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2011-03-01fs/block_dev.c: fix new kernel-doc warningRandy Dunlap
Fix new kernel-doc warning in fs/block_dev.c: Warning(fs/block_dev.c:937): No description found for parameter 'kill_dirty' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds
* 'for-linus' of git://neil.brown.name/md: md: Fix - again - partition detection when array becomes active Fix over-zealous flush_disk when changing device size. md: avoid spinlock problem in blk_throtl_exit md: correctly handle probe of an 'mdp' device. md: don't set_capacity before array is active. md: Fix raid1->raid0 takeover
2011-02-24block: bd_link_disk_holder() should hold on to holder_dirTejun Heo
The new implementation of bd_link_disk_holder() added by 49731baa41d (block: restore multiple bd_link_disk_holder() support) didn't get an extra reference for the holder_dir kobject of the slave bdev; however, bdev kills holder_dir on removal, not release, so if the slave bdev is removed while there are holder links, the holder_dir will be destroyed while there still are holder links, which leads to oops later when bd_unlink_disk_order() tries to remove those links. Make bd_link_disk_holder() grab an extra reference for the slave's holder_dir and put it in bd_unlink_disk_holder(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com> Tested-by: "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com> Cc: Neil Brown <neilb@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-24Fix over-zealous flush_disk when changing device size.NeilBrown
There are two cases when we call flush_disk. In one, the device has disappeared (check_disk_change) so any data will hold becomes irrelevant. In the oter, the device has changed size (check_disk_size_change) so data we hold may be irrelevant. In both cases it makes sense to discard any 'clean' buffers, so they will be read back from the device if needed. In the former case it makes sense to discard 'dirty' buffers as there will never be anywhere safe to write the data. In the second case it *does*not* make sense to discard dirty buffers as that will lead to file system corruption when you simply enlarge the containing devices. flush_disk calls __invalidate_devices. __invalidate_device calls both invalidate_inodes and invalidate_bdev. invalidate_inodes *does* discard I_DIRTY inodes and this does lead to fs corruption. invalidate_bev *does*not* discard dirty pages, but I don't really care about that at present. So this patch adds a flag to __invalidate_device (calling it __invalidate_device2) to indicate whether dirty buffers should be killed, and this is passed to invalidate_inodes which can choose to skip dirty inodes. flusk_disk then passes true from check_disk_change and false from check_disk_size_change. dm avoids tripping over this problem by calling i_size_write directly rathher than using check_disk_size_change. md does use check_disk_size_change and so is affected. This regression was introduced by commit 608aeef17a which causes check_disk_size_change to call flush_disk, so it is suitable for any kernel since 2.6.27. Cc: stable@kernel.org Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-17block: revert block_dev read-only checkChuck Ebbert
This reverts commit 75f1dc0d076d ("block: check bdev_read_only() from blkdev_get()"). That commit added stricter checking to make sure devices that were being used read-only were actually opened in that mode. It turns out that the change breaks a bunch of kernel code that opens block devices. Affected systems include dm, md, and the loop device. Because strict checking for read-only opens of block devices was not done before this, the code that opens the devices was opening them read-write even if they were being used read-only. Auditing all that code will take time, and new userspace packages for dm, mdadm, etc. will also be required. Signed-off-by: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-14block: restore multiple bd_link_disk_holder() supportTejun Heo
Commit e09b457b (block: simplify holder symlink handling) incorrectly assumed that there is only one link at maximum. dm may use multiple links and expects block layer to track reference count for each link, which is different from and unrelated to the exclusive device holder identified by @holder when the device is opened. Remove the single holder assumption and automatic removal of the link and revive the per-link reference count tracking. The code essentially behaves the same as before commit e09b457b sans the unnecessary kobject reference count dancing. While at it, note that this facility should not be used by anyone else than the current ones. Sysfs symlinks shouldn't be abused like this and the whole thing doesn't belong in the block layer at all. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Milan Broz <mbroz@redhat.com> Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-13Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits) block: ensure that completion error gets properly traced blktrace: add missing probe argument to block_bio_complete block cfq: don't use atomic_t for cfq_group block cfq: don't use atomic_t for cfq_queue block: trace event block fix unassigned field block: add internal hd part table references block: fix accounting bug on cross partition merges kref: add kref_test_and_get bio-integrity: mark kintegrityd_wq highpri and CPU intensive block: make kblockd_workqueue smarter Revert "sd: implement sd_check_events()" block: Clean up exit_io_context() source code. Fix compile warnings due to missing removal of a 'ret' variable fs/block: type signature of major_to_index(int) to major_to_index(unsigned) block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p) cfq-iosched: don't check cfqg in choose_service_tree() fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors cdrom: export cdrom_check_events() sd: implement sd_check_events() sr: implement sr_check_events() ...
