aboutsummaryrefslogtreecommitdiffstats
path: root/fs/fuse/dev.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2009-09-18Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuseLinus Torvalds1-5/+5
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: add fusectl interface to max_background fuse: limit user-specified values of max background requests fuse: use drop_nlink() instead of direct nlink manipulation fuse: document protocol version negotiation fuse: make the number of max background requests and congestion threshold tunable
2009-07-11Revert "fuse: Fix build error" as unnecessaryLinus Torvalds1-1/+0
This reverts commit 097041e576ee3a50d92dd643ee8ca65bf6a62e21. Trond had a better fix, which is the parent of this one ("Fix compile error due to congestion_wait() changes") Requested-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10fuse: Fix build errorLarry Finger1-0/+1
When building v2.6.31-rc2-344-g69ca06c, the following build errors are found due to missing includes: CC [M] fs/fuse/dev.o fs/fuse/dev.c: In function ‘request_end’: fs/fuse/dev.c:289: error: ‘BLK_RW_SYNC’ undeclared (first use in this function) ... fs/nfs/write.c: In function ‘nfs_set_page_writeback’: fs/nfs/write.c:207: error: ‘BLK_RW_ASYNC’ undeclared (first use in this function) Signed-off-by: Larry Finger@lwfinger.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10Fix congestion_wait() sync/async vs read/write confusionJens Axboe1-4/+4
Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke the bdi congestion wait queue logic, causing us to wait on congestion for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-07fuse: make the number of max background requests and congestion threshold tunableCsaba Henk1-5/+5
The practical values for these limits depend on the design of the filesystem server so let userspace set them at initialization time. Signed-off-by: Csaba Henk <csaba@gluster.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2009-06-30fuse: invalidation reverse callsJohn Muir1-0/+81
Add notification messages that allow the filesystem to invalidate VFS caches. Two notifications are added: 1) inode invalidation - invalidate cached attributes - invalidate a range of pages in the page cache (this is optional) 2) dentry invalidation - try to invalidate a subtree in the dentry cache Care must be taken while accessing the 'struct super_block' for the mount, as it can go away while an invalidation is in progress. To prevent this, introduce a rw-semaphore, that is taken for read during the invalidation and taken for write in the ->kill_sb callback. Cc: Csaba Henk <csaba@gluster.com> Cc: Anand Avati <avati@zresearch.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2009-06-30fuse: fix return value of fuse_dev_write()Csaba Henk1-1/+1
On 64 bit systems -- where sizeof(ssize_t) > sizeof(int) -- the following test exposes a bug due to a non-careful return of an int or unsigned value: implement a FUSE filesystem which sends an unsolicited notification to the kernel with invalid opcode. The respective write to /dev/fuse will return (1 << 32) - EINVAL with errno == 0 instead of -1 with errno == EINVAL. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
2009-04-28fuse: export symbols to be used by CUSETejun Heo1-1/+9
Export the following symbols for CUSE. fuse_conn_put() fuse_conn_get() fuse_conn_kill() fuse_send_init() fuse_do_open() fuse_sync_release() fuse_direct_io() fuse_do_ioctl() fuse_file_poll() fuse_request_alloc() fuse_get_req() fuse_put_request() fuse_request_send() fuse_abort_conn() fuse_dev_release() fuse_dev_operations Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2009-04-28fuse: update fuse_conn_init() and separate out fuse_conn_kill()Tejun Heo1-2/+3
Update fuse_conn_init() such that it doesn't take @sb and move bdi registration into a separate function. Also separate out fuse_conn_kill() from fuse_put_super(). These will be used to implement cuse. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2009-01-26fuse: fix poll notifyMiklos Szeredi1-4/+9
Move fuse_copy_finish() to before calling fuse_notify_poll_wakeup(). This is not a big issue because fuse_notify_poll_wakeup() should be atomic, but it's cleaner this way, and later uses of notification will need to be able to finish the copying before performing some actions. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2009-01-26fuse: destroy bdi on umountMiklos Szeredi1-1/+2
If a fuse filesystem is unmounted but the device file descriptor remains open and a new mount reuses the old device number, then the mount fails with EEXIST and the following warning is printed in the kernel log: WARNING: at fs/sysfs/dir.c:462 sysfs_add_one+0x35/0x3d() sysfs: duplicate filename '0:15' can not be created The cause is that the bdi belonging to the fuse filesystem was destoryed only after the device file was released. Fix this by calling bdi_destroy() from fuse_put_super() instead. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
2009-01-06Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuseLinus Torvalds1-30/+83
