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path: root/fs/reiserfs/journal.c
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2010-08-18remove SWRITE* I/O typesChristoph Hellwig
These flags aren't real I/O types, but tell ll_rw_block to always lock the buffer instead of giving up on a failed trylock. Instead add a new write_dirty_buffer helper that implements this semantic and use it from the existing SWRITE* callers. Note that the ll_rw_block code had a bug where it didn't promote WRITE_SYNC_PLUG properly, which this patch fixes. In the ufs code clean up the helper that used to call ll_rw_block to mirror sync_dirty_buffer, which is the function it implements for compound buffers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11reiserfs: remove unused local `wait'Changli Gao
Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24reiserfs: properly honor read-only devicesJeff Mahoney
The reiserfs journal behaves inconsistently when determining whether to allow a mount of a read-only device. This is due to the use of the continue_replay variable to short circuit the journal scanning. If it's set, it's assumed that there are transactions to replay, but there may not be. If it's unset, it's assumed that there aren't any, and that may not be the case either. I've observed two failure cases: 1) Where a clean file system on a read-only device refuses to mount 2) Where a clean file system on a read-only device passes the optimization and then tries writing the journal header to update the latest mount id. The former is easily observable by using a freshly created file system on a read-only loopback device. This patch moves the check into journal_read_transaction, where it can bail out before it's about to replay a transaction. That way it can go through and skip transactions where appropriate, yet still refuse to mount a file system with outstanding transactions. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-28reiserfs: Fix vmalloc call under reiserfs lockFrederic Weisbecker
Vmalloc is called to allocate journal->j_cnode_free_list but we hold the reiserfs lock at this time, which raises a {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} lock inversion. Just drop the reiserfs lock at this time, as it's not even needed but kept for paranoid reasons. This fixes: [ INFO: inconsistent lock state ] 2.6.33-rc5 #1 --------------------------------- inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. kswapd0/313 [HC0[0]:SC0[0]:HE1:SE1] takes: (&REISERFS_SB(s)->lock){+.+.?.}, at: [<c11118c8>] reiserfs_write_lock_once+0x28/0x50 {RECLAIM_FS-ON-W} state was registered at: [<c104ee32>] mark_held_locks+0x62/0x90 [<c104eefa>] lockdep_trace_alloc+0x9a/0xc0 [<c108f7b6>] kmem_cache_alloc+0x26/0xf0 [<c108621c>] __get_vm_area_node+0x6c/0xf0 [<c108690e>] __vmalloc_node+0x7e/0xa0 [<c1086aab>] vmalloc+0x2b/0x30 [<c110e1fb>] journal_init+0x6cb/0xa10 [<c10f90a2>] reiserfs_fill_super+0x342/0xb80 [<c1095665>] get_sb_bdev+0x145/0x180 [<c10f68e1>] get_super_block+0x21/0x30 [<c1094520>] vfs_kern_mount+0x40/0xd0 [<c1094609>] do_kern_mount+0x39/0xd0 [<c10aaa97>] do_mount+0x2c7/0x6d0 [<c10aaf06>] sys_mount+0x66/0xa0 [<c16198a7>] mount_block_root+0xc4/0x245 [<c1619a81>] mount_root+0x59/0x5f [<c1619b98>] prepare_namespace+0x111/0x14b [<c1619269>] kernel_init+0xcf/0xdb [<c100303a>] kernel_thread_helper+0x6/0x1c irq event stamp: 63236801 hardirqs last enabled at (63236801): [<c134e7fa>] __mutex_unlock_slowpath+0x9a/0x120 hardirqs last disabled at (63236800): [<c134e799>] __mutex_unlock_slowpath+0x39/0x120 softirqs last enabled at (63218800): [<c102f451>] __do_softirq+0xc1/0x110 softirqs last disabled at (63218789): [<c102f4ed>] do_softirq+0x4d/0x60 other info that might help us debug this: 2 locks held by kswapd0/313: #0: (shrinker_rwsem){++++..}, at: [<c1074bb4>] shrink_slab+0x24/0x170 #1: (&type->s_umount_key#19){++++..