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path: root/fs/fuse/fuse_i.h
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2009-03-27constify dentry_operations: FUSEAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-11-26fuse: add fuse_conn->release()Tejun Heo
Add fuse_conn->release() so that fuse_conn can be embedded in other structures. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: separate out fuse_conn_init() from new_conn()Tejun Heo
Separate out fuse_conn_init() from new_conn() and while at it initialize fuse_conn->entry during conn initialization. This will be used by CUSE. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: add fuse_ prefix to several functionsTejun Heo
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 Heo
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: add file kernel handleTejun Heo
The file handle, fuse_file->fh, is opaque value supplied by userland FUSE server and uniqueness is not guaranteed. Add file kernel handle, fuse_file->kh, which is allocated by the kernel on file allocation and guaranteed to be unique. This will be used by poll to match notification to the respective file but can be used for other purposes where unique file handle is necessary. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-11-26fuse: style fixesMiklos Szeredi
Fix coding style errors reported by checkpatch and others. Uptdate copyright date to 2008. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-10-16fuse: add include protectorsTejun Heo
Add include protectors to include/linux/fuse.h and fs/fuse/fuse_i.h. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-07-25fuse: nfs export special lookupsMiklos Szeredi
Implement the get_parent export operation by sending a LOOKUP request with ".." as the name. Implement looking up an inode by node ID after it has been evicted from the cache. This is done by seding a LOOKUP request with "." as the name (for all file types, not just directories). The filesystem can set the FUSE_EXPORT_SUPPORT flag in the INIT reply, to indicate that it supports these special lookups. Thanks to John Muir for the original implementation of this feature. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Matthew Wilcox <matthew@wil.cx> Cc: David Teigland <teigland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25fuse: add export operationsMiklos Szeredi
Implement export_operations, to allow fuse filesystems to be exported to NFS. This feature has been in the out-of-tree fuse module, and is widely used and tested. It has not been originally merged into mainline, because doing the NFS export in userspace was thought to be a cleaner and more efficient way of doing it, than through the kernel. While that is true, it would also have involved a lot of duplicated effort at reimplementing NFS exporting (all the different versions of the protocol). This effort was unfortunately not undertaken by anyone, so we are left with doing it the easy but less efficient way. If this feature goes in, the out-of-tree fuse module can go away, which would have several advantages: - not having to maintain two versions - less confusion for users - no bugs due to kernel API changes Comment from hch: - Use the same fh_type values as XFS, since we use the same fh encoding. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13fuse: add flag to turn on big writesMiklos Szeredi
Prior to 2.6.26 fuse only supported single page write requests. In theory all fuse filesystem should be able support bigger than 4k writes, as there's nothing in the API to prevent it. Unfortunately there's a known case in NTFS-3G where big writes cause filesystem corruption. There could also be other filesystems, where the lack of testing with big write requests would result in bugs. To prevent such problems on a kernel upgrade, disable big writes by default, but let filesystems set a flag to turn it on. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Szabolcs Szakacsits <szaka@ntfs-3g.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30fuse: fix node ID typeMiklos Szeredi
Node ID is 64bit but it is passed as unsigned long to some functions. This breakage wasn't noticed, because libfuse uses unsigned long too. 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: update file size on short readMiklos Szeredi
If the READ request returned a short count, then either - cached size is incorrect - filesystem is buggy, as short reads are only allowed on EOF So assume that the size is wrong and refresh it, so that cached read() doesn't zero fill the missing chunk. 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 Szeredi
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>
2008-04-30mm: bdi: expose the BDI object in sysfs for FUSEMiklos Szeredi
Register FUSE's backing_dev_info under sysfs with the name "fuse-MAJOR:MINOR" Make the fuse control filesystem use s_dev instead of a fuse specific ID. This makes it easier to match directories under /sys/fs/fuse/connections/ with directories under /sys/class/bdi, and with actual mounts. 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 Szeredi
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>
2008-02-06fuse: save space in struct fuse_reqMiklos Szeredi
Move the fields 'dentry' and 'vfsmount' into the request specific union, since these are only used for the RELEASE request. 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>
2007-11-29fuse: pass open flags to read and writeMiklos Szeredi
Some open flags (O_APPEND, O_DIRECT) can be changed with fcntl(F_SETFL, ...) after open, but fuse currently only sends the flags to userspace in open. To make it possible to correcly handle changing flags, send the current value to userspace in each read and write. 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>
2007-11-29fuse: fix reading past EOFMiklos Szeredi
Currently reading a fuse file will stop at cached i_size and return EOF, even though the file might have grown since the attributes were last updated. So detect if trying to read past EOF, and refresh the attributes before continuing with the read. Thanks to mpb for the report. 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>
2007-10-18fuse: add support for mandatory lockingMiklos Szeredi
For mandatory locking the userspace filesystem needs to know the lock ownership for read, write and truncate operations. This patch adds the necessary fields to the protocol. 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>
2007-10-18fuse: add helper for asynchronous writesMiklos Szeredi
This patch adds a new helper function fuse_write_fill() which makes it possible to send WRITE requests asynchronously. A new flag for WRITE requests is also added which indicates that this a write from the page cache, and not a "normal" file write. This patch is in preparation for writable mmap support. 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>
2007-10-18fuse: add list of writable files to fuse_inodeMiklos Szeredi
Each WRITE request must carry a valid file descriptor. When a page is written back from a memory mapping, the file through which the page was dirtied is not available, so a new mechananism is needed to find a suitable file in ->writepage(s). A list of fuse_files is added to fuse_inode. The file is removed from the list in fuse_release(). This patch is in preparation for writable mmap support. 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>
2007-10-18fuse: add atomic open+truncate supportMiklos Szeredi