2011-01-13pass default dentry_operations to mount_pseudo()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-07fs: icache RCU free inodesNick Piggin
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-12-16implement in-kernel gendisk events handlingTejun Heo
Currently, media presence polling for removeable block devices is done from userland. There are several issues with this. * Polling is done by periodically opening the device. For SCSI devices, the command sequence generated by such action involves a few different commands including TEST_UNIT_READY. This behavior, while perfectly legal, is different from Windows which only issues single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some ATAPI devices lock up after being periodically queried such command sequences. * There is no reliable and unintrusive way for a userland program to tell whether the target device is safe for media presence polling. For example, polling for media presence during an on-going burning session can make it fail. The polling program can avoid this by opening the device with O_EXCL but then it risks making a valid exclusive user of the device fail w/ -EBUSY. * Userland polling is unnecessarily heavy and in-kernel implementation is lighter and better coordinated (workqueue, timer slack). This patch implements framework for in-kernel disk event handling, which includes media presence polling. * bdops->check_events() is added, which supercedes ->media_changed(). It should check whether there's any pending event and return if so. Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be called parallelly. * gendisk->events and ->async_events are added. These should be initialized by block driver before passing the device to add_disk(). The former contains the mask of all supported events and the latter the mask of all events which the device can report without polling. /sys/block/*/events[_async] export these to userland. * Kernel parameter block.events_dfl_poll_msecs controls the system polling interval (default is 0 which means disable) and /sys/block/*/events_poll_msecs control polling intervals for individual devices (default is -1 meaning use system setting). Note that if a device can report all supported events asynchronously and its polling interval isn't explicitly set, the device won't be polled regardless of the system polling interval. * If a device is opened exclusively with write access, event checking is automatically disabled until all write exclusive accesses are released. * There are event 'clearing' events. For example, both of currently defined events are cleared after the device has been successfully opened. This information is passed to ->check_events() callback using @clearing argument as a hint. * Event checking is always performed from system_nrt_wq and timer slack is set to 25% for polling. * Nothing changes for drivers which implement ->media_changed() but not ->check_events(). Going forward, all drivers will be converted to ->check_events() and ->media_change() will be dropped. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-13block: clean up blkdev_get() wrappers and their usersTejun Heo
After recent blkdev_get() modifications, open_by_devnum() and open_bdev_exclusive() are simple wrappers around blkdev_get(). Replace them with blkdev_get_by_dev() and blkdev_get_by_path(). blkdev_get_by_dev() is identical to open_by_devnum(). blkdev_get_by_path() is slightly different in that it doesn't automatically add %FMODE_EXCL to @mode. All users are converted. Most conversions are mechanical and don't introduce any behavior difference. There are several exceptions. * btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no reason to OR it explicitly on blkdev_put(). * gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in sb->s_mode. * With the above changes, sb->s_mode now always should contain FMODE_EXCL. WARN_ON_ONCE() added to kill_block_super() to detect errors. The new blkdev_get_*() functions are with proper docbook comments. While at it, add function description to blkdev_get() too. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Joern Engel <joern@lazybastard.org> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jan Kara <jack@suse.cz> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: reiserfs-devel@vger.kernel.org Cc: xfs-masters@oss.sgi.com Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13block: check bdev_read_only() from blkdev_get()Tejun Heo
bdev read-only status can be queried using bdev_read_only() and may change while the device is being opened. Enforce it by checking it from blkdev_get() after open succeeds. This makes bdev_read_only() check in open_bdev_exclusive() and fsg_lun_open() unnecessary. Drop them. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: linux-usb@vger.kernel.org
2010-11-13block: reorganize claim/release implementationTejun Heo