}, at: [<c10a2edd>] shrink_dcache_memory+0xfd/0x1a0 stack backtrace: Pid: 313, comm: kswapd0 Not tainted 2.6.33-rc5 #1 Call Trace: [<c134db2c>] ? printk+0x18/0x1c [<c104e7ef>] print_usage_bug+0x15f/0x1a0 [<c104ebcf>] mark_lock+0x39f/0x5a0 [<c104d66b>] ? trace_hardirqs_off+0xb/0x10 [<c1052c50>] ? check_usage_forwards+0x0/0xf0 [<c1050c24>] __lock_acquire+0x214/0xa70 [<c10438c5>] ? sched_clock_cpu+0x95/0x110 [<c10514fa>] lock_acquire+0x7a/0xa0 [<c11118c8>] ? reiserfs_write_lock_once+0x28/0x50 [<c134f03f>] mutex_lock_nested+0x5f/0x2b0 [<c11118c8>] ? reiserfs_write_lock_once+0x28/0x50 [<c11118c8>] ? reiserfs_write_lock_once+0x28/0x50 [<c11118c8>] reiserfs_write_lock_once+0x28/0x50 [<c10f05b0>] reiserfs_delete_inode+0x50/0x140 [<c10a653f>] ? generic_delete_inode+0x5f/0x150 [<c10f0560>] ? reiserfs_delete_inode+0x0/0x140 [<c10a657c>] generic_delete_inode+0x9c/0x150 [<c10a666d>] generic_drop_inode+0x3d/0x60 [<c10a5597>] iput+0x47/0x50 [<c10a2a4f>] dentry_iput+0x6f/0xf0 [<c10a2af4>] d_kill+0x24/0x50 [<c10a2d3d>] __shrink_dcache_sb+0x21d/0x2b0 [<c10a2f0f>] shrink_dcache_memory+0x12f/0x1a0 [<c1074c9e>] shrink_slab+0x10e/0x170 [<c1075177>] kswapd+0x477/0x6a0 [<c1072d10>] ? isolate_pages_global+0x0/0x1b0 [<c103e160>] ? autoremove_wake_function+0x0/0x40 [<c1074d00>] ? kswapd+0x0/0x6a0 [<c103de6c>] kthread+0x6c/0x80 [<c103de00>] ? kthread+0x0/0x80 [<c100303a>] kernel_thread_helper+0x6/0x1c Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Chris Mason <chris.mason@oracle.com>
2010-01-02reiserfs: Relax reiserfs lock while freeing the journalFrederic Weisbecker
Keeping the reiserfs lock while freeing the journal on umount path triggers a lock inversion between bdev->bd_mutex and the reiserfs lock. We don't need the reiserfs lock at this stage. The filesystem is not usable anymore, and there are no more pending commits, everything got flushed (even this operation was done in parallel and didn't required the reiserfs lock from the current process). This fixes the following lockdep report: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #172 ------------------------------------------------------- umount/3904 is trying to acquire lock: (&bdev->bd_mutex){+.+.+.}, at: [<c10de2c2>] __blkdev_put+0x22/0x160 but task is already holding lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143279>] reiserfs_write_lock+0x29/0x40 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&REISERFS_SB(s)->lock){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c1143229>] reiserfs_write_lock_once+0x29/0x50 [<c111c485>] reiserfs_get_block+0x85/0x1620 [<c10e1040>] do_mpage_readpage+0x1f0/0x6d0 [<c10e1640>] mpage_readpages+0xc0/0x100 [<c1119b89>] reiserfs_readpages+0x19/0x20 [<c108f1ec>] __do_page_cache_readahead+0x1bc/0x260 [<c108f2b8>] ra_submit+0x28/0x40 [<c1087e3e>] filemap_fault+0x40e/0x420 [<c109b5fd>] __do_fault+0x3d/0x430 [<c109d47e>] handle_mm_fault+0x12e/0x790 [<c1022a65>] do_page_fault+0x135/0x330 [<c1403663>] error_code+0x6b/0x70 [<c10ef9ca>] load_elf_binary+0x82a/0x1a10 [<c10ba130>] search_binary_handler+0x90/0x1d0 [<c10bb70f>] do_execve+0x1df/0x250 [<c1001746>] sys_execve+0x46/0x70 [<c1002fa5>] syscall_call+0x7/0xb -> #2 (&mm->mmap_sem){++++++}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c109b1ab>] might_fault+0x8b/0xb0 [<c11b8f52>] copy_to_user+0x32/0x70 [<c10c3b94>] filldir64+0xa4/0xf0 [<c1109116>] sysfs_readdir+0x116/0x210 [<c10c3e1d>] vfs_readdir+0x8d/0xb0 [<c10c3ea9>] sys_getdents64+0x69/0xb0 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #1 (sysfs_mutex){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c110951c>] sysfs_addrm_start+0x2c/0xb0 [<c1109aa0>] create_dir+0x40/0x90 [<c1109b1b>] sysfs_create_dir+0x2b/0x50 [<c11b2352>] kobject_add_internal+0xc2/0x1b0 [<c11b2531>] kobject_add_varg+0x31/0x50 [<c11b25ac>] kobject_add+0x2c/0x60 [<c1258294>] device_add+0x94/0x560 [<c11036ea>] add_partition+0x18a/0x2a0 [<c110418a>] rescan_partitions+0x33a/0x450 [<c10de5bf>] __blkdev_get+0x12f/0x2d0 [<c10de76a>] blkdev_get+0xa/0x10 [<c11034b8>] register_disk+0x108/0x130 [<c11a87a9>] add_disk+0xd9/0x130 [<c12998e5>] sd_probe_async+0x105/0x1d0 [<c10528af>] async_thread+0xcf/0x230 [<c104bfd4>] kthread+0x74/0x80 [<c1003aab>] kernel_thread_helper+0x7/0x3c -> #0 (&bdev->bd_mutex){+.+.+.}: [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c10de2c2>] __blkdev_put+0x22/0x160 [<c10de40a>] blkdev_put+0xa/0x10 [<c113ce22>] free_journal_ram+0xd2/0x130 [<c113ea18>] do_journal_release+0x98/0x190 [<c113eb2a>] journal_release+0xa/0x10 [<c1128eb6>] reiserfs_put_super+0x36/0x130 [<c10b776f>] generic_shutdown_super+0x4f/0xe0 [<c10b7825>] kill_block_super+0x25/0x40 [<c11255df>] reiserfs_kill_sb+0x7f/0x90 [<c10b7f4a>] deactivate_super+0x7a/0x90 [<c10cccd8>] mntput_no_expire+0x98/0xd0 [<c10ccfcc>] sys_umount+0x4c/0x310 [<c10cd2a9>] sys_oldumount+0x19/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 other info that might help us debug this: 2 locks held by umount/3904: #0: (&type->s_umount_key#30){+++++.