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* [fuse] fix deadlock between fuse_put_super() and request_end(), try #2Miklos Szeredi2006-04-26
| | | | | | | | | | | | | | | 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>
* Revert "[fuse] fix deadlock between fuse_put_super() and request_end()"Miklos Szeredi2006-04-26
| | | | | | | | | | | | | 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>
* [fuse] Don't init request twiceMiklos Szeredi2006-04-11
| | | | | | | 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>
* [fuse] Fix accounting the number of waiting requestsMiklos Szeredi2006-04-11
| | | | | | | Properly accounting the number of waiting requests was forgotten in "clean up request accounting" patch. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
* [fuse] fix deadlock between fuse_put_super() and request_end()Miklos Szeredi2006-04-11
| | | | | | | | | | | | | | | | | | | 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 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>
* [PATCH] fuse: account background requestsMiklos Szeredi2006-04-11
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] fuse: clean up request accountingMiklos Szeredi2006-04-11
| | | | | | | | | | | | | 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>
* [PATCH] fuse: consolidate device errorsMiklos Szeredi2006-04-11
| | | | | | | | | 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>
* [PATCH] fuse: use a per-mount spinlockMiklos Szeredi2006-04-11
| | | | | | | | | | | 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>
* [PATCH] fuse: simplify lockingMiklos Szeredi2006-04-11
| | | | | | | | | | | | | | | | | | | 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>
* [PATCH] fuse: add O_NONBLOCK support to FUSE deviceJeff Dike2006-04-11
| | | | | | | | | | 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>
* [PATCH] fuse: add O_ASYNC support to FUSE deviceJeff Dike2006-04-11
| | | | | | | | | | | | | | | | | | | 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>
* [PATCH] fuse: fix fuse_dev_poll() return valueMiklos Szeredi2006-04-11
| | | | | | | | | | | | 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>
* [PATCH] Make most file operations structs in fs/ constArjan van de Ven2006-03-28
| | | | | | | | | | | | | | This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: fix bug in aborted fuse_release_end()Miklos Szeredi2006-02-17
| | | | | | | | | | | | | | There's a rather theoretical case of the BUG triggering in fuse_reset_request(): - iget() fails because of OOM after a successful CREATE_OPEN request - during IO on the resulting RELEASE request the connection is aborted Fix and add warning to fuse_reset_request(). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: fix request_end() vs fuse_reset_request() raceMiklos Szeredi2006-02-05
| | | | | | | | | | | | The last fix for this function in fact opened up a much more often triggering race. It was uncommented tricky code, that was buggy. Add comment, make it less tricky and fix bug. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: move INIT handling to inode.cMiklos Szeredi2006-01-17
| | | | | | | | | 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>
* [PATCH] fuse: add asynchronous request supportMiklos Szeredi2006-01-17
| | | | | | | | | | | | 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>
* [PATCH] fuse: add connection abortingMiklos Szeredi2006-01-17
| | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] fuse: add number of waiting requests attributeMiklos Szeredi2006-01-17
| | | | | | | | | | 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>
* [PATCH] fuse: make fuse connection a kobjectMiklos Szeredi2006-01-17
| | | | | | | | | | | | | 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>
* [PATCH] fuse: extend semantics of connected flagMiklos Szeredi2006-01-17
| | | | | | | | | | | | | | 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>
* [PATCH] fuse: introduce list for requests under I/OMiklos Szeredi2006-01-17
| | | | | | | | | | 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>
* [PATCH] fuse: introduce unified request stateMiklos Szeredi2006-01-17
| | | | | | | | | | | 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>
* [PATCH] fuse: miscellaneous cleanupMiklos Szeredi2006-01-17
| | | | | | | | | | | | | | | - remove some unneeded assignments - use kzalloc instead of kmalloc + memset - simplify setting sb->s_fs_info - in fuse_send_init() use fuse_get_request() instead of do_get_request() helper Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: uninline some functionsMiklos Szeredi2006-01-17
| | | | | | | | 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>
* [PATCH] fuse: handle error INIT replyMiklos Szeredi2006-01-17
| | | | | | | | 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>
* [PATCH] fuse: fix request_end()Miklos Szeredi2006-01-17
| | | | | | | | | | | 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>
* [PATCH] fuse: fuse_copy_finish() order fixMiklos Szeredi2006-01-17
| | | | | | | | | | 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>