With claim/release rolled into blkdev_get/put(), there's no reason to keep bd_abort/finish_claim(), __bd_claim() and bd_release() as separate functions. It only makes the code difficult to follow. Collapse them into blkdev_get/put(). This will ease future changes around claim/release. Signed-off-by: Tejun Heo <tj@kernel.org>
2010-11-13block: make blkdev_get/put() handle exclusive accessTejun Heo
Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13block: simplify holder symlink handlingTejun Heo
Code to manage symlinks in /sys/block/*/{holders|slaves} are overly complex with multiple holder considerations, redundant extra references to all involved kobjects, unused generic kobject holder support and unnecessary mixup with bd_claim/release functionalities. Strip it down to what's necessary (single gendisk holder) and make it use a separate interface. This is a step for cleaning up bd_claim/release. This patch makes dm-table slightly more complex but it will be simplified again with further changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com
2010-10-29convert get_sb_pseudo() usersAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-26fs: inode split IO and LRU listsNick Piggin
The use of the same inode list structure (inode->i_list) for two different list constructs with different lifecycles and purposes makes it impossible to separate the locking of the different operations. Therefore, to enable the separation of the locking of the writeback and reclaim lists, split the inode->i_list into two separate lists dedicated to their specific tracking functions. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-26fs: switch bdev inode bdi's correctlyDave Chinner
bdev inodes can remain dirty even after their last close. Hence the BDI associated with the bdev->inode gets modified duringthe last close to point to the default BDI. However, the bdev inode still needs to be moved to the dirty lists of the new BDI, otherwise it will corrupt the writeback list is was left on. Add a new function bdev_inode_switch_bdi() to move all the bdi state from the old bdi to the new one safely. This is only a temporary measure until the bdev inode<->bdi lifecycle problems are sorted out. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-26new helper: ihold()Al Viro
Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-09-16block: remove BLKDEV_IFL_WAITChristoph Hellwig
All the blkdev_issue_* helpers can only sanely be used for synchronous caller. To issue cache flushes or barriers asynchronously the caller needs to set up a bio by itself with a completion callback to move the asynchronous state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always specified when calling blkdev_issue_* and also remove the now unused flags argument to blkdev_issue_flush and blkdev_issue_zeroout. For blkdev_issue_discard we need to keep it for the secure discard flag, which gains a more descriptive name and loses the bitops vs flag confusion. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-11blkdev: cgroup whitelist permission fixChris Wright
The cgroup device whitelist code gets confused when trying to grant permission to a disk partition that is not currently open. Part of blkdev_open() includes __blkdev_get() on the whole disk. Basically, the only ways to reliably allow a cgroup access to a partition on a block device when using the whitelist are to 1) also give it access to the whole block device or 2) make sure the partition is already open in a different context. The patch avoids the cgroup check for the whole disk case when opening a partition. Addresses https://bugzilla.redhat.com/show_bug.cgi?id=589662 Signed-off-by: Chris Wright <chrisw@sous-sol.org> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Serge E. Hallyn <serue@us.ibm.com> Reported-by: Vivek Goyal <vgoyal@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: "Daniel P. Berrange" <berrange@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits) block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n xen-blkfront: fix missing out label blkdev: fix blkdev_issue_zeroout return value block: update request stacking methods to support discards block: fix missing export of blk_types.h writeback: fix bad _bh spinlock nesting drbd: revert "delay probes", feature is being re-implemented differently drbd: Initialize all members of sync_conf to their defaults [Bugz 315] drbd: Disable delay probes for the upcomming release writeback: cleanup bdi_register writeback: add new tracepoints writeback: remove unnecessary init_timer call writeback: optimize periodic bdi thread wakeups writeback: prevent unnecessary bdi threads wakeups writeback: move bdi threads exiting logic to the forker thread writeback: restructure bdi forker loop a little writeback: move last_active to bdi writeback: do not remove bdi from bdi_list writeback: simplify bdi code a little writeback: do not lose wake-ups in bdi threads ... Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and drivers/scsi/scsi_error.c as per Jens.