}, at: [<c10b7f45>] deactivate_super+0x75/0x90 #1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143279>] reiserfs_write_lock+0x29/0x40 stack backtrace: Pid: 3904, comm: umount Not tainted 2.6.32-atom #172 Call Trace: [<c13ff903>] ? printk+0x18/0x1a [<c105d33a>] print_circular_bug+0xca/0xd0 [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c108b66f>] ? free_pcppages_bulk+0x1f/0x250 [<c105f2c8>] lock_acquire+0x68/0x90 [<c10de2c2>] ? __blkdev_put+0x22/0x160 [<c10de2c2>] ? __blkdev_put+0x22/0x160 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c10de2c2>] ? __blkdev_put+0x22/0x160 [<c105c932>] ? mark_held_locks+0x62/0x80 [<c10afe12>] ? kfree+0x92/0xd0 [<c10de2c2>] __blkdev_put+0x22/0x160 [<c105cc3b>] ? trace_hardirqs_on+0xb/0x10 [<c10de40a>] blkdev_put+0xa/0x10 [<c113ce22>] free_journal_ram+0xd2/0x130 [<c113ea18>] do_journal_release+0x98/0x190 [<c113eb2a>] journal_release+0xa/0x10 [<c1128eb6>] reiserfs_put_super+0x36/0x130 [<c1050596>] ? up_write+0x16/0x30 [<c10b776f>] generic_shutdown_super+0x4f/0xe0 [<c10b7825>] kill_block_super+0x25/0x40 [<c10f41e0>] ? vfs_quota_off+0x0/0x20 [<c11255df>] reiserfs_kill_sb+0x7f/0x90 [<c10b7f4a>] deactivate_super+0x7a/0x90 [<c10cccd8>] mntput_no_expire+0x98/0xd0 [<c10ccfcc>] sys_umount+0x4c/0x310 [<c10cd2a9>] sys_oldumount+0x19/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-29reiserfs: Fix remaining in-reclaim-fs <-> reclaim-fs-on locking inversionFrederic Weisbecker
Commit 500f5a0bf5f0624dae34307010e240ec090e4cde (reiserfs: Fix possible recursive lock) fixed a vmalloc under reiserfs lock that triggered a lockdep warning because of a IN-FS-RECLAIM <-> RECLAIM-FS-ON locking dependency inversion. But this patch has ommitted another vmalloc call in the same path that allocates the journal. Relax the lock for this one too. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2009-10-05kill-the-bkl/reiserfs: fix reiserfs lock to cpu_add_remove_lock dependencyFrederic Weisbecker
While creating the reiserfs workqueue during the journal initialization, we are holding the reiserfs lock, but create_workqueue() also holds the cpu_add_remove_lock, creating then the following dependency: - reiserfs lock -> cpu_add_remove_lock But we also have the following existing dependencies: - mm->mmap_sem -> reiserfs lock - cpu_add_remove_lock -> cpu_hotplug.lock -> slub_lock -> sysfs_mutex The merged dependency chain then becomes: - mm->mmap_sem -> reiserfs lock -> cpu_add_remove_lock -> cpu_hotplug.lock -> slub_lock -> sysfs_mutex But when we fill a dir entry in sysfs_readir(), we are holding the sysfs_mutex and we also might fault while copying the directory entry to the user, leading to the following dependency: - sysfs_mutex -> mm->mmap_sem The end result is then a lock inversion between sysfs_mutex and mm->mmap_sem, as reported in the following lockdep warning: [ INFO: possible circular locking dependency detected ] 2.6.31-07095-g25a3912 #4 ------------------------------------------------------- udevadm/790 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<c1098942>] might_fault+0x72/0xc0 but task is already holding lock: (sysfs_mutex){+.+.+.}, at: [<c110813c>] sysfs_readdir+0x7c/0x260 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (sysfs_mutex){+.+.+.}: [...] -> #4 (slub_lock){+++++.}: [...] -> #3 (cpu_hotplug.lock){+.+.+.}: [...] -> #2 (cpu_add_remove_lock){+.+.+.}: [...] -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [...] -> #0 (&mm->mmap_sem){++++++}: [...] This can be fixed by relaxing the reiserfs lock while creating the workqueue. This is fine to relax the lock here, we just keep it around to pass through reiserfs lock checks and for paranoid reasons. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Tested-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-17kill-the-bkl/reiserfs: Fix induced mm->mmap_sem to sysfs_mutex dependencyFrederic Weisbecker
