linux/fs/block_dev.c, branch v3.1

Avoid dereferencing a 'request_queue' after last close.

2011-09-10T07:20:21Z

On the last close of an 'md' device which as been stopped, the device is destroyed and in particular the request_queue is freed. The free is done in a separate thread so it might happen a short time later. __blkdev_put calls bdev_inode_switch_bdi *after* ->release has been called. Since commit f758eeabeb96f878c860e8f110f94ec8820822a9 bdev_inode_switch_bdi will dereference the 'old' bdi, which lives inside a request_queue, to get a spin lock. This causes the last close on an md device to sometime take a spin_lock which lives in freed memory - which results in an oops. So move the called to bdev_inode_switch_bdi before the call to ->release. Cc: Christoph Hellwig Cc: Hugh Dickins Cc: Andrew Morton Cc: Wu Fengguang Acked-by: Wu Fengguang Cc: stable@kernel.org Signed-off-by: NeilBrown

fix block device fallout from ->fsync() changes

2011-08-02T01:33:47Z

blkdev_fsync() needs to write pages in pagecache... Signed-off-by: Rafael J. Wysocki Signed-off-by: Al Viro

block: initialise bd_super in bdget()

2011-08-01T05:57:44Z

bd_super is currently reset to NULL in kill_block_super() so we rely on previous users of the block_device object to initialise this value for the next user. This quirk was exposed on RHEL5 when a third party filesystem did not always use kill_block_super() and therefore bd_super wasn't being reset when a block_device object was recycled within the cache. This may not be a problem upstream but makes sense to be defensive. Signed-off-by: Lachlan McIlroy Reviewed-by: Eric Sandeen Signed-off-by: Al Viro

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback

2011-07-26T17:39:54Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback: (27 commits) mm: properly reflect task dirty limits in dirty_exceeded logic writeback: don't busy retry writeback on new/freeing inodes writeback: scale IO chunk size up to half device bandwidth writeback: trace global_dirty_state writeback: introduce max-pause and pass-good dirty limits writeback: introduce smoothed global dirty limit writeback: consolidate variable names in balance_dirty_pages() writeback: show bdi write bandwidth in debugfs writeback: bdi write bandwidth estimation writeback: account per-bdi accumulated written pages writeback: make writeback_control.nr_to_write straight writeback: skip tmpfs early in balance_dirty_pages_ratelimited_nr() writeback: trace event writeback_queue_io writeback: trace event writeback_single_inode writeback: remove .nonblocking and .encountered_congestion writeback: remove writeback_control.more_io writeback: skip balance_dirty_pages() for in-memory fs writeback: add bdi_dirty_limit() kernel-doc writeback: avoid extra sync work at enqueue time writeback: elevate queue_io() into wb_writeback() ... Fix up trivial conflicts in fs/fs-writeback.c and mm/filemap.c

Merge branch 'for-3.1/core' of git://git.kernel.dk/linux-block

2011-07-25T17:33:36Z

* 'for-3.1/core' of git://git.kernel.dk/linux-block: (24 commits) block: strict rq_affinity backing-dev: use synchronize_rcu_expedited instead of synchronize_rcu block: fix patch import error in max_discard_sectors check block: reorder request_queue to remove 64 bit alignment padding CFQ: add think time check for group CFQ: add think time check for service tree CFQ: move think time check variables to a separate struct fixlet: Remove fs_excl from struct task. cfq: Remove special treatment for metadata rqs. block: document blk_plug list access block: avoid building too big plug list compat_ioctl: fix make headers_check regression block: eliminate potential for infinite loop in blkdev_issue_discard compat_ioctl: fix warning caused by qemu block: flush MEDIA_CHANGE from drivers on close(2) blk-throttle: Make total_nr_queued unsigned block: Add __attribute__((format(printf...) and fix fallout fs/partitions/check.c: make local symbols static block:remove some spare spaces in genhd.c block:fix the comment error in blkdev.h ...

fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers

2011-07-21T00:47:59Z

Btrfs needs to be able to control how filemap_write_and_wait_range() is called in fsync to make it less of a painful operation, so push down taking i_mutex and the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some file systems can drop taking the i_mutex altogether it seems, like ext3 and ocfs2. For correctness sake I just pushed everything down in all cases to make sure that we keep the current behavior the same for everybody, and then each individual fs maintainer can make up their mind about what to do from there. Thanks, Acked-by: Jan Kara Signed-off-by: Josef Bacik Signed-off-by: Al Viro

fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek

2011-07-21T00:47:58Z

This converts everybody to handle SEEK_HOLE/SEEK_DATA properly. In some cases we just return -EINVAL, in others we do the normal generic thing, and in others we're simply making sure that the properly due-dilligence is done. For example in NFS/CIFS we need to make sure the file size is update properly for the SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself that is all we have to do. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Al Viro

block: flush MEDIA_CHANGE from drivers on close(2)