2010-08-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits) no need for list_for_each_entry_safe()/resetting with superblock list Fix sget() race with failing mount vfs: don't hold s_umount over close_bdev_exclusive() call sysv: do not mark superblock dirty on remount sysv: do not mark superblock dirty on mount btrfs: remove junk sb_dirt change BFS: clean up the superblock usage AFFS: wait for sb synchronization when needed AFFS: clean up dirty flag usage cifs: truncate fallout mbcache: fix shrinker function return value mbcache: Remove unused features add f_flags to struct statfs(64) pass a struct path to vfs_statfs update VFS documentation for method changes. All filesystems that need invalidate_inode_buffers() are doing that explicitly convert remaining ->clear_inode() to ->evict_inode() Make ->drop_inode() just return whether inode needs to be dropped fs/inode.c:clear_inode() is gone fs/inode.c:evict() doesn't care about delete vs. non-delete paths now ... Fix up trivial conflicts in fs/nilfs2/super.c
2010-08-09convert remaining ->clear_inode() to ->evict_inode()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09get rid of block_write_begin_newtruncChristoph Hellwig
Move the call to vmtruncate to get rid of accessive blocks to the callers in preparation of the new truncate sequence and rename the non-truncating version to block_write_begin. While we're at it also remove several unused arguments to block_write_begin. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09sort out blockdev_direct_IO variantsChristoph Hellwig
Move the call to vmtruncate to get rid of accessive blocks to the callers in prepearation of the new truncate calling sequence. This was only done for DIO_LOCKING filesystems, so the __blockdev_direct_IO_newtrunc variant was not needed anyway. Get rid of blockdev_direct_IO_no_locking and its _newtrunc variant while at it as just opencoding the two additional paramters is shorted than the name suffix. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-07block: push down BKL into .open and .releaseArnd Bergmann
The open and release block_device_operations are currently called with the BKL held. In order to change that, we must first make sure that all drivers that currently rely on this have no regressions. This blindly pushes the BKL into all .open and .release operations for all block drivers to prepare for the next step. The drivers can subsequently replace the BKL with their own locks or remove it completely when it can be shown that it is not needed. The functions blkdev_get and blkdev_put are the only remaining users of the big kernel lock in the block layer, besides a few uses in the ioctl code, none of which need to serialize with blkdev_{get,put}. Most of these two functions is also under the protection of bdev->bd_mutex, including the actual calls to ->open and ->release, and the common code does not access any global data structures that need the BKL. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-04block_dev: always serialize exclusive open attemptsTejun Heo
bd_prepare_to_claim() incorrectly allowed multiple attempts for exclusive open to progress in parallel if the attempting holders are identical. This triggered BUG_ON() as reported in the following bug. https://bugzilla.kernel.org/show_bug.cgi?id=16393 __bd_abort_claiming() is used to finish claiming blocks and doesn't work if multiple openers are inside a claiming block. Allowing multiple parallel open attempts to continue doesn't gain anything as those are serialized down in the call chain anyway. Fix it by always allowing only single open attempt in a claiming block. This problem can easily be reproduced by adding a delay after bd_prepare_to_claim() and attempting to mount two partitions of a disk. stable: only applicable to v2.6.35 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-10block: remove duplicate BUG_ON() in bd_finish_claiming()Jens Axboe
We do the same BUG_ON() just a line later when calling into __bd_abort_claiming(). Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-10block: bd_start_claiming cleanupNick Piggin
I don't like the subtle multi-context code in bd_claim (ie. detects where it has been called based on bd_claiming). It seems clearer to just require a new function to finish a 2-part claim. Also improve commentary in bd_start_claiming as to how it should be used. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-10block: bd_start_claiming fix module refcountNick Piggin
