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* fuse: allow batching of FORGET requestsMiklos Szeredi2010-12-071-11/+81
| | | | | | | | | | | | | | | Terje Malmedal reports that a fuse filesystem with 32 million inodes on a machine with lots of memory can take up to 30 minutes to process FORGET requests when all those inodes are evicted from the icache. To solve this, create a BATCH_FORGET request that allows up to about 8000 FORGET requests to be sent in a single message. This request is only sent if userspace supports interface version 7.16 or later, otherwise fall back to sending individual FORGET messages. Reported-by: Terje Malmedal <terje.malmedal@usit.uio.no> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: separate queue for FORGET requestsMiklos Szeredi2010-12-071-9/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | Terje Malmedal reports that a fuse filesystem with 32 million inodes on a machine with lots of memory can go unresponsive for up to 30 minutes when all those inodes are evicted from the icache. The reason is that FORGET messages, sent when the inode is evicted, are queued up together with regular filesystem requests, and while the huge queue of FORGET messages are processed no other filesystem operation can proceed. Since a full fuse request structure is allocated for each inode, these take up quite a bit of memory as well. To solve these issues, create a slim 'fuse_forget_link' structure containing just the minimum of information required to send the FORGET request and chain these on a separate queue. When userspace is asking for a request make sure that FORGET and non-FORGET requests are selected fairly: for each 8 non-FORGET allow 16 FORGET requests. This will make sure FORGETs do not pile up, yet other requests are also allowed to proceed while the queued FORGETs are processed. Reported-by: Terje Malmedal <terje.malmedal@usit.uio.no> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: use release_pages()Miklos Szeredi2010-10-281-6/+1Star
| | | | | | | | | | | | Replace iterated page_cache_release() with release_pages(), which is faster and shorter. Needs release_pages() to be exported to modules. Suggested-by: Andrew Morton <akpm@linux-foundation.org> 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>
* fuse: use clear_highpage() and KM_USER0 instead of KM_USER1Miklos Szeredi2010-10-271-7/+5Star
| | | | | | | | | | | Commit 7909b1c640 ("fuse: don't use atomic kmap") removed KM_USER0 usage from fuse/dev.c. Switch KM_USER1 uses to KM_USER0 for clarity. Also replace open coded clear_highpage(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* use clear_page()/copy_page() in favor of memset()/memcpy() on whole pagesJan Beulich2010-10-271-1/+1
| | | | | | | | | | | After all that's what they are intended for. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fuse: Initialize total_len in fuse_retrieve()Geert Uytterhoeven2010-10-041-1/+1
| | | | | | | | | | fs/fuse/dev.c:1357: warning: ‘total_len’ may be used uninitialized in this function Initialize total_len to zero, else its value will be undefined. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: fix lock annotationsMiklos Szeredi2010-09-071-12/+14
| | | | | | | | Sparse doesn't understand lock annotations of the form __releases(&foo->lock). Change them to __releases(foo->lock). Same for __acquires(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: flush background queue on connection closeMiklos Szeredi2010-09-071-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | David Bartly reported that fuse can hang in fuse_get_req_nofail() when the connection to the filesystem server is no longer active. If bg_queue is not empty then flush_bg_queue() called from request_end() can put more requests on to the pending queue. If this happens while ending requests on the processing queue then those background requests will be queued to the pending list and never ended. Another problem is that fuse_dev_release() didn't wake up processes sleeping on blocked_waitq. Solve this by: a) flushing the background queue before calling end_requests() on the pending and processing queues b) setting blocked = 0 and waking up processes waiting on blocked_waitq() Thanks to David for an excellent bug report. Reported-by: David Bartley <andareed@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org
* fuse: add retrieve requestMiklos Szeredi2010-07-121-1/+130
| | | | | | | | | | | | | | | | Userspace filesystem can request data to be retrieved from the inode's mapping. This request is synchronous and the retrieved data is queued as a new request. If the write to the fuse device returns an error then the retrieve request was not completed and a reply will not be sent. Only present pages are returned in the retrieve reply. Retrieving stops when it finds a non-present page and only data prior to that is returned. This request doesn't change the dirty state of pages. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: add store requestMiklos Szeredi2010-07-121-0/+88
| | | | | | | | | | | | | | Userspace filesystem can request data to be stored in the inode's mapping. This request is synchronous and has no reply. If the write to the fuse device returns an error then the store request was not fully completed (but may have updated some pages). If the stored data overflows the current file size, then the size is extended, similarly to a write(2) on the filesystem. Pages which have been completely stored are marked uptodate. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: don't use atomic kmapMiklos Szeredi2010-07-121-5/+5
| | | | | | | | | | | | | | | | Don't use atomic kmap for mapping userspace buffers in device read/write/splice. This is necessary because the next patch (adding store notify) requires that caller of fuse_copy_page() may sleep between invocations. The simplest way to ensure this is to change the atomic kmaps to non-atomic ones. Thankfully architectures where kmap() is not a no-op are going out of fashion, so we can ignore the (probably negligible) performance impact of this change. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* Merge branch 'for-linus' of ↵Linus Torvalds2010-05-301-66/+461