This patch allows fuse filesystems to implement open(..., O_TRUNC) as a single request, instead of separate truncate and open requests. 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>
2007-10-18fuse: fix race between getattr and writeMiklos Szeredi
Getattr and lookup operations can be running in parallel to attribute changing operations, such as write and setattr. This means, that if for example getattr was slower than a write, the cached size attribute could be set to a stale value. To prevent this race, introduce a per-filesystem attribute version counter. This counter is incremented whenever cached attributes are modified, and the incremented value stored in the inode. Before storing new attributes in the cache, getattr and lookup check, using the version number, whether the attributes have been modified during the request's lifetime. If so, the returned attributes are not cached, because they might be stale. Thanks to Jakub Bogusz for the bug report and test program. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Jakub Bogusz <jakub.bogusz@gemius.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18fuse: fix allowing operationsMiklos Szeredi
The following operation didn't check if sending the request was allowed: setattr listxattr statfs Some other operations don't explicitly do the check, but VFS calls ->permission() which checks this. 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 permission checking on sticky directoriesMiklos Szeredi
The VFS checks sticky bits on the parent directory even if the filesystem defines it's own ->permission(). In some situations (sshfs, mountlo, etc) the user does have permission to delete a file even if the attribute based checking would not allow it. So work around this by storing the permission bits separately and returning them in stat(), but cutting the permission bits off from inode->i_mode. This is slightly hackish, but it's probably not worth it to add new infrastructure in VFS and a slight performance penalty for all filesystems, just for the sake of fuse. [Jan Engelhardt] cosmetic fixes Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fuse: refresh stale attributes in fuse_permission()Miklos Szeredi
fuse_permission() didn't refresh inode attributes before using them, even if the validity has already expired. Thanks to Junjiro Okajima for spotting this. Also remove some old code to unconditionally refresh the attributes on the root inode. 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 Szeredi
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 Szeredi
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 Szeredi
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>
2007-04-08[PATCH] fuse: validate rootmode mount optionTimo Savola
If rootmode isn't valid, we hit the BUG() in fuse_init_inode. Now EINVAL is returned. Signed-off-by: Timo Savola <tsavola@movial.fi> 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>
2006-12-07[PATCH] fuse: add DESTROY operationMiklos Szeredi
Add a DESTROY operation for block device based filesystems. With the help of this operation, such a filesystem can flush dirty data to the device synchronously before the umount returns. This is needed in situations where the filesystem is assumed to be clean immediately after unmount (e.g. ejecting removable media). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] fuse: add bmap supportMiklos Szeredi
Add support for the BMAP operation for block device based filesystems. This is needed to support swap-files and lilo. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17[PATCH] fuse: fix handling of moved directoryMiklos Szeredi
Fuse considered it an error (EIO) if lookup returned a directory inode, to which a dentry already refered. This is because directory aliases are not allowed. But in a network filesystem this could happen legitimately, if a directory is moved on a remote client. This patch attempts to relax the restriction by trying to first evict the offending alias from the cache. If this fails, it still returns an error (EBUSY). A rarer situation is if an mkdir races with an indenpendent lookup, which finds the newly created directory already moved. In this situation the mkdir should return success, but that would be incorrect, since the dentry cannot be instantiated, so return EBUSY. Previously checking for a directory alias and instantiation of the dentry weren't done atomically in lookup/mkdir, hence two such calls racing with each other could create aliased directories. To prevent this introduce a new per-connection mutex: fuse_conn->inst_mutex, which is taken for instantiations with a directory inode. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] fuse: use jiffies_64Miklos Szeredi
It is entirely possible (though rare) that jiffies half-wraps around, while a dentry/inode remains in the cache. This could mean that the dentry/inode is not invalidated for another half wraparound-time. To get around this problem, use 64-bit jiffies. The only problem with this is that dentry->d_time is 32 bits on 32-bit archs. So use d_fsdata as the high 32 bits. This is an ugly hack, but far simpler, than having to allocate private data just for this purpose. Since 64-bit jiffies can be assumed never to wrap around, simple comparison can be used, and a zero time value can represent "invalid". 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: scramble lock owner IDMiklos Szeredi
VFS uses current->files pointer as lock owner ID, and it wouldn't be prudent to expose this value to userspace. So scramble it with XTEA using a per connection random key, known only to the kernel. Only one direction needs to be implemented, since the ID is never sent in the reverse direction. The XTEA algorithm is implemented inline since it's simple enough to do so, and this adds less complexity than if the crypto API were used. Thanks to Jesper Juhl for the idea. 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 request interruptionMiklos Szeredi
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 Szeredi
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 Szeredi
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 POSIX file locking supportMiklos Szeredi
This patch adds POSIX file locking support to the fuse interface. This implementation doesn't keep any locking state in kernel. Unlocking on close() is handled by the FLUSH message, which now contains the lock owner id. Mandatory locking is not supported. The filesystem may enfoce mandatory locking in userspace if needed. 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 Szeredi
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 Szeredi
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>
2006-04-26Revert "[fuse] fix deadlock between fuse_put_super() and request_end()"Miklos Szeredi
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] Fix accounting the number of waiting requestsMiklos Szeredi
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 Szeredi
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 Szeredi
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 Szeredi
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: use a per-mount spinlockMiklos Szeredi
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: add O_ASYNC support to FUSE deviceJeff Dike
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>
2006-03-28[PATCH] Make most file operations structs in fs/ constArjan van de Ven
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>