bd_start_claiming has an unbalanced module_put introduced in 6b4517a79. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-28fs: convert simple fs to new truncateNick Piggin
Convert simple filesystems: ramfs, configfs, sysfs, block_dev to new truncate sequence. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-28drop unused dentry argument to ->fsyncChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits) fix handling of offsets in cris eeprom.c, get rid of fake on-stack files get rid of home-grown mutex in cris eeprom.c switch ecryptfs_write() to struct inode *, kill on-stack fake files switch ecryptfs_get_locked_page() to struct inode * simplify access to ecryptfs inodes in ->readpage() and friends AFS: Don't put struct file on the stack Ban ecryptfs over ecryptfs logfs: replace inode uid,gid,mode initialization with helper function ufs: replace inode uid,gid,mode initialization with helper function udf: replace inode uid,gid,mode init with helper ubifs: replace inode uid,gid,mode initialization with helper function sysv: replace inode uid,gid,mode initialization with helper function reiserfs: replace inode uid,gid,mode initialization with helper function ramfs: replace inode uid,gid,mode initialization with helper function omfs: replace inode uid,gid,mode initialization with helper function bfs: replace inode uid,gid,mode initialization with helper function ocfs2: replace inode uid,gid,mode initialization with helper function nilfs2: replace inode uid,gid,mode initialization with helper function minix: replace inode uid,gid,mode init with helper ext4: replace inode uid,gid,mode init with helper ... Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
2010-05-21Introduce freeze_super and thaw_super for the fsfreeze ioctlJosef Bacik
Currently the way we do freezing is by passing sb>s_bdev to freeze_bdev and then letting it do all the work. But freezing is more of an fs thing, and doesn't really have much to do with the bdev at all, all the work gets done with the super. In btrfs we do not populate s_bdev, since we can have multiple bdev's for one fs and setting s_bdev makes removing devices from a pool kind of tricky. This means that freezing a btrfs filesystem fails, which causes us to corrupt with things like tux-on-ice which use the fsfreeze mechanism. So instead of populating sb->s_bdev with a random bdev in our pool, I've broken the actual fs freezing stuff into freeze_super and thaw_super. These just take the super_block that we're freezing and does the appropriate work. It's basically just copy and pasted from freeze_bdev. I've then converted freeze_bdev over to use the new super helpers. I've tested this with ext4 and btrfs and verified everything continues to work the same as before. The only new gotcha is multiple calls to the fsfreeze ioctl will return EBUSY if the fs is already frozen. I thought this was a better solution than adding a freeze counter to the super_block, but if everybody hates this idea I'm open to suggestions. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21Move grabbing s_umount to callers of grab_super()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-04-29Merge branch 'master' into for-2.6.35Jens Axboe
Conflicts: fs/block_dev.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28blkdev: generalize flags for blkdev_issue_fn functionsDmitry Monakhov
The patch just convert all blkdev_issue_xxx function to common set of flags. Wait/allocation semantics preserved. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27block: implement bd_claiming and claiming blockTejun Heo
Currently, device claiming for exclusive open is done after low level open - disk->fops->open() - has completed successfully. This means that exclusive open attempts while a device is already exclusively open will fail only after disk->fops->open() is called. cdrom driver issues commands during open() which means that O_EXCL open attempt can unintentionally inject commands to in-progress command stream for burning thus disturbing burning process. In most cases, this doesn't cause problems because the first command to be issued is TUR which most devices can process in the middle of burning. However, depending on how a device replies to TUR during burning, cdrom driver may end up issuing further commands. This can't be resolved trivially by moving bd_claim() before doing actual open() because that means an open attempt which will end up failing could interfere other legit O_EXCL open attempts. ie. unconfirmed open attempts