* [PATCH] fuse: make maximum write data configurableMiklos Szeredi2006-01-06
| | | | | | | | | | | | | | | Make the maximum size of write data configurable by the filesystem. The previous fixed 4096 limit only worked on architectures where the page size is less or equal to this. This change make writing work on other architectures too, and also lets the filesystem receive bigger write requests in direct_io mode. Normal writes which go through the page cache are still limited to a page sized chunk per request. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: clean up request size limit checkingMiklos Szeredi2006-01-06
| | | | | | | | | | | | | | | | | | | | | Change the way a too large request is handled. Until now in this case the device read returned -EINVAL and the operation returned -EIO. Make it more flexibible by not returning -EINVAL from the read, but restarting it instead. Also remove the fixed limit on setxattr data and let the filesystem provide as large a read buffer as it needs to handle the extended attribute data. The symbolic link length is already checked by VFS to be less than PATH_MAX, so the extra check against FUSE_SYMLINK_MAX is not needed. The check in fuse_create_open() against FUSE_NAME_MAX is not needed, since the dentry has already been looked up, and hence the name already checked. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: bump interface versionMiklos Szeredi2006-01-06
| | | | | | | | | | | Change interface version to 7.4. Following changes will need backward compatibility support, so store the minor version returned by userspace. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] FUSE: atomic create+openMiklos Szeredi2005-11-07
| | | | | | | | | | This patch adds an atomic create+open operation. This does not yet work if the file type changes between lookup and create+open, but solves the permission checking problems for the separte create and open methods. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: spelling fixesMiklos Szeredi2005-10-30
| | | | | | | | | Correct some typos and inconsistent use of "initialise" vs "initialize" in comments. Reported by Ioannis Barkas. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] FUSE: don't allow restarting of system callsMiklos Szeredi2005-09-09
| | | | | | | | | | | | | | | | | | | | | This patch removes ability to interrupt and restart operations while there hasn't been any side-effect. The reason: applications. There are some apps it seems that generate signals at a fast rate. This means, that if the operation cannot make enough progress between two signals, it will be restarted for ever. This bug actually manifested itself with 'krusader' trying to open a file for writing under sshfs. Thanks to Eduard Czimbalmos for the report. The problem can be solved just by making open() uninterruptible, because in this case it was the truncate operation that slowed down the progress. But it's better to solve this by simply not allowing interrupts at all (except SIGKILL), because applications don't expect file operations to be interruptible anyway. As an added bonus the code is simplified somewhat. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fuse: transfer readdir data through deviceMiklos Szeredi2005-09-09
| | | | | | | | | | | | | | | | | This patch removes a long lasting "hack" in FUSE, which used a separate channel (a file descriptor refering to a disk-file) to transfer directory contents from userspace to the kernel. The patch adds three new operations (OPENDIR, READDIR, RELEASEDIR), which have semantics and implementation exactly maching the respective file operations (OPEN, READ, RELEASE). This simplifies the directory reading code. Also disk space is not necessary, which can be important in embedded systems. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] FUSE - mount optionsMiklos Szeredi2005-09-09
| | | | | | | | | | | | | | | This patch adds miscellaneous mount options to the FUSE filesystem. The following mount options are added: o default_permissions: check permissions with generic_permission() o allow_other: allow other users to access files o allow_root: allow root to access files o kernel_cache: don't invalidate page cache on open Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] FUSE - read-only operationsMiklos Szeredi2005-09-09
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the read-only filesystem operations of FUSE. This contains the following files: o dir.c - directory, symlink and file-inode operations The following operations are added: o lookup o getattr o readlink o follow_link o directory open o readdir o directory release o permission o dentry revalidate o statfs Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] FUSE - device functionsMiklos Szeredi2005-09-09
This adds the FUSE device handling functions. This contains the following files: o dev.c - fuse device operations (read, write, release, poll) - registers misc device - support for sending requests to userspace Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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