2011-07-01T14:17:47Z

Currently, only open(2) is defined as the 'clearing' point. It has two roles - first, it's an acknowledgement from userland indicating that the event has been received and kernel can clear pending states and proceed to generate more events. Secondly, it's passed on to device drivers as a hint indicating that a synchronization point has been reached and it might want to take a deeper look at the device. The latter currently is only used by sr which uses two different mechanisms - GET_EVENT_MEDIA_STATUS_NOTIFICATION and TEST_UNIT_READY to discover events, where the former is lighter weight and safe to be used repeatedly but may not provide full coverage. Among other things, GET_EVENT can't detect media removal while TUR can. This patch makes close(2) - blkdev_put() - indicate clearing hint for MEDIA_CHANGE to drivers. disk_check_events() is renamed to disk_flush_events() and updated to take @mask for events to flush which is or'd to ev->clearing and will be passed to the driver on the next ->check_events() invocation. This change makes sr generate MEDIA_CHANGE when media is ejected from userland - e.g. with eject(1). Note: Given the current usage, it seems @clearing hint is needlessly complex. disk_clear_events() can simply clear all events and the hint can be boolean @flush. Signed-off-by: Tejun Heo Cc: Kay Sievers Signed-off-by: Jens Axboe

block: use the passed in @bdev when claiming if partno is zero

2011-06-13T10:45:48Z

6b4517a791 (block: implement bd_claiming and claiming block) introduced claiming block to support O_EXCL blkdev opens properly. bd_start_claiming() looks up the part 0 bdev and starts claiming block. The function assumed that there is only one part 0 bdev and always used bdget_disk(disk, 0) to look it up; unfortunately, this isn't true for some drivers (floppy) which use multiple block devices to denote different operating parameters for the same physical device. There can be multiple part 0 bdev's for the same device number. This incorrect assumption caused the wrong bdev to be used during claiming leading to unbalanced bd_holders as reported in the following bug. https://bugzilla.kernel.org/show_bug.cgi?id=28522 This patch updates bd_start_claiming() such that it uses the bdev specified as argument if its partno is zero. Note that this means that different bdev's can be used for the same device and O_EXCL check can be effectively bypassed. It has always been broken that way and floppy is fortunately on its way out. Leave that breakage alone. Signed-off-by: Tejun Heo Reported-by: Alex Villacis Lasso Tested-by: Alex Villacis Lasso Cc: stable@kernel.org # >= v2.6.36 Signed-off-by: Jens Axboe

writeback: split inode_wb_list_lock into bdi_writeback.list_lock

2011-06-08T00:25:21Z

Split the global inode_wb_list_lock into a per-bdi_writeback list_lock, as it's currently the most contended lock in the system for metadata heavy workloads. It won't help for single-filesystem workloads for which we'll need the I/O-less balance_dirty_pages, but at least we can dedicate a cpu to spinning on each bdi now for larger systems. Based on earlier patches from Nick Piggin and Dave Chinner. It reduces lock contentions to 1/4 in this test case: 10 HDD JBOD, 100 dd on each disk, XFS, 6GB ram lock_stat version 0.3 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- vanilla 2.6.39-rc3: inode_wb_list_lock: 42590 44433 0.12 147.74 144127.35 252274 886792 0.08 121.34 917211.23 ------------------ inode_wb_list_lock 2 [] bdev_inode_switch_bdi+0x29/0x85 inode_wb_list_lock 34 [] inode_wb_list_del+0x22/0x49 inode_wb_list_lock 12893 [] __mark_inode_dirty+0x170/0x1d0 inode_wb_list_lock 10702 [] writeback_single_inode+0x16d/0x20a ------------------ inode_wb_list_lock 2 [] bdev_inode_switch_bdi+0x29/0x85 inode_wb_list_lock 19 [] inode_wb_list_del+0x22/0x49 inode_wb_list_lock 5550 [] __mark_inode_dirty+0x170/0x1d0 inode_wb_list_lock 8511 [] writeback_sb_inodes+0x10f/0x157 2.6.39-rc3 + patch: &(&wb->list_lock)->rlock: 11383 11657 0.14 151.69 40429.51 90825 527918 0.11 145.90 556843.37 ------------------------ &(&wb->list_lock)->rlock 10 [] inode_wb_list_del+0x5f/0x86 &(&wb->list_lock)->rlock 1493 [] writeback_inodes_wb+0x3d/0x150 &(&wb->list_lock)->rlock 3652 [] writeback_sb_inodes+0x123/0x16f &(&wb->list_lock)->rlock 1412 [] writeback_single_inode+0x17f/0x223 ------------------------ &(&wb->list_lock)->rlock 3 [] bdi_lock_two+0x46/0x4b &(&wb->list_lock)->rlock 6 [] inode_wb_list_del+0x5f/0x86 &(&wb->list_lock)->rlock 2061 [] __mark_inode_dirty+0x173/0x1cf &(&wb->list_lock)->rlock 2629 [] writeback_sb_inodes+0x123/0x16f hughd@google.com: fix recursive lock when bdi_lock_two() is called with new the same as old akpm@linux-foundation.org: cleanup bdev_inode_switch_bdi() comment Signed-off-by: Christoph Hellwig Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Wu Fengguang