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: clean up annotations of fc->lock fuse: fix sparse warning in ioctl fuse: update interface version fuse: add fuse_conn->release() fuse: separate out fuse_conn_init() from new_conn() fuse: add fuse_ prefix to several functions fuse: implement poll support fuse: implement unsolicited notification fuse: add file kernel handle fuse: implement ioctl support fuse: don't let fuse_req->end() put the base reference fuse: move FUSE_MINOR to miscdevice.h fuse: style fixes
2008-12-02fuse: clean up annotations of fc->lockHarvey Harrison1-5/+12
Makes the existing annotations match the more common one per line style and adds a few missing annotations. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: add fuse_ prefix to several functionsTejun Heo1-11/+12
Add fuse_ prefix to request_send*() and get_root_inode() as some of those functions will be exported for CUSE. With or without CUSE export, having the function names scoped is a good idea for debuggability. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: implement poll supportTejun Heo1-0/+19
Implement poll support. Polled files are indexed using kh in a RB tree rooted at fuse_conn->polled_files. Client should send FUSE_NOTIFY_POLL notification once after processing FUSE_POLL which has FUSE_POLL_SCHEDULE_NOTIFY set. Sending notification unconditionally after the latest poll or everytime file content might have changed is inefficient but won't cause malfunction. fuse_file_poll() can sleep and requires patches from the following thread which allows f_op->poll() to sleep. http://thread.gmane.org/gmane.linux.kernel/726176 Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: implement unsolicited notificationTejun Heo1-2/+25
Clients always used to write only in response to read requests. To implement poll efficiently, clients should be able to issue unsolicited notifications. This patch implements basic notification support. Zero fuse_out_header.unique is now accepted and considered unsolicited notification and the error field contains notification code. This patch doesn't implement any actual notification. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: don't let fuse_req->end() put the base referenceTejun Heo1-3/+2
fuse_req->end() was supposed to be put the base reference but there's no reason why it should. It only makes things more complex. Move it out of ->end() and make it the responsibility of request_end(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: style fixesMiklos Szeredi1-9/+13
Fix coding style errors reported by checkpatch and others. Uptdate copyright date to 2008. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-14CRED: Wrap task credential accesses in the FUSE filesystemDavid Howells1-2/+2
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: fuse-devel@lists.sourceforge.net Signed-off-by: James Morris <jmorris@namei.org>
2008-11-01saner FASYNC handling on file closeAl Viro1-1/+0
As it is, all instances of ->release() for files that have ->fasync() need to remember to evict file from fasync lists; forgetting that creates a hole and we actually have a bunch that *does* forget. So let's keep our lives simple - let __fput() check FASYNC in file->f_flags and call ->fasync() there if it's been set. And lose that crap in ->release() instances - leaving it there is still valid, but we don't have to bother anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30fuse: fix sparse warningsMiklos Szeredi1-1/+3
fs/fuse/dev.c:306:2: warning: context imbalance in 'wait_answer_interruptible' - unexpected unlock fs/fuse/dev.c:361:2: warning: context imbalance in 'request_wait_answer' - unexpected unlock fs/fuse/dev.c:1002:4: warning: context imbalance in 'end_io_requests' - unexpected unlock Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30fuse: support writable mmapMiklos Szeredi1-0/+19
Quoting Linus (3 years ago, FUSE inclusion discussions): "User-space filesystems are hard to get right. I'd claim that they are almost impossible, unless you limit them somehow (shared writable mappings are the nastiest part - if you don't have those, you can reasonably limit your problems by limiting the number of dirty pages you accept through normal "write()" calls)." Instead of attempting the impossible, I've just waited for the dirty page accounting infrastructure to materialize (thanks to Peter Zijlstra and others). This nicely solved the biggest problem: limiting the number of pages used for write caching. Some small details remained, however, which this largish patch attempts to address. It provides a page writeback implementation for fuse, which is completely safe against VM related deadlocks. Performance may not be very good for certain usage patterns, but generally it should be acceptable. It has been tested extensively with fsx-linux and bash-shared-mapping. Fuse page writeback design -------------------------- fuse_writepage() allocates a new temporary page with GFP_NOFS|__GFP_HIGHMEM. It copies the contents of the original page, and queues a WRITE request to the userspace filesystem using this temp page. The writeback is finished instantly from the MM's point of view: the page is