Alexander Beregalov reported the following warning: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.31-03149-gdcc030a #1 ------------------------------------------------------- udevadm/716 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<c107249a>] might_fault+0x4a/0xa0 but task is already holding lock: (sysfs_mutex){+.+.+.}, at: [<c10cb9aa>] sysfs_readdir+0x5a/0x200 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sysfs_mutex){+.+.+.}: [...] -> #2 (&bdev->bd_mutex){+.+.+.}: [...] -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [...] -> #0 (&mm->mmap_sem){++++++}: [...] On reiserfs mount path, we take the reiserfs lock and while initializing the journal, we open the device, taking the bdev->bd_mutex. Then rescan_partition() may signal the change to sysfs. We have then the following dependency: reiserfs_lock -> bd_mutex -> sysfs_mutex Later, while entering reiserfs_readpage() after a pagefault in an mmaped reiserfs file, we are holding the mm->mmap_sem, and we are going to take the reiserfs lock too. We have then the following dependency: mm->mmap_sem -> reiserfs_lock which, expanded with the previous dependency gives us: mm->mmap_sem -> reiserfs_lock -> bd_mutex -> sysfs_mutex Now while entering the sysfs readdir path, we are holding the sysfs_mutex. And when we copy a directory entry to the user buffer, we might fault and then take the mm->mmap_sem lock. Which leads to the circular locking dependency reported. We can fix that by relaxing the reiserfs lock during the call to journal_init_dev(), which is the place where we open the mounted device. This is fine to relax the lock here because we are in the begining of the reiserfs mount path and there is nothing to protect at this time, the journal is not intialized. We just keep this lock around for paranoid reasons. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Tested-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14kill-the-bkl/reiserfs: acquire the inode mutex safelyFrederic Weisbecker
While searching a pathname, an inode mutex can be acquired in do_lookup() which calls reiserfs_lookup() which in turn acquires the write lock. On the other side reiserfs_fill_super() can acquire the write_lock and then call reiserfs_lookup_privroot() which can acquire an inode mutex (the root of the mount point). So we theoretically risk an AB - BA lock inversion that could lead to a deadlock. As for other lock dependencies found since the bkl to mutex conversion, the fix is to use reiserfs_mutex_lock_safe() which drops the lock dependency to the write lock. [ Impact: fix a possible deadlock with reiserfs ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-bkl/reiserfs: use mutex_lock in reiserfs_mutex_lock_safeFrederic Weisbecker
reiserfs_mutex_lock_safe() is a hack to avoid any dependency between an internal reiserfs mutex and the write lock, it has been proposed to follow the old bkl logic. The code does the following: while (!mutex_trylock(m)) { reiserfs_write_unlock(s); schedule(); reiserfs_write_lock(s); } It then imitate the implicit behaviour of the lock when it was a Bkl and hadn't such dependency: mutex_lock(m) { if (fastpath) let's go else { wait_for_mutex() { schedule() { unlock_kernel() reacquire_lock_kernel() } } } } The problem is that by using such explicit schedule(), we don't benefit of the adaptive mutex spinning on owner. The logic in use now is: reiserfs_write_unlock(s); mutex_lock(m); // -> possible adaptive spinning reiserfs_write_lock(s); [ Impact: restore the use of adaptive spinning mutexes in reiserfs ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-BKL/reiserfs: release the write lock on flush_commit_list()Frederic Weisbecker
flush_commit_list() uses ll_rw_block() to commit the pending log blocks. ll_rw_block() might sleep, and the bkl was released at this point. Then we can also relax the write lock at this point. [ Impact: release the reiserfs write lock when it is not needed ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-BKL/reiserfs: release the write lock before rescheduling on ↵Frederic Weisbecker
do_journal_end() When do_journal_end() copies data to the journal blocks buffers in memory, it reschedules if needed between each block copied and dirtyfied. We can also release the write lock at this rescheduling stage, like did the bkl implicitly. [ Impact: release the reiserfs write lock when it is not needed ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14reiserfs, kill-the-BKL: fix unsafe j_flush_mutex lockFrederic Weisbecker
