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* lseek: the "whence" argument is called "whence"Andrew Morton2012-12-17
| | | | | | | | | But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: fix O_DIRECT read past end of block deviceLinus Torvalds2012-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The direct-IO write path already had the i_size checks in mm/filemap.c, but it turns out the read path did not, and removing the block size checks in fs/block_dev.c (commit bbec0270bdd8: "blkdev_max_block: make private to fs/buffer.c") removed the magic "shrink IO to past the end of the device" code there. Fix it by truncating the IO to the size of the block device, like the write path already does. NOTE! I suspect the write path would be *much* better off doing it this way in fs/block_dev.c, rather than hidden deep in mm/filemap.c. The mm/filemap.c code is extremely hard to follow, and has various conditionals on the target being a block device (ie the flag passed in to 'generic_write_checks()', along with a conditional update of the inode timestamp etc). It is also quite possible that we should treat this whole block device size as a "s_maxbytes" issue, and try to make the logic even more generic. However, in the meantime this is the fairly minimal targeted fix. Noted by Milan Broz thanks to a regression test for the cryptsetup reencrypt tool. Reported-and-tested-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* blkdev_max_block: make private to fs/buffer.cLinus Torvalds2012-11-29
| | | | | | | | | | | | We really don't want to look at the block size for the raw block device accesses in fs/block-dev.c, because it may be changing from under us. So get rid of the max_block logic entirely, since the caller should already have done it anyway. That leaves the only user of this function in fs/buffer.c, so move the whole function there and make it static. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* blockdev: remove bd_block_size_semaphore againLinus Torvalds2012-11-29
| | | | | | | | | | This reverts the block-device direct access code to the previous unlocked code, now that fs/buffer.c no longer needs external locking. With this, fs/block_dev.c is back to the original version, apart from a whitespace cleanup that I didn't want to revert. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Lock splice_read and splice_write functionsMikulas Patocka2012-10-28
| | | | | | | | | | | | | Functions generic_file_splice_read and generic_file_splice_write access the pagecache directly. For block devices these functions must be locked so that block size is not changed while they are in progress. This patch is an additional fix for commit b87570f5d349 ("Fix a crash when block device is read and block size is changed at the same time") that locked aio_read, aio_write and mmap against block size change. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-blockLinus Torvalds2012-10-10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO update from Jens Axboe: "Core block IO bits for 3.7. Not a huge round this time, it contains: - First series from Kent cleaning up and generalizing bio allocation and freeing. - WRITE_SAME support from Martin. - Mikulas patches to prevent O_DIRECT crashes when someone changes the block size of a device. - Make bio_split() work on data-less bio's (like trim/discards). - A few other minor fixups." Fixed up silent semantic mis-merge as per Mikulas Patocka and Andrew Morton. It is due to the VM no longer using a prio-tree (see commit 6b2dbba8b6ac: "mm: replace vma prio_tree with an interval tree"). So make set_blocksize() use mapping_mapped() instead of open-coding the internal VM knowledge that has changed. * 'for-3.7/core' of git://git.kernel.dk/linux-block: (26 commits) block: makes bio_split support bio without data scatterlist: refactor the sg_nents scatterlist: add sg_nents fs: fix include/percpu-rwsem.h export error percpu-rw-semaphore: fix documentation typos fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declared blockdev: turn a rw semaphore into a percpu rw semaphore Fix a crash when block device is read and block size is changed at the same time block: fix request_queue->flags initialization block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue() block: ioctl to zero block ranges block: Make blkdev_issue_zeroout use WRITE SAME block: Implement support for WRITE SAME block: Consolidate command flag and queue limit checks for merges block: Clean up special command handling logic block/blk-tag.c: Remove useless kfree block: remove the duplicated setting for congestion_threshold block: reject invalid queue attribute values block: Add bio_clone_bioset(), bio_clone_kmalloc() block: Consolidate bio_alloc_bioset(), bio_kmalloc() ...
| * fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declaredFengguang Wu2012-09-26
| | | | | | | | | | | | | | | | blkdev_mmap() isn't used outside of fs/block_dev.c, mark it as static. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blockdev: turn a rw semaphore into a percpu rw semaphoreMikulas Patocka2012-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This avoids cache line bouncing when many processes lock the semaphore for read. New percpu lock implementation The lock consists of an array of percpu unsigned integers, a boolean variable and a mutex. When we take the lock for read, we enter rcu read section, check for a "locked" variable. If it is false, we increase a percpu counter on the current cpu and exit the rcu section. If "locked" is true, we exit the rcu section, take the mutex and drop it (this waits until a writer finished) and retry. Unlocking for read just decreases percpu variable. Note that we can unlock on a difference cpu than where we locked, in this case the counter underflows. The sum of all percpu counters represents the number of processes that hold the lock for read. When we need to lock for write, we take the mutex, set "locked" variable to true and synchronize rcu. Since RCU has been synchronized, no processes can create new read locks. We wait until the sum of percpu counters is zero - when it is, there are no readers in the critical section. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * Fix a crash when block device is read and block size is changed at the same timeMikulas Patocka2012-09-26
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel may crash when block size is changed and I/O is issued simultaneously. Because some subsystems (udev or lvm) may read any block device anytime, the bug actually puts any code that changes a block device size in jeopardy. The crash can be reproduced if you place "msleep(1000)" to blkdev_get_blocks just before "bh->b_size = max_blocks << inode->i_blkbits;". Then, run "dd if=/dev/ram0 of=/dev/null bs=4k count=1 iflag=direct" While it is waiting in msleep, run "blockdev --setbsz 2048 /dev/ram0" You get a BUG. The direct and non-direct I/O is written with the assumption that block size does not change. It doesn't seem practical to fix these crashes one-by-one there may be many crash possibilities when block size changes at a certain place and it is impossible to find them all and verify the code. This patch introduces a new rw-lock bd_block_size_semaphore. The lock is taken for read during I/O. It is taken for write when changing block size. Consequently, block size can't be changed while I/O is being submitted. For asynchronous I/O, the patch only prevents block size change while the I/O is being submitted. The block size can change when the I/O is in progress or when the I/O is being finished. This is acceptable because there are no accesses to block size when asynchronous I/O is being finished. The patch prevents block size changing while the device is mapped with mmap. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devicesJianpeng Ma2012-08-02
| | | | | | | | | | For regular file, write operaion used blk_plug function.But for block file,write operation did not use blk_plug. This patch is also for write-cache mode for block-device. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* vfs: Create function for iterating over block devicesJan Kara2012-07-22
| | | | | Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linuxLinus Torvalds2012-05-28
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull writeback tree from Wu Fengguang: "Mainly from Jan Kara to avoid iput() in the flusher threads." * tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Avoid iput() from flusher thread vfs: Rename end_writeback() to clear_inode() vfs: Move waiting for inode writeback from end_writeback() to evict_inode() writeback: Refactor writeback_single_inode() writeback: Remove wb->list_lock from writeback_single_inode() writeback: Separate inode requeueing after writeback writeback: Move I_DIRTY_PAGES handling writeback: Move requeueing when I_SYNC set to writeback_sb_inodes() writeback: Move clearing of I_SYNC into inode_sync_complete() writeback: initialize global_dirty_limit fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds mm: page-writeback.c: local functions should not be exposed globally