removed from the radix trees, and the PageDirty and PageWriteback flags are cleared. For the duration of the actual write, the NR_WRITEBACK_TEMP counter is incremented. The per-bdi writeback count is not decremented until the actual write completes. On dirtying the page, fuse waits for a previous write to finish before proceeding. This makes sure, there can only be one temporary page used at a time for one cached page. This approach is wasteful in both memory and CPU bandwidth, so why is this complication needed? The basic problem is that there can be no guarantee about the time in which the userspace filesystem will complete a write. It may be buggy or even malicious, and fail to complete WRITE requests. We don't want unrelated parts of the system to grind to a halt in such cases. Also a filesystem may need additional resources (particularly memory) to complete a WRITE request. There's a great danger of a deadlock if that allocation may wait for the writepage to finish. Currently there are several cases where the kernel can block on page writeback: - allocation order is larger than PAGE_ALLOC_COSTLY_ORDER - page migration - throttle_vm_writeout (through NR_WRITEBACK) - sync(2) Of course in some cases (fsync, msync) we explicitly want to allow blocking. So for these cases new code has to be added to fuse, since the VM is not tracking writeback pages for us any more. As an extra safetly measure, the maximum dirty ratio allocated to a single fuse filesystem is set to 1% by default. This way one (or several) buggy or malicious fuse filesystems cannot slow down the rest of the system by hogging dirty memory. With appropriate privileges, this limit can be raised through '/sys/class/bdi/<bdi>/max_ratio'. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06fuse: limit queued background requestsMiklos Szeredi1-46/+67
Libfuse basically creates a new thread for each new request. This is fine for synchronous requests, which are naturally limited. However background requests (especially writepage) can cause a thread creation storm. To avoid this, limit the number of background requests available to userspace. This is done by introducing another queue for background requests, and a counter for the number of "active" requests, which are currently available for userspace. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: no ENOENT from fuse device readMiklos Szeredi1-4/+5
Don't return -ENOENT for a read() on the fuse device when the request was aborted. Instead return -ENODEV, meaning the filesystem has been force-umounted or aborted. Previously ENOENT meant that the request was interrupted, but now the 'aborted' flag is not set in case of interrupts. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: no abort on interruptMiklos Szeredi1-19/+24
Don't set 'aborted' flag on a request if it's interrupted. We have to wait for the answer anyway, and this would only a very little time while copying the reply. This means, that write() on the fuse device will not return -ENOENT during normal operation, only if the filesystem is aborted by a forced umount or through the fusectl interface. This could simplify userspace code somewhat when backward compatibility with earlier kernel versions is not required. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: cleanup in releaseMiklos Szeredi1-2/+0
Move dput/mntput pair from request_end() to fuse_release_end(), because there's no other place they are used. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: add reference counting to fuse_fileMiklos Szeredi1-2/+0
Make lifetime of 'struct fuse_file' independent from 'struct file' by adding a reference counter and destructor. This will enable asynchronous page writeback, where it cannot be guaranteed, that the file is not released while a request with this file handle is being served. The actual RELEASE request is only sent when there are no more references to the fuse_file. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: fix reserved request wake upMiklos Szeredi1-2/+2
Use wake_up_all instead of wake_up in put_reserved_req(), otherwise it is possible that the right task is not woken up. Also create a separate reserved_req_waitq in addition to the blocked_waitq, since they fulfill totally separate functions. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: update backing_dev_info congestion stateMiklos Szeredi1-0/+8
Set the read and write congestion state if the request queue is close to blocking, and clear it when it's not. This prevents unnecessary blocking in readahead and (when writable mmaps are allowed) writeback. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20mm: Remove slab destructors from kmem_cache_create().Paul Mundt1-1/+1
Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-12-07[PATCH] slab: remove kmem_cache_tChristoph Lameter1-1/+1
Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] slab: remove SLAB_KERNELChristoph Lameter1-1/+1
SLAB_KERNEL is an alias of GFP_KERNEL. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] Remove readv/writev methods and use aio_read/aio_write insteadBadari Pulavarty1-27/+10