Impact: fix a deadlock The j_flush_mutex is acquired safely in journal.c: if we can't take it, we free the reiserfs per superblock lock and wait a bit. But we have a remaining place in kupdate_transactions() where j_flush_mutex is still acquired traditionnaly. Thus the following scenario (warned by lockdep) can happen: A B mutex_lock(&write_lock) mutex_lock(&write_lock) mutex_lock(&j_flush_mutex) mutex_lock(&j_flush_mutex) //block mutex_unlock(&write_lock) sleep... mutex_lock(&write_lock) //deadlock Fix this by using reiserfs_mutex_lock_safe() in kupdate_transactions(). Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@texware.it> Cc: Jeff Mahoney <jeffm@suse.com> LKML-Reference: <1239660635-12940-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14reiserfs: kill-the-BKLFrederic Weisbecker
This patch is an attempt to remove the Bkl based locking scheme from reiserfs and is intended. It is a bit inspired from an old attempt by Peter Zijlstra: http://lkml.indiana.edu/hypermail/linux/kernel/0704.2/2174.html The bkl is heavily used in this filesystem to prevent from concurrent write accesses on the filesystem. Reiserfs makes a deep use of the specific properties of the Bkl: - It can be acqquired recursively by a same task - It is released on the schedule() calls and reacquired when schedule() returns The two properties above are a roadmap for the reiserfs write locking so it's very hard to simply replace it with a common mutex. - We need a recursive-able locking unless we want to restructure several blocks of the code. - We need to identify the sites where the bkl was implictly relaxed (schedule, wait, sync, etc...) so that we can in turn release and reacquire our new lock explicitly. Such implicit releases of the lock are often required to let other resources producer/consumer do their job or we can suffer unexpected starvations or deadlocks. So the new lock that replaces the bkl here is a per superblock mutex with a specific property: it can be acquired recursively by a same task, like the bkl. For such purpose, we integrate a lock owner and a lock depth field on the superblock information structure. The first axis on this patch is to turn reiserfs_write_(un)lock() function into a wrapper to manage this mutex. Also some explicit calls to lock_kernel() have been converted to reiserfs_write_lock() helpers. The second axis is to find the important blocking sites (schedule...(), wait_on_buffer(), sync_dirty_buffer(), etc...) and then apply an explicit release of the write lock on these locations before blocking. Then we can safely wait for those who can give us resources or those who need some. Typically this is a fight between the current writer, the reiserfs workqueue (aka the async commiter) and the pdflush threads. The third axis is a consequence of the second. The write lock is usually on top of a lock dependency chain which can include the journal lock, the flush lock or the commit lock. So it's dangerous to release and trying to reacquire the write lock while we still hold other locks. This is fine with the bkl: T1 T2 lock_kernel() mutex_lock(A) unlock_kernel() // do something lock_kernel() mutex_lock(A) -> already locked by T1 schedule() (and then unlock_kernel()) lock_kernel() mutex_unlock(A) .... This is not fine with a mutex: T1 T2 mutex_lock(write) mutex_lock(A) mutex_unlock(write) // do something mutex_lock(write) mutex_lock(A) -> already locked by T1 schedule() mutex_lock(write) -> already locked by T2 deadlock The solution in this patch is to provide a helper which releases the write lock and sleep a bit if we can't lock a mutex that depend on it. It's another simulation of the bkl behaviour. The last axis is to locate the fs callbacks that are called with the bkl held, according to Documentation/filesystem/Locking. Those are: - reiserfs_remount - reiserfs_fill_super - reiserfs_put_super Reiserfs didn't need to explicitly lock because of the context of these callbacks. But now we must take care of that with the new locking. After this patch, reiserfs suffers from a slight performance regression (for now). On UP, a high volume write with dd reports an average of 27 MB/s instead of 30 MB/s without the patch applied. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Bron Gondwana <brong@fastmail.fm> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> LKML-Reference: <1239070789-13354-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10Fix congestion_wait() sync/async vs read/write confusionJens Axboe
Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke the bdi congestion wait queue logic, causing us to wait on congestion for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-30reiserfs: rename p_s_sb to sbJeff Mahoney
This patch is a simple s/p_s_sb/sb/g to the reiserfs code. This is the first in a series of patches to rip out some of the awful variable naming in reiserfs. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30reiserfs: strip trailing whitespaceJeff Mahoney
This patch strips trailing whitespace from the reiserfs code. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30reiserfs: rearrange journal abortJeff Mahoney
This patch kills off reiserfs_journal_abort as it is never called, and combines __reiserfs_journal_abort_{soft,hard} into one function called reiserfs_abort_journal, which performs the same work. It is silent as opposed to the old version, since the message was always issued after a regular 'abort' message. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30reiserfs: rework reiserfs_panicJeff Mahoney
ReiserFS panics can be somewhat inconsistent. In some cases: * a unique identifier may be associated with it * the function name may be included * the device may be printed separately This patch aims to make warnings more consistent. reiserfs_warning() prints the device name, so printing it a second time is not required. The function name for a warning is always helpful in debugging, so it is now automatically inserted into the output. Hans has stated that every warning should have a unique identifier. Some cases lack them, others really shouldn't have them. reiserfs_warning() now expects an id associated with each message. In the rare case where one isn't needed, "" will suffice. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30reiserfs: rework reiserfs_warningJeff Mahoney
ReiserFS warnings can be somewhat inconsistent. In some cases: * a unique identifier may be associated with it * the function name may be included * the device may be printed separately This patch aims to make warnings more consistent. reiserfs_warning() prints the device name, so printing it a second time is not required. The function name for a warning is always helpful in debugging, so it is now automatically inserted into the output. Hans has stated that every warning should have a unique identifier. Some cases lack them, others really shouldn't have them. reiserfs_warning() now expects an id associated with each message. In the rare case where one isn't needed, "" will suffice. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30reiserfs: audit transaction ids to always be unsigned intsJeff Mahoney
This patch fixes up the reiserfs code such that transaction ids are always unsigned ints. In places they can currently be signed ints or unsigned longs. The former just causes an annoying clm-2200 warning and may join a transaction when it should wait. The latter is just for correctness since the disk format uses a 32-bit transaction id. There aren't any runtime problems that result from it not wrapping at the correct location since the value is truncated correctly even on big endian systems. The 0 value might make it to disk, but the mount-time checks will bump it to 10 itself. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-21[PATCH] remember mode of reiserfs journalAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] propagate mode through open_bdev_excl/close_bdev_exclAl Viro
replace open_bdev_excl/close_bdev_excl with variants taking fmode_t. superblock gets the value used to mount it stored in sb->s_mode Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] pass fmode_t to blkdev_put()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] introduce fmode_t, do annotationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-05fs: rename buffer trylockNick Piggin