| * vfs: Rename end_writeback() to clear_inode()Jan Kara2012-05-06
| | | | | | | | | | | | | | | | | | After we moved inode_sync_wait() from end_writeback() it doesn't make sense to call the function end_writeback() anymore. Rename it to clear_inode() which well says what the function really does - set I_CLEAR flag. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
* | block: don't mark buffers beyond end of disk as mappedJeff Moyer2012-05-11
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hi, We have a bug report open where a squashfs image mounted on ppc64 would exhibit errors due to trying to read beyond the end of the disk. It can easily be reproduced by doing the following: [root@ibm-p750e-02-lp3 ~]# ls -l install.img -rw-r--r-- 1 root root 142032896 Apr 30 16:46 install.img [root@ibm-p750e-02-lp3 ~]# mount -o loop ./install.img /mnt/test [root@ibm-p750e-02-lp3 ~]# dd if=/dev/loop0 of=/dev/null dd: reading `/dev/loop0': Input/output error 277376+0 records in 277376+0 records out 142016512 bytes (142 MB) copied, 0.9465 s, 150 MB/s In dmesg, you'll find the following: squashfs: version 4.0 (2009/01/31) Phillip Lougher [ 43.106012] attempt to access beyond end of device [ 43.106029] loop0: rw=0, want=277410, limit=277408 [ 43.106039] Buffer I/O error on device loop0, logical block 138704 [ 43.106053] attempt to access beyond end of device [ 43.106057] loop0: rw=0, want=277412, limit=277408 [ 43.106061] Buffer I/O error on device loop0, logical block 138705 [ 43.106066] attempt to access beyond end of device [ 43.106070] loop0: rw=0, want=277414, limit=277408 [ 43.106073] Buffer I/O error on device loop0, logical block 138706 [ 43.106078] attempt to access beyond end of device [ 43.106081] loop0: rw=0, want=277416, limit=277408 [ 43.106085] Buffer I/O error on device loop0, logical block 138707 [ 43.106089] attempt to access beyond end of device [ 43.106093] loop0: rw=0, want=277418, limit=277408 [ 43.106096] Buffer I/O error on device loop0, logical block 138708 [ 43.106101] attempt to access beyond end of device [ 43.106104] loop0: rw=0, want=277420, limit=277408 [ 43.106108] Buffer I/O error on device loop0, logical block 138709 [ 43.106112] attempt to access beyond end of device [ 43.106116] loop0: rw=0, want=277422, limit=277408 [ 43.106120] Buffer I/O error on device loop0, logical block 138710 [ 43.106124] attempt to access beyond end of device [ 43.106128] loop0: rw=0, want=277424, limit=277408 [ 43.106131] Buffer I/O error on device loop0, logical block 138711 [ 43.106135] attempt to access beyond end of device [ 43.106139] loop0: rw=0, want=277426, limit=277408 [ 43.106143] Buffer I/O error on device loop0, logical block 138712 [ 43.106147] attempt to access beyond end of device [ 43.106151] loop0: rw=0, want=277428, limit=277408 [ 43.106154] Buffer I/O error on device loop0, logical block 138713 [ 43.106158] attempt to access beyond end of device [ 43.106162] loop0: rw=0, want=277430, limit=277408 [ 43.106166] attempt to access beyond end of device [ 43.106169] loop0: rw=0, want=277432, limit=277408 ... [ 43.106307] attempt to access beyond end of device [ 43.106311] loop0: rw=0, want=277470, limit=2774 Squashfs manages to read in the end block(s) of the disk during the mount operation. Then, when dd reads the block device, it leads to block_read_full_page being called with buffers that are beyond end of disk, but are marked as mapped. Thus, it would end up submitting read I/O against them, resulting in the errors mentioned above. I fixed the problem by modifying init_page_buffers to only set the buffer mapped if it fell inside of i_size. Cheers, Jeff Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Nick Piggin <npiggin@kernel.dk> -- Changes from v1->v2: re-used max_block, as suggested by Nick Piggin. Signed-off-by: Jens Axboe <axboe@kernel.dk>