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: mm: export generic_pipe_buf_*() to modules fuse: support splice() reading from fuse device fuse: allow splice to move pages mm: export remove_from_page_cache() to modules mm: export lru_cache_add_*() to modules fuse: support splice() writing to fuse device fuse: get page reference for readpages fuse: use get_user_pages_fast() fuse: remove unneeded variable
| * fuse: support splice() reading from fuse deviceMiklos Szeredi2010-05-251-41/+187
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow userspace filesystem implementation to use splice() to read from the fuse device. The userspace filesystem can now transfer data coming from a WRITE request to an arbitrary file descriptor (regular file, block device or socket) without having to go through a userspace buffer. The semantics of using splice() to read messages are: 1) with a single splice() call move the whole message from the fuse device to a temporary pipe 2) read the header from the pipe and determine the message type 3a) if message is a WRITE then splice data from pipe to destination 3b) else read rest of message to userspace buffer Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: allow splice to move pagesMiklos Szeredi2010-05-251-6/+145
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When splicing buffers to the fuse device with SPLICE_F_MOVE, try to move pages from the pipe buffer into the page cache. This allows populating the fuse filesystem's cache without ever touching the page contents, i.e. zero copy read capability. The following steps are performed when trying to move a page into the page cache: - buf->ops->confirm() to make sure the new page is uptodate - buf->ops->steal() to try to remove the new page from it's previous place - remove_from_page_cache() on the old page - add_to_page_cache_locked() on the new page If any of the above steps fail (non fatally) then the code falls back to copying the page. In particular ->steal() will fail if there are external references (other than the page cache and the pipe buffer) to the page. Also since the remove_from_page_cache() + add_to_page_cache_locked() are non-atomic it is possible that the page cache is repopulated in between the two and add_to_page_cache_locked() will fail. This could be fixed by creating a new atomic replace_page_cache_page() function. fuse_readpages_end() needed to be reworked so it works even if page->mapping is NULL for some or all pages which can happen if the add_to_page_cache_locked() failed. A number of sanity checks were added to make sure the stolen pages don't have weird flags set, etc... These could be moved into generic splice/steal code. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: support splice() writing to fuse deviceMiklos Szeredi2010-05-251-31/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow userspace filesystem implementation to use splice() to write to the fuse device. The semantics of using splice() are: 1) buffer the message header and data in a temporary pipe 2) with a *single* splice() call move the message from the temporary pipe to the fuse device The READ reply message has the most interesting use for this, since now the data from an arbitrary file descriptor (which could be a regular file, a block device or a socket) can be tranferred into the fuse device without having to go through a userspace buffer. It will also allow zero copy moving of pages. One caveat is that the protocol on the fuse device requires the length of the whole message to be written into the header. But the length of the data transferred into the temporary pipe may not be known in advance. The current library implementation works around this by using vmplice to write the header and modifying the header after splicing the data into the pipe (error handling omitted): struct fuse_out_header out; iov.iov_base = &out; iov.iov_len = sizeof(struct fuse_out_header); vmsplice(pip[1], &iov, 1, 0); len = splice(input_fd, input_offset, pip[1], NULL, len, 0); /* retrospectively modify the header: */ out.len = len + sizeof(struct fuse_out_header); splice(pip[0], NULL, fuse_chan_fd(req->ch), NULL, out.len, flags); This works since vmsplice only saves a pointer to the data, it does not copy the data itself. Since pipes are currently limited to 16 pages and messages need to be spliced atomically, the length of the data is limited to 15 pages (or 60kB for 4k pages). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| * fuse: use get_user_pages_fast()Miklos Szeredi2010-05-251-4/+1Star
| | | | | | | | | | | | | | Replace uses of get_user_pages() with get_user_pages_fast(). It looks nicer and should be faster in most cases. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* | driver core: add devname module aliases to allow module on-demand auto-loadingKay Sievers2010-05-261-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds: alias: devname:<name> to some common kernel modules, which will allow the on-demand loading of the kernel module when the device node is accessed. Ideally all these modules would be compiled-in, but distros seems too much in love with their modularization that we need to cover the common cases with this new facility. It will allow us to remove a bunch of pretty useless init scripts and modprobes from init scripts. The static device node aliases will be carried in the module itself. The program depmod will extract this information to a file in the module directory: $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname # Device nodes to trigger on-demand module loading. microcode cpu/microcode c10:184 fuse fuse c10:229 ppp_generic ppp c108:0 tun net/tun c10:200 dm_mod mapper/control c10:235 Udev will pick up the depmod created file on startup and create all the static device nodes which the kernel modules specify, so that these modules get automatically loaded when the device node is accessed: $ /sbin/udevd --debug ... static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184 static_dev_create_from_modules: mknod '/dev/fuse' c10:229 static_dev_create_from_modules: mknod '/dev/ppp' c108:0 