Like the page lock change, this also requires name change, so convert the raw test_and_set bitop to a trylock. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-05mm: rename page trylockNick Piggin
Converting page lock to new locking bitops requires a change of page flag operation naming, so we might as well convert it to something nicer (!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked). This also facilitates lockdeping of page lock. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25reiserfs: convert j_commit_lock to mutexJeff Mahoney
j_commit_lock is a semaphore but uses it as if it were a mutex. This patch converts it to a mutex. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Chris Mason <chris.mason@oracle.com> Cc: Edward Shishkin <edward.shishkin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25reiserfs: convert j_flush_sem to mutexJeff Mahoney
j_flush_sem is a semaphore but uses it as if it were a mutex. This patch converts it to a mutex. [akpm@linux-foundation.org: fix mutex_trylock retval treatment] Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Chris Mason <chris.mason@oracle.com> Cc: Edward Shishkin <edward.shishkin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25reiserfs: convert j_lock to mutexJeff Mahoney
j_lock is a semaphore but uses it as if it were a mutex. This patch converts it to a mutex. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Chris Mason <chris.mason@oracle.com> Cc: Edward Shishkin <edward.shishkin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30reiserfs: use open_bdev_exclChristoph Hellwig
Use the proper helper to open a blockdevice by name for filesystem use, this makes sure it's properly claimed (also added for open-by-number) and gets rid of the struct file abuse. Tested by mounting a reiserfs filesystem with external journal. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jeff Mahoney <jeffm@suse.com> Acked-by: Edward Shishkin <edward.shishkin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28reiserfs: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28reiserfs: fix sparse warning in journal.cHarvey Harrison
fs/reiserfs/journal.c:4319:2: warning: returning void-valued expression Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-19Convert asm/semaphore.h users to linux/semaphore.hMatthew Wilcox
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-10-19reiserfs: ignore on disk s_bmap_nr valueJeff Mahoney
Implement support for file systems larger than 8 TiB. The reiserfs superblock contains a 16 bit value for counting the number of bitmap blocks. The rest of the disk format supports file systems up to 2^32 blocks, but the bitmap block limitation artificially limits this to 8 TiB with a 4KiB block size. Rather than trust the superblock's 16-bit bitmap block count, we calculate it dynamically based on the number of blocks in the file system. When an incorrect value is observed in the superblock, it is zeroed out, ensuring that older kernels will not be able to mount the file system. Userspace support has already been implemented and shipped in reiserfsprogs 3.6.20. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19reiserfs: fix usage of signed ints for block numbersJeff Mahoney
Do a quick signedness check for block numbers. There are a number of places where signed integers are used for block numbers, which limits the usable file system size to 8 TiB. The disk format, excepting a problem which will be fixed in the following patch, supports file systems up to 16 TiB in size. This patch cleans up those sites so that we can enable the full usable size. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17reiserfs: do not repair wrong journal paramsEdward Shishkin
When mounting a file system with wrong journal params do not try to repair them, suggest fsck instead. Signed-off-by: Edward Shishkin <edward@namesys.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17try to reap reiserfs pages left around by invalidatepageChris Mason