This patch removes readv() and writev() methods and replaces them with aio_read()/aio_write() methods. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] fuse: add lock annotations to request_end and fuse_read_interruptJosh Triplett1-0/+2
request_end and fuse_read_interrupt release fc->lock. Add lock annotations to these two functions so that sparse can check callers for lock pairing, and so that sparse will not complain about these functions since they intentionally use locks in this manner. Signed-off-by: Josh Triplett <josh@freedesktop.org> Acked-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] fuse: add request interruptionMiklos Szeredi1-27/+135
Add synchronous request interruption. This is needed for file locking operations which have to be interruptible. However filesystem may implement interruptibility of other operations (e.g. like NFS 'intr' mount option). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] fuse: rename the interrupted flagMiklos Szeredi1-20/+19
Rename the 'interrupted' flag to 'aborted', since it indicates exactly that, and next patch will introduce an 'interrupted' flag for a Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] fuse: ensure FLUSH reaches userspaceMiklos Szeredi1-4/+84
All POSIX locks owned by the current task are removed on close(). If the FLUSH request resulting initiated by close() fails to reach userspace, there might be locks remaining, which cannot be removed. The only reason it could fail, is if allocating the request fails. In this case use the request reserved for RELEASE, or if that is currently used by another FLUSH, wait for it to become available. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] fuse: add control filesystemMiklos Szeredi1-1/+1
Add a control filesystem to fuse, replacing the attributes currently exported through sysfs. An empty directory '/sys/fs/fuse/connections' is still created in sysfs, and mounting the control filesystem here provides backward compatibility. Advantages of the control filesystem over the previous solution: - allows the object directory and the attributes to be owned by the filesystem owner, hence letting unpriviled users abort the filesystem connection - does not suffer from module unload race [akpm@osdl.org: fix this fs for recent dhowells depredations] [akpm@osdl.org: fix 64-bit printk warnings] Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] fuse: no backgrounding on interruptMiklos Szeredi1-113/+44
Don't put requests into the background when a fatal interrupt occurs while the request is in userspace. This removes a major wart from the implementation. Backgrounding of requests was introduced to allow breaking of deadlocks. However now the same can be achieved by aborting the filesystem through the 'abort' sysfs attribute. This is a change in the interface, but should not cause problems, since these kinds of deadlocks never happen during normal operation. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26[fuse] fix deadlock between fuse_put_super() and request_end(), try #2Miklos Szeredi1-2/+11
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 solution is to move the fput() outside the region protected by sbput_sem. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-26Revert "[fuse] fix deadlock between fuse_put_super() and request_end()"Miklos Szeredi1-16/+12
This reverts 73ce8355c243a434524a34c05cc417dd0467996e commit. It was wrong, because it didn't take into account the requirement, that iput() for background requests must be performed synchronously with ->put_super(), otherwise active inodes may remain after unmount. The right solution is to keep the sbput_sem and perform iput() within the locked region, but move fput() outside sbput_sem. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11[fuse] Don't init request twiceMiklos Szeredi1-1/+0
Request is already initialized in fuse_request_alloc() so no need to do it again in fuse_get_req(). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11[fuse] Fix accounting the number of waiting requestsMiklos Szeredi1-6/+19
Properly accounting the number of waiting requests was forgotten in "clean up request accounting" patch. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2006-04-11[fuse] fix deadlock between fuse_put_super() and request_end()Miklos Szeredi1-12/+16
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>
2006-04-11[PATCH] fuse: account background requestsMiklos Szeredi1-4/+20
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>
2006-04-11[PATCH] fuse: clean up request accountingMiklos Szeredi1-64/+9
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>
2006-04-11[PATCH] fuse: consolidate device errorsMiklos Szeredi1-2/+2
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>
2006-04-11[PATCH] fuse: use a per-mount spinlockMiklos Szeredi1-60/+62
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>
2006-04-11[PATCH] fuse: simplify lockingMiklos Szeredi1-20/+11
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>
2006-04-11[PATCH] fuse: add O_NONBLOCK support to FUSE deviceJeff Dike1-0/+6
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>