can fail others. This patch resolves the problem by introducing claiming block which is started by bd_start_claiming() and terminated either by bd_claim() or bd_abort_claiming(). bd_claim() from inside a claiming block is guaranteed to succeed and once a claiming block is started, other bd_start_claiming() or bd_claim() attempts block till the current claiming block is terminated. bd_claim() can still be used standalone although now it always synchronizes against claiming blocks, so the existing users will keep working without any change. blkdev_open() and open_bdev_exclusive() are converted to use claiming blocks so that exclusive open attempts from these functions don't interfere with the existing exclusive open. This problem was discovered while investigating bko#15403. https://bugzilla.kernel.org/show_bug.cgi?id=15403 The burning problem itself can be resolved by updating userspace probing tools to always open w/ O_EXCL. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Matthias-Christian Ott <ott@mirix.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27block: factor out bd_may_claim()Tejun Heo
Factor out bd_may_claim() from bd_claim(), add comments and apply a couple of cosmetic edits. This is to prepare for further updates to claim path. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-24fs/block_dev.c: fix performance regression in O_DIRECT|O_SYNC writes to ↵Anton Blanchard
block devices We are seeing a large regression in database performance on recent kernels. The database opens a block device with O_DIRECT|O_SYNC and a number of threads write to different regions of the file at the same time. A simple test case is below. I haven't defined DEVICE since getting it wrong will destroy your data :) On an 3 disk LVM with a 64k chunk size we see about 17MB/sec and only a few threads in IO wait: procs -----io---- -system-- -----cpu------ r b bi bo in cs us sy id wa st 0 3 0 16170 656 2259 0 0 86 14 0 0 2 0 16704 695 2408 0 0 92 8 0 0 2 0 17308 744 2653 0 0 86 14 0 0 2 0 17933 759 2777 0 0 89 10 0 Most threads are blocking in vfs_fsync_range, which has: mutex_lock(&mapping->host->i_mutex); err = fop->fsync(file, dentry, datasync); if (!ret) ret = err; mutex_unlock(&mapping->host->i_mutex); commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode) offers some explanation of what is going on: Use these new helpers for syncing from generic VFS functions. This makes O_SYNC writes to block devices acquire i_mutex for syncing. If we really care about this, we can make block_fsync() drop the i_mutex and reacquire it before it returns. Thanks Jan for such a good commit message! As well as dropping i_mutex, Christoph suggests we should remove the call to sync_blockdev(): > sync_blockdev is an overcomplicated alias for filemap_write_and_wait on > the block device inode, which is exactly what we did just before calling > into ->fsync The patch below incorporates both suggestions. With it the testcase improves from 17MB/s to 68M/sec: procs -----io---- -system-- -----cpu------ r b bi bo in cs us sy id wa st 0 7 0 65536 1000 3878 0 0 70 30 0 0 34 0 69632 1016 3921 0 1 46 53 0 0 57 0 69632 1000 3921 0 0 55 45 0 0 53 0 69640 754 4111 0 0 81 19 0 Testcase: #define _GNU_SOURCE #include <stdio.h> #include <pthread.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #define NR_THREADS 64 #define BUFSIZE (64 * 1024) #define DEVICE "/dev/mapper/XXXXXX" #define ALIGN(VAL, SIZE) (((VAL)+(SIZE)-1) & ~((SIZE)-1)) static int fd; static void *doit(void *arg) { unsigned long offset = (long)arg; char *b, *buf; b = malloc(BUFSIZE + 1024); buf = (char *)ALIGN((unsigned long)b, 1024); memset(buf, 0, BUFSIZE); while (1) pwrite(fd, buf, BUFSIZE, offset); } int main(int argc, char *argv[]) { int flags = O_RDWR|O_DIRECT; int i; unsigned long offset = 0; if (argc > 1 && !strcmp(argv[1], "O_SYNC")) flags |= O_SYNC; fd = open(DEVICE, flags); if (fd == -1) { perror("open"); exit(1); } for (i = 0; i < NR_THREADS-1; i++) { pthread_t tid; pthread_create(&tid, NULL, doit, (void *)offset); offset += BUFSIZE; } doit((void *)offset); return 0; } Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07vfs: rename block_fsync() to blkdev_fsync()Andrew Morton
Requested by hch, for consistency now it is exported. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Anton Blanchard <anton@samba.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07raw: fsync method is now requiredAnton Blanchard
Commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode) broke the raw driver. We now call through generic_file_aio_write -> generic_write_sync -> vfs_fsync_range. vfs_fsync_range has: if (!fop || !fop->fsync) { ret = -EINVAL; goto out; } But drivers/char/raw.c doesn't set an fsync method. We have two options: fix it or remove the raw driver completely. I'm happy to do either, the fact this has been broken for so long suggests it is rarely used. The patch below adds an fsync method to the raw driver. My knowledge of the block layer is pretty sketchy so this could do with a once over. If we instead decide to remove the raw driver, this patch might still be useful as a backport to 2.6.33 and 2.6.32. Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <jens.axboe@oracle.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Tested-by: Jeff Moyer <jmoyer@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-07freeze_bdev: don't deactivate successfully frozen MS_RDONLY sbJun'ichi Nomura
Thanks Thomas and Christoph for testing and review. I removed 'smp_wmb()' before up_write from the previous patch, since up_write() should have necessary ordering constraints. (I.e. the change of s_frozen is visible to others after up_write) I'm quite sure the change is harmless but if you are uncomfortable with Tested-by/Reviewed-by on the modified patch, please remove them. If MS_RDONLY, freeze_bdev should just up_write(s_umount) instead of deactivate_locked_super(). Also, keep sb->s_frozen consistent so that remount can check the frozen state. Otherwise a crash reported here can happen: http://lkml.org/lkml/2010/1/16/37 http://lkml.org/lkml/2010/1/28/53 This patch should be applied for 2.6.32 stable series, too. Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Thomas Backlund <tmb@mandriva.org> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-11-03Merge branch 'for-linus' into for-2.6.33Jens Axboe
Conflicts: block/cfq-iosched.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-29blkdev: flush disk cache on ->fsyncChristoph Hellwig
Currently there is no barrier support in the block device code. That means we cannot guarantee any sort of data integerity when using the block device node with dis kwrite caches enabled. Using the raw block device node is a typical use case for virtualization (and I assume databases, too). This patch changes block_fsync to issue a cache flush and thus make fsync on block device nodes actually useful. Note that in mainline we would also need to add such code to the ->aio_write method for O_SYNC handling, but assuming that Jan's patch series for the O_SYNC rewrite goes in it will also call into ->fsync for 2.6.32. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-26block: use after free bug in __blkdev_getNeil Brown
commit 0762b8bde9729f10f8e6249809660ff2ec3ad735 (from 14 months ago) introduced a use-after-free bug which has just recently started manifesting in my md testing. I tried git bisect to find out what caused the bug to start manifesting, and it could have been the recent change to blk_unregister_queue (48c0d4d4c04) but the results were inconclusive. This patch certainly fixes my symptoms and looks correct as the two calls are now in the same order as elsewhere in that function. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-24freeze_bdev: grab active reference to frozen superblocksChristoph Hellwig
Currently we held s_umount while a filesystem is frozen, despite that we might return to userspace and unlock it from a different process. Instead grab an active reference to keep the file system busy and add an explicit check for frozen filesystems in remount and reject the remount instead of blocking on s_umount. Add a new get_active_super helper to super.c for use by freeze_bdev that grabs an active reference to a superblock from a given block device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24freeze_bdev: kill bd_mount_semChristoph Hellwig
Now that we have the freeze count there is not much reason for bd_mount_sem anymore. The actual freeze/thaw operations are serialized using the bd_fsfreeze_mutex, and the only other place we take bd_mount_sem is get_sb_bdev which tries to prevent mounting a filesystem while the block device is frozen. Instead of add a check for bd_fsfreeze_count and return -EBUSY if a filesystem is frozen. While that is a change in user visible behaviour a failing mount is much better for this case rather than having the mount process stuck uninterruptible for a long time. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>