reiserfs_invalidatepage will refuse to free pages if they have been logged in data=journal mode, or were pinned down by a data=ordered operation. For data=journal, this is fairly easy to trigger just with fsx-linux, and it results in a large number of pages hanging around on the LRUs with page->mapping == NULL. Calling try_to_free_buffers when reiserfs decides it is done with the page allows it to be freed earlier, and with much less VM thrashing. Lock ordering rules mean that reiserfs can't call lock_page when it is releasing the buffers, so TestSetPageLocked is used instead. Contention on these pages should be rare, so it should be sufficient most of the time. Signed-off-by: Chris Mason <chris.mason@oracle.com> Cc: "Vladimir V. Saveliev" <vs@namesys.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17fs/reiserfs/: cleanupsAdrian Bunk
- remove the following no longer used functions: - bitmap.c: reiserfs_claim_blocks_to_be_allocated() - bitmap.c: reiserfs_release_claimed_blocks() - bitmap.c: reiserfs_can_fit_pages() - make the following functions static: - inode.c: restart_transaction() - journal.c: reiserfs_async_progress_wait() Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Vladimir V. Saveliev <vs@namesys.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Fix misspellings collected by members of KJ list.Robert P. J. Day
Fix the misspellings of "propogate", "writting" and (oh, the shame :-) "kenrel" in the source tree. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-08reiserfs: use __set_current_state()Milind Arun Choudhary
use __set_current_state(TASK_*) instead of current->state = TASK_*, in fs/reiserfs Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Cc: <reiserfs-dev@namesys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-05Merge branch 'master' of ↵David Howells
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: drivers/infiniband/core/iwcm.c drivers/net/chelsio/cxgb2.c drivers/net/wireless/bcm43xx/bcm43xx_main.c drivers/net/wireless/prism54/islpci_eth.c drivers/usb/core/hub.h drivers/usb/input/hid-core.c net/core/netpoll.c Fix up merge failures with Linus's head and fix new compilation failures. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-30Fix misc .c/.h comment typosMatt LaPlante
Fix various .c/.h typos in comments (no code changes). Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-11-22WorkStruct: make allyesconfigDavid Howells
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-20[PATCH] separate bdi congestion functions from queue congestion functionsAndrew Morton
Separate out the concept of "queue congestion" from "backing-dev congestion". Congestion is a backing-dev concept, not a queue concept. The blk_* congestion functions are retained, as wrappers around the core backing-dev congestion functions. This proper layering is needed so that NFS can cleanly use the congestion functions, and so that CONFIG_BLOCK=n actually links. Cc: "Thomas Maier" <balagi@justmail.de> Cc: "Jens Axboe" <jens.axboe@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: David Howells <dhowells@redhat.com> Cc: Peter Osterlund <petero2@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03BUG_ON conversion for fs/reiserfsEric Sesterhenn
This patch converts several if () BUG(); construct to BUG_ON(); which occupies less space, uses unlikely and is safer when BUG() is disabled. S_ISREG() has no side effects, so the conversion is safe. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-09-29[PATCH] Fix reiserfs latencies caused by data=orderedChris Mason
ReiserFS does periodic cleanup of old transactions in order to limit the length of time a journal replay may take after a crash. Sometimes, writing metadata from an old (already committed) transaction may require committing a newer transaction, which also requires writing all data=ordered buffers. This can cause very long stalls on journal_begin. This patch makes sure new transactions will not need to be committed before trying a periodic reclaim of an old transaction. It is low risk because if a bad decision is made, it just means a slightly longer journal replay after a crash. Signed-off-by: Chris Mason <mason@suse.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26[PATCH] fs: use list_move()Akinobu Mita
This patch converts the combination of list_del(A) and list_add(A, B) to list_move(A, B) under fs/. Cc: Ian Kent <raven@themaw.net> Acked-by: Joel Becker <joel.becker@oracle.com> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: Hans Reiser <reiserfs-dev@namesys.com> Cc: Urban Widmark <urban@teststation.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>