[PATCH] splice: speedup __generic_file_splice_read
[PATCH] splice: add direct fd <-> fd splicing support
[PATCH] splice: add optional input and output offsets
[PATCH] introduce a "kernel-internal pipe object" abstraction
[PATCH] splice: be smarter about calling do_page_cache_readahead()
[PATCH] splice: optimize the splice buffer mapping
[PATCH] splice: cleanup __generic_file_splice_read()
[PATCH] splice: only call wake_up_interruptible() when we really have to
[PATCH] splice: potential !page dereference
[PATCH] splice: mark the io page as accessed
Keep unused openowners around for at least one lease period, to avoid the need
for as many open confirmations and to allow handing out more delegations.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It's very easy for the server to DOS itself by just giving out too many
delegations.
For now we just solve the problem with a dumb hard limit. Eventually we'll
want a smarter policy.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We should be shutting down rpciod for the callback channel when we shut down
the server.
Also note that we do rpciod_up() and create the callback client *before*
setting cb_set--the cb_set only determines whether the initial null was
succesful. So cb_set is not a reliable determiner of whether we need to clean
up, only cb_client is.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some obvious cleanup.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to make sure the laundromat work doesn't reschedule itself just when
we try to cancel it. Also, we shouldn't be waiting for it to finish running
while holding the state lock, as that's a potential deadlock.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix corruption on readdir encoding with 64k pages.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In v4 we grab an extra page just for the padding of returned data. The
formula that the rpc server uses to allocate pages for the response doesn't
take into account this extra page.
Instead of adjusting those formulae, we adopt the same solution as v2 and v3,
and put the "tail" data in the same page as the "head" data.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since nfsd_setuser() is already called from any operation that uses the
current filehandle (because it's called from fh_verify), there's no reason to
call it from putrootfh.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In addition to setting the processes filesystem id's, nfsd_setuser also
modifies the value of the rq_cred which stores the id's that originally came
from the rpc call, for example to reflect root squashing.
There's no real reason to do that--the only case where rqstp->rq_cred is
actually used later on is in the NFSv4 SETCLIENTID/SETCLIENTID_CONFIRM
operations, and there the results are the opposite of what we want--those two
operations don't deal with the filesystem at all, they only record the
credentials used with the rpc call for later reference (so that we may require
the same credentials be used on later operations), and the credentials
shouldn't vary just because there was or wasn't a previous operation in the
compound that referred to some export
This fixes a bug which caused mounts from Solaris clients to fail.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Export a directory that does not exist:
exportfs -orw,fsid=0,insecure,no_subtree_check client:/home/NFS4
Try to mount from client with nfs4. Mount hangs (I'm not sure why -
that's another issue).
While client is hung, back on server
mkdir /home/NFS4
The server panics in dput. I traced the problem back to svc_export_parse()
calling path_release() even though path_lookup() failed (it happens to fill in
the nameidata structure with a negative dentry - so the test after out:
succeeds).
After patching, an recreating the problem, the client mount still takes some
time before finally exiting with a message "couldn't read superblock".
Here is a simple patch to resolve this issue:
Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We should be using the length from the second vfs_getxattr, in case it
changed. (Note: there's still a small race here; we could end up returning
-ENOMEM if the length increased between the first and second call. I don't
know whether it's worth spending a lot of effort to fix that.)
This makes XFS ACLs usable on NFS exports, which they currently aren't, since
XFS appears to be returning a too-large value for vfs_getxattr() when it's
passed a NULL buffer. So there's probably an XFS bug here too, though since
getxattr with a NULL buffer is usually used to decide how much memory to
allocate, it may be a fairly harmless bug in most cases.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We're returning -1 in a few places in the NFSv4<->POSIX acl translation code
where we could return a reasonable error.
Also allows some minor simplification elsewhere.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
this fixes coverity id #3. Coverity detected dead code, since the == -1
comparison only returns 0 or 1 to error. Therefore the if ( error < 0 )
statement was always false. Seems that this was an if( error = nfs4... )
statement some time ago, which got broken during cleanup.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Marc Eshel <eshel@almaden.ibm.com>
Cc: Andy Adamson <andros@citi.umich.edu>
Cc: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the fl_lmops field to identify which locks are ours, instead of trying to
look them up in our private hash. This is safer and more efficient.
Earlier versions of this patch used a lock flag instead, but Trond pointed out
that adding a new flag for each lock manager wasn't going to scale well, and
suggested this approach instead; a separate patch converts lockd to using
fl_lmops in the same way.
In the NFSv4 case this looks like a bit of a hack, since the NFSv4 server
isn't currently actually defining a lock_manager_operations struct, so we end
up defining one *just* to serve as a cookie to identify our locks.
But it works, and we actually do expect to start using the
lock_manager_operations at some point anyway.
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
NFSd makes sure there is enough space to hold the maximum possible reply
before accepting a request. The units for this maximum is (4byte) words.
However in three places, particularly for read request, the number given is
a number of bytes.
This means too much space is reserved which is slightly wasteful.
This is the sort of patch that could uncover a deeper bug, and it is not
critical, so it would be best for it to spend a while in -mm before going
in to mainline.
(akpm: target 2.6.17-rc2, 2.6.16.3 (approx))
Discovered-by: "Eivind Sarto" <ivan@kasenna.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
- capitalize consistently
- end sentences in one way or another
- update comment text to match the implementation
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <axboe@suse.de>