* magic.h: move some FS magic numbers into magic.hMuthu Kumar2012-03-23
| | | | | | | | | | | - Move open-coded filesystem magic numbers into magic.h - Rearrange magic.h so that the filesystem-related constants are grouped together. Signed-off-by: Muthukumar R <muthur@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'stable/cleancache.v13' into linux-nextKonrad Rzeszutek Wilk2012-03-19
|\ | | | | | | | | | | | | | | * stable/cleancache.v13: mm: cleancache: Use __read_mostly as appropiate. mm: cleancache: report statistics via debugfs instead of sysfs. mm: zcache/tmem/cleancache: s/flush/invalidate/ mm: cleancache: s/flush/invalidate/
| * mm: cleancache: s/flush/invalidate/Dan Magenheimer2012-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per akpm suggestions alter the use of the term flush to be invalidate. The next patch will do this across all MM. This change is completely cosmetic. [v9: akpm@linux-foundation.org: change "flush" to "invalidate", part 3] Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jan Beulich <JBeulich@novell.com> Reviewed-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Chris Mason <chris.mason@oracle.com> Cc: Rik Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> [v10: Fixed fs: move code out of buffer.c conflict change] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | block: Fix NULL pointer dereference in sd_revalidate_diskJun'ichi Nomura2012-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(), __blkdev_get() calls rescan_partitions() to remove in-kernel partition structures and raise KOBJ_CHANGE uevent. However it ends up calling driver's revalidate_disk without open and could cause oops. In the case of SCSI: process A process B ---------------------------------------------- sys_open __blkdev_get sd_open returns -ENOMEDIUM scsi_remove_device <scsi_device torn down> rescan_partitions sd_revalidate_disk <oops> Oopses are reported here: http://marc.info/?l=linux-scsi&m=132388619710052 This patch separates the partition invalidation from rescan_partitions() and use it for -ENOMEDIUM case. Reported-by: Huajun Li <huajun.li.lee@gmail.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | vfs: cache request_queue in struct block_deviceAndi Kleen2012-01-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes it possible to get from the inode to the request_queue with one less cache miss. Used in followon optimization. The livetime of the pointer is the same as the gendisk. This assumes that the queue will always stay the same in the gendisk while it's visible to block_devices. I think that's safe correct? Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | block_dev: Suppress bdev_cache_init() kmemleak warninigSergey Senozhatsky2012-01-10
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kmemleak reports the following warning in bdev_cache_init() [ 0.003738] kmemleak: Object 0xffff880153035200 (size 256): [ 0.003823] kmemleak: comm "swapper/0", pid 0, jiffies 4294667299 [ 0.003909] kmemleak: min_count = 1 [ 0.003988] kmemleak: count = 0 [ 0.004066] kmemleak: flags = 0x1 [ 0.004144] kmemleak: checksum = 0 [ 0.004224] kmemleak: backtrace: [ 0.004303] [<ffffffff814755ac>] kmemleak_alloc+0x21/0x3e [ 0.004446] [<ffffffff811100ba>] kmem_cache_alloc+0xca/0x1dc [ 0.004592] [<ffffffff811371b1>] alloc_vfsmnt+0x1f/0x198 [ 0.004736] [<ffffffff811375c5>] vfs_kern_mount+0x36/0xd2 [ 0.004879] [<ffffffff8113929a>] kern_mount_data+0x18/0x32 [ 0.005025] [<ffffffff81ab9075>] bdev_cache_init+0x51/0x81 [ 0.005169] [<ffffffff81ab8abf>] vfs_caches_init+0x101/0x10d [ 0.005313] [<ffffffff81a9bae3>] start_kernel+0x344/0x383 [ 0.005456] [<ffffffff81a9b2a7>] x86_64_start_reservations+0xae/0xb2 [ 0.005602] [<ffffffff81a9b3ad>] x86_64_start_kernel+0x102/0x111 [ 0.005747] [<ffffffffffffffff>] 0xffffffffffffffff [ 0.008653] kmemleak: Trying to color unknown object at 0xffff880153035220 as Grey [ 0.008754] Pid: 0, comm: swapper/0 Not tainted 3.3.0-rc0-dbg-04200-g8180888-dirty #888 [ 0.008856] Call Trace: [ 0.008934] [<ffffffff81118704>] ? find_and_get_object+0x44/0x118 [ 0.009023] [<ffffffff81118fe6>] paint_ptr+0x57/0x8f [ 0.009109] [<ffffffff81475935>] kmemleak_not_leak+0x23/0x42 [ 0.009195] [<ffffffff81ab9096>] bdev_cache_init+0x72/0x81 [ 0.009282] [<ffffffff81ab8abf>] vfs_caches_init+0x101/0x10d [ 0.009368] [<ffffffff81a9bae3>] start_kernel+0x344/0x383 [ 0.009466] [<ffffffff81a9b2a7>] x86_64_start_reservations+0xae/0xb2 [ 0.009555] [<ffffffff81a9b140>] ? early_idt_handlers+0x140/0x140 [ 0.009643] [<ffffffff81a9b3ad>] x86_64_start_kernel+0x102/0x111 due to attempt to mark pointer to `struct vfsmount' as a gray object, which is embedded into `struct mount' returned from alloc_vfsmnt(). Make `bd_mnt' static, avoiding need to tell kmemleak to mark it gray, as suggested by Al Viro. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: move code out of buffer.cAl Viro2012-01-03
| | | | | | | | | | | | | | | Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: fix the stupidity with i_dentry in inode destructorsAl Viro2012-01-03
| | | | | | | | | | Seeing that just about every destructor got that INIT_LIST_HEAD() copied into it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once(); the cost of taking it into inode_init_always() will be negligible for pipes and sockets and negative for everything else. Not to mention the removal of boilerplate code from ->destroy_inode() instances... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* trim fs/internal.hAl Viro2012-01-03
| | | | | | | some stuff in there can actually become static; some belongs to pnode.h as it's a private interface between namespace.c and pnode.c... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-3.2/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2011-11-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits) virtio-blk: use ida to allocate disk index hpsa: add small delay when using PCI Power Management to reset for kump cciss: add small delay when using PCI Power Management to reset for kump xen/blkback: Fix two races in the handling of barrier requests. xen/blkback: Check for proper operation. xen/blkback: Fix the inhibition to map pages when discarding sector ranges. xen/blkback: Report VBD_WSECT (wr_sect) properly. xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests. xen-blkfront: plug device number leak in xlblk_init() error path xen-blkfront: If no barrier or flush is supported, use invalid operation. xen-blkback: use kzalloc() in favor of kmalloc()+memset() xen-blkback: fixed indentation and comments xen-blkfront: fix a deadlock while handling discard response xen-blkfront: Handle discard requests. xen-blkback: Implement discard requests ('feature-discard') xen-blkfront: add BLKIF_OP_DISCARD and discard request struct drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd() drivers/block/loop.c: emit uevent on auto release drivers/block/cpqarray.c: use pci_dev->revision loop: always allow userspace partitions and optionally support automatic scanning ... Fic up trivial header file includsion conflict in drivers/block/loop.c
| * block: add GENHD_FL_NO_PART_SCANTejun Heo2011-08-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are cases where suppressing partition scan is useful - e.g. for lo devices and pseudo SATA devices which advertise to be a disk but get upset on partition scan (some port multiplier control devices show such behavior). This patch adds GENHD_FL_NO_PART_SCAN which suppresses partition scan regardless of the number of possible partitions. disk_partitionable() is renamed to disk_part_scan_enabled() as suppressing partition scan doesn't imply the device can't be partitioned using BLKPG_ADD/DEL_PARTITION calls from userland. show_partition() now directly tests disk_max_parts() to maintain backward-compatibility. -v2: Updated to make it clear that only partition scan is suppressed not partitioning itself as suggested by Kay Sievers. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | block: make gendisk hold a reference to its queueTejun Heo2011-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following command sequence triggers an oops. # mount /dev/sdb1 /mnt # echo 1 > /sys/class/scsi_device/0\:0\:1\:0/device/delete # umount /mnt general protection fault: 0000 [#1] PREEMPT SMP CPU 2 Modules linked in: Pid: 791, comm: umount Not tainted 3.1.0-rc3-work+ #8 Bochs Bochs RIP: 0010:[<ffffffff810d0879>] [<ffffffff810d0879>] __lock_acquire+0x389/0x1d60 ... Call Trace: [<ffffffff810d2845>] lock_acquire+0x95/0x140 [<ffffffff81aed87b>] _raw_spin_lock+0x3b/0x50 [<ffffffff811573bc>] bdi_lock_two+0x5c/0x70 [<ffffffff811c2f6c>] bdev_inode_switch_bdi+0x4c/0xf0 [<ffffffff811c3fcb>] __blkdev_put+0x11b/0x1d0 [<ffffffff811c4010>] __blkdev_put+0x160/0x1d0 [<ffffffff811c40df>] blkdev_put+0x5f/0x190 [<ffffffff8118f18d>] kill_block_super+0x4d/0x80 [<ffffffff8118f4a5>] deactivate_locked_super+0x45/0x70 [<ffffffff8119003a>] deactivate_super+0x4a/0x70 [<ffffffff811ac4ad>] mntput_no_expire+0xed/0x130 [<ffffffff811acf2e>] sys_umount+0x7e/0x3a0 [<ffffffff81aeeeab>] system_call_fastpath+0x16/0x1b This is because bdev holds on to disk but disk doesn't pin the associated queue. If a SCSI device is removed while the device is still open, the sdev puts the base reference to the queue on release. When the bdev is finally released, the associated queue is already gone along with the bdi and bdev_inode_switch_bdi() ends up dereferencing already freed bdi. Even if it were not for this bug, disk not holding onto the associated queue is very unusual and error-prone. Fix it by making add_disk() take an extra reference to its queue and put it on disk_release() and ensuring that disk and its fops owner are put in that order after all accesses to the disk and queue are complete. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Avoid dereferencing a 'request_queue' after last close.NeilBrown2011-09-10
|/ | | | | | | | | | | | | | | | | | | | | | | | | | 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 <hch@lst.de> Cc: Hugh Dickins <hughd@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
* fix block device fallout from ->fsync() changesRafael J. Wysocki2011-08-01
| | | | | | | blkdev_fsync() needs to write pages in pagecache... Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* block: initialise bd_super in bdget()Lachlan McIlroy2011-08-01
| | | | | | | | | | | | | 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 <lmcilroy@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-07-26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback * '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
| * writeback: split inode_wb_list_lock into bdi_writeback.list_lockChristoph Hellwig2011-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 [<ffffffff81165da5>] bdev_inode_switch_bdi+0x29/0x85 inode_wb_list_lock 34 [<ffffffff8115bd0b>] inode_wb_list_del+0x22/0x49 inode_wb_list_lock 12893 [<ffffffff8115bb53>] __mark_inode_dirty+0x170/0x1d0 inode_wb_list_lock 10702 [<ffffffff8115afef>] writeback_single_inode+0x16d/0x20a ------------------ inode_wb_list_lock 2 [<ffffffff81165da5>] bdev_inode_switch_bdi+0x29/0x85 inode_wb_list_lock 19 [<ffffffff8115bd0b>] inode_wb_list_del+0x22/0x49 inode_wb_list_lock 5550 [<ffffffff8115bb53>] __mark_inode_dirty+0x170/0x1d0 inode_wb_list_lock 8511 [<ffffffff8115b4ad>] 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 [<ffffffff8115b189>] inode_wb_list_del+0x5f/0x86 &(&wb->list_lock)->rlock 1493 [<ffffffff8115b1ed>] writeback_inodes_wb+0x3d/0x150 &(&wb->list_lock)->rlock 3652 [<ffffffff8115a8e9>] writeback_sb_inodes+0x123/0x16f &(&wb->list_lock)->rlock 1412 [<ffffffff8115a38e>] writeback_single_inode+0x17f/0x223 ------------------------ &(&wb->list_lock)->rlock 3 [<ffffffff8110b5af>] bdi_lock_two+0x46/0x4b &(&wb->list_lock)->rlock 6 [<ffffffff8115b189>] inode_wb_list_del+0x5f/0x86 &(&wb->list_lock)->rlock 2061 [<ffffffff8115af97>] __mark_inode_dirty+0x173/0x1cf &(&wb->list_lock)->rlock 2629 [<ffffffff8115a8e9>] 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 <hch@lst.de> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
* | Merge branch 'for-3.1/core' of git://git.kernel.dk/linux-blockLinus Torvalds2011-07-25
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * '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 ...