static_dev_create_from_modules: mknod '/dev/net/tun' c10:200 static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235 udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666 udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666 A few device nodes are switched to statically allocated numbers, to allow the static nodes to work. This might also useful for systems which still run a plain static /dev, which is completely unsafe to use with any dynamic minor numbers. Note: The devname aliases must be limited to the *common* and *single*instance* device nodes, like the misc devices, and never be used for conceptually limited systems like the loop devices, which should rather get fixed properly and get a control node for losetup to talk to, instead of creating a random number of device nodes in advance, regardless if they are ever used. This facility is to hide the mess distros are creating with too modualized kernels, and just to hide that these modules are not compiled-in, and not to paper-over broken concepts. Thanks! :) Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Ian Kent <raven@themaw.net> Signed-Off-By: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* fuse: fix large stack useFang Wenqi2010-02-051-2/+9
| | | | | | | | | | | | gcc 4.4 warns about: fs/fuse/dev.c: In function ‘fuse_notify_inval_entry’: fs/fuse/dev.c:925: warning: the frame size of 1060 bytes is larger than 1024 bytes The problem is we declare two structures and a large array on the stack, I move the array alway from the stack and allocate memory for it dynamically. Signed-off-by: Fang Wenqi <antonf@turbolinux.com.cn> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* fuse: cleanup in fuse_notify_inval_...()Miklos Szeredi2010-02-051-13/+6Star
| | | | | | | Small cleanup in fuse_notify_inval_inode() and fuse_notify_inval_entry(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-09-181-5/+5
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * '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
| * fuse: make the number of max background requests and congestion threshold ↵Csaba Henk2009-07-071-5/+5
| | | | | | | | | | | | | | | | | | | | tunable 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>
* | Revert "fuse: Fix build error" as unnecessaryLinus Torvalds2009-07-111-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | 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>
* | fuse: Fix build errorLarry Finger2009-07-111-0/+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>
* | Fix congestion_wait() sync/async vs read/write confusionJens Axboe2009-07-101-4/+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>
* fuse: invalidation reverse callsJohn Muir2009-06-301-0/+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>
* fuse: fix return value of fuse_dev_write()Csaba Henk2009-06-301-1/+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
* fuse: export symbols to be used by CUSETejun Heo2009-04-281-1/+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>
* fuse: update fuse_conn_init() and separate out fuse_conn_kill()Tejun Heo2009-04-281-2/+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>
* fuse: fix poll notifyMiklos Szeredi2009-01-261-4/+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>
* fuse: destroy bdi on umountMiklos Szeredi2009-01-261-1/+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
* Merge branch 'for-linus' of ↵Linus Torvalds2009-01-071-30/+83
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * '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
| * fuse: clean up annotations of fc->lockHarvey Harrison2008-12-021-5/+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>
| * fuse: add fuse_ prefix to several functionsTejun Heo2008-11-261-11/+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>
| * fuse: implement poll supportTejun Heo2008-11-261-0/+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>
| * fuse: implement unsolicited notificationTejun Heo2008-11-261-2/+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>
| * fuse: don't let fuse_req->end() put the base referenceTejun Heo2008-11-261-3/+2Star
| | | | | | | | | | | | | | | | | | 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>
| * fuse: style fixesMiklos Szeredi2008-11-261-9/+13
| | | | | | | | | | | | | | Fix coding style errors reported by checkpatch and others. Uptdate copyright date to 2008. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* | CRED: Wrap task credential accesses in the FUSE filesystemDavid Howells2008-11-141-2/+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>
* saner FASYNC handling on file closeAl Viro2008-11-011-1/+0Star
| | | | | | | | | | | | | | 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>
* fuse: fix sparse warningsMiklos Szeredi2008-04-301-1/+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>
* fuse: support writable mmapMiklos Szeredi2008-04-301-0/+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>
* fuse: limit queued background requestsMiklos Szeredi2008-02-061-46/+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>
* fuse: no ENOENT from fuse device readMiklos Szeredi2007-10-171-4/+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>
* fuse: no abort on interruptMiklos Szeredi2007-10-171-19/+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>
* fuse: cleanup in releaseMiklos Szeredi2007-10-171-2/+0Star
| | | | | | | | | 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>
* fuse: add reference counting to fuse_fileMiklos Szeredi2007-10-171-2/+0Star
| | | | | | | | | | | | | | | | 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>
* fuse: fix reserved request wake upMiklos Szeredi2007-10-171-2/+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>
* fuse: update backing_dev_info congestion stateMiklos Szeredi2007-10-171-0/+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>
* mm: Remove slab destructors from kmem_cache_create().Paul Mundt2007-07-201-1/+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>
* [PATCH] slab: remove kmem_cache_tChristoph Lameter2006-12-071-1/+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>
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