| * | block: flush MEDIA_CHANGE from drivers on close(2)Tejun Heo2011-07-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlersJosef Bacik2011-07-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <jack@suse.cz> Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseekJosef Bacik2011-07-20
|/ / | | | | | | | | | | | | | | | | | | | | | | 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 <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / block: use the passed in @bdev when claiming if partno is zeroTejun Heo2011-06-13
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <tj@kernel.org> Reported-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Tested-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Cc: stable@kernel.org # >= v2.6.36 Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* block: blkdev_get() should access ->bd_disk only after successTejun Heo2011-06-01
| | | | | | | | | | | | | | | d4dc210f69 (block: don't block events on excl write for non-optical devices) added dereferencing of bdev->bd_disk to test GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE; however, bdev->bd_disk can be %NULL if open failed which can lead to an oops. Test the flag after testing open was successful, not before. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: David Miller <davem@davemloft.net> Tested-by: David Miller <davem@davemloft.net> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* block: move bd_set_size() above rescan_partitions() in __blkdev_get()Tejun Heo2011-05-23
| | | | | | | | | | | | | | | | | | | | | | | | | | 02e352287a4 (block: rescan partitions on invalidated devices on -ENOMEDIA too) relocated partition rescan above explicit bd_set_size() to simplify condition check. As rescan_partitions() does its own bdev size setting, this doesn't break anything; however, rescan_partitions() prints out the following messages when adjusting bdev size, which can be confusing. sda: detected capacity change from 0 to 146815737856 sdb: detected capacity change from 0 to 146815737856 This patch restores the original order and remove the warning messages. stable: Please apply together with 02e352287a4 (block: rescan partitions on invalidated devices on -ENOMEDIA too). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Tony Luck <tony.luck@gmail.com> Tested-by: Tony Luck <tony.luck@gmail.com> Cc: stable@kernel.org Stable note: 2.6.39 only. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* block: don't block events on excl write for non-optical devicesTejun Heo2011-04-21
| | | | | | | | | | | | | | | | | | Disk event code automatically blocks events on excl write. This is primarily to avoid issuing polling commands while burning is in progress. This behavior doesn't fit other types of devices with removeable media where polling commands don't have adverse side effects and door locking usually doesn't exist. This patch introduces new genhd flag which controls the auto-blocking behavior and uses it to enable auto-blocking only on optical devices. Note for stable: 2.6.38 and later only Cc: stable@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* block: rescan partitions on invalidated devices on -ENOMEDIA tooTejun Heo2011-04-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | __blkdev_get() doesn't rescan partitions if disk->fops->open() fails, which leads to ghost partition devices lingering after medimum removal is known to both the kernel and userland. The behavior also creates a subtle inconsistency where O_NONBLOCK open, which doesn't fail even if there's no medium, clears the ghots partitions, which is exploited to work around the problem from userland. Fix it by updating __blkdev_get() to issue partition rescan after -ENOMEDIA too. This was reported in the following bz. https://bugzilla.kernel.org/show_bug.cgi?id=13029 Note for stable: 2.6.38 and later only Cc: stable@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: David Zeuthen <zeuthen@gmail.com> Reported-by: Martin Pitt <martin.pitt@ubuntu.com> Reported-by: Kay Sievers <kay.sievers@vrfy.org> Tested-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* Fix common misspellingsLucas De Marchi2011-03-31
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-03-24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: fs: simplify iget & friends fs: pull inode->i_lock up out of writeback_single_inode fs: rename inode_lock to inode_hash_lock fs: move i_wb_list out from under inode_lock fs: move i_sb_list out from under inode_lock fs: remove inode_lock from iput_final and prune_icache fs: Lock the inode LRU list separately fs: factor inode disposal fs: protect inode->i_state with inode->i_lock autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd() autofs4 - remove autofs4_lock autofs4 - fix d_manage() return on rcu-walk autofs4 - fix autofs4_expire_indirect() traversal autofs4 - fix dentry leak in autofs4_expire_direct() autofs4 - reinstate last used update on access vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
| * fs: move i_wb_list out from under inode_lockDave Chinner2011-03-24
| | | | | | | | | | | | | | | | | | | | | | Protect the inode writeback list with a new global lock inode_wb_list_lock and use it to protect the list manipulations and traversals. This lock replaces the inode_lock as the inodes on the list can be validity checked while holding the inode->i_lock and hence the inode_lock is no longer needed to protect the list. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fs: protect inode->i_state with inode->i_lockDave Chinner2011-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Protect inode state transitions and validity checks with the inode->i_lock. This enables us to make inode state transitions independently of the inode_lock and is the first step to peeling away the inode_lock from the code. This requires that __iget() is done atomically with i_state checks during list traversals so that we don't race with another thread marking the inode I_FREEING between the state check and grabbing the reference. Also remove the unlock_new_inode() memory barrier optimisation required to avoid taking the inode_lock when clearing I_NEW. Simplify the code by simply taking the inode->i_lock around the state change and wakeup. Because the wakeup is no longer tricky, remove the wake_up_inode() function and open code the wakeup where necessary. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | block: NULL dereference on error path in __blkdev_get()Dan Carpenter2011-03-19
| | | | | | | | | | | | | | | | | | | | "disk" is always NULL when we goto out. There was a check for this before, but it was removed in 69e02c59a7d9 "block: Don't check events while open is in progress". Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@carl>
* | Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe2011-03-10
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * | block: remove per-queue pluggingJens Axboe2011-03-10
| | | | | | | | | | | | | | | | | | | | | | | | Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | block: Don't check events while open is in progressTejun Heo2011-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Not all block drivers clear events immediately after reporting. Some do so in ->revalidate_disk() or other steps during ->open(). There is a slim chance event poll may happen between the clearing event check from check_disk_change() and the actual clearing of the events which would result in spurious events. Block event checks while block device open is in progress. There is no need to kick explicit event check afterwards as events are always checked during open. -v2: The original patch could have called disk_unblock_events() with an already released or %NULL @disk causing oops. Fixed by making sure references are put after disk_unblock_events() is called. It also makes the error path of __blkdev_get() a bit simpler. This problem was reported by Jens. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org>
* | | block: Don't check events on close unless it was blockedTejun Heo2011-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The block event mechanism currently always checks events when the device is being closed regardless of the open mode. The intention was to allow detection of EJECT_REQUEST when a device is closed whether disk event polling is enabled or not. This is unnecessary as, for devices of interest, events are checked from either userland or kernel and in the former case ->check_events() is performed on open of each poll attempt anyway. Furthermore, this unconditional event check on close makes the code susceptible to event loop if the block driver doesn't clear reported events correctly - an event triggers userland to open and close the device which in turn causes another event, rinse and repeat. Check events on close only if it was blocked by excl write open. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org>
* | | block: Don't implicitly trigger event check on disk_unblock_events()Tejun Heo2011-03-09
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | Currently, disk_unblock_events() implicitly kick event check if the block count reaches zero. This behavior is not described in the comment and hinders with future changes. Make the unblocker explicitly check events by calling disk_check_events() as necessary. This patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org>
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