05 Jan, 2010
4 commits
-
Holding locks over device_del -> kobject_del -> sysfs_deactivate can
cause deadlocks if those same locks are grabbed in sysfs show or store
methods.The I model s_active count + completion as a sleeping read/write lock.
I describe to lockdep sysfs_get_active as a read_trylock,
sysfs_put_active as a read_unlock, and sysfs_deactivate as a
write_lock and write_unlock pair. This seems to capture the essence
for purposes of finding deadlocks, and in my testing gives finds real
issues and ignores non-issues.This brings us back to holding locks over kobject_del is a problem
that ideally we should find a way of addressing, but at least lockdep
can tell us about the problems instead of requiring developers to debug
rare strange system deadlocks, that happen when sysfs files are removed
while being written to.Signed-off-by: Eric W. Biederman
Acked-by: Tejun Heo
Signed-off-by: Linus Torvalds -
* 'sh/for-2.6.33' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
binfmt_elf_fdpic: Fix build breakage introduced by coredump changes.
sh: update defconfigs.
sh: Don't default enable PMB support.
sh: Disable PMB for SH4AL-DSP CPUs.
sh: Only provide a PCLK definition for legacy CPG CPUs. -
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Calculate metadata requirements more accurately
ext4: Fix accounting of reserved metadata blocks -
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
nilfs2: update mailing list address
nilfs2: Storage class should be before const qualifier
nilfs2: trivial coding style fix
04 Jan, 2010
1 commit
-
Commit f6151dfea21496d43dbaba32cfcd9c9f404769bc introduces build
breakage, so this patch fixes it together with some printk formatting
cleanup.Signed-off-by: Daisuke HATAYAMA
Signed-off-by: Paul Mundt
03 Jan, 2010
2 commits
-
…t/frederic/random-tracing
* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
reiserfs: Safely acquire i_mutex from xattr_rmdir
reiserfs: Safely acquire i_mutex from reiserfs_for_each_xattr
reiserfs: Fix journal mutex <-> inode mutex lock inversion
reiserfs: Fix unwanted recursive reiserfs lock in reiserfs_unlink()
reiserfs: Relax lock before open xattr dir in reiserfs_xattr_set_handle()
reiserfs: Relax reiserfs lock while freeing the journal
reiserfs: Fix reiserfs lock <-> i_mutex dependency inversion on xattr
reiserfs: Warn on lock relax if taken recursively
reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversion
reiserfs: Fix remaining in-reclaim-fs <-> reclaim-fs-on locking inversion
reiserfs: Fix reiserfs lock <-> inode mutex dependency inversion
reiserfs: Fix reiserfs lock and journal lock inversion dependency
reiserfs: Fix possible recursive lock -
Fix the following htmldocs warning:
Warning(fs/fs-writeback.c:255): No description found for parameter 'sb'
Signed-off-by: Jaswinder Singh Rajput
Signed-off-by: Randy Dunlap
Acked-by: Wu Fengguang
Cc: Peter Zijlstra
Cc: Jan Kara
Cc: Jens Axboe
Signed-off-by: Linus Torvalds
02 Jan, 2010
9 commits
-
Relax the reiserfs lock before taking the inode mutex from
xattr_rmdir() to avoid the usual reiserfs lock inode mutex
bad dependency.Signed-off-by: Frederic Weisbecker
Tested-by: Christian Kujau
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
Relax the reiserfs lock before taking the inode mutex from
reiserfs_for_each_xattr() to avoid the usual bad dependencies:=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #179
-------------------------------------------------------
rm/3242 is trying to acquire lock:
(&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [] reiserfs_for_each_xattr+0x23f/0x290but task is already holding lock:
(&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x29/0x40which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&REISERFS_SB(s)->lock){+.+.+.}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] reiserfs_write_lock_once+0x29/0x50
[] reiserfs_lookup+0x62/0x140
[] __lookup_hash+0xef/0x110
[] lookup_one_len+0x8d/0xc0
[] open_xa_dir+0xea/0x1b0
[] reiserfs_for_each_xattr+0x70/0x290
[] reiserfs_delete_xattrs+0x1a/0x60
[] reiserfs_delete_inode+0x9f/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] sys_unlinkat+0x23/0x40
[] sysenter_do_call+0x12/0x32-> #0 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
[] __lock_acquire+0x18f6/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] reiserfs_for_each_xattr+0x23f/0x290
[] reiserfs_delete_xattrs+0x1a/0x60
[] reiserfs_delete_inode+0x9f/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] sys_unlinkat+0x23/0x40
[] sysenter_do_call+0x12/0x32other info that might help us debug this:
1 lock held by rm/3242:
#0: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x29/0x40stack backtrace:
Pid: 3242, comm: rm Not tainted 2.6.32-atom #179
Call Trace:
[] ? printk+0x18/0x1a
[] print_circular_bug+0xca/0xd0
[] __lock_acquire+0x18f6/0x19e0
[] ? mark_held_locks+0x62/0x80
[] ? trace_hardirqs_on+0xb/0x10
[] ? mutex_unlock+0x8/0x10
[] lock_acquire+0x68/0x90
[] ? reiserfs_for_each_xattr+0x23f/0x290
[] ? reiserfs_for_each_xattr+0x23f/0x290
[] mutex_lock_nested+0x5b/0x340
[] ? reiserfs_for_each_xattr+0x23f/0x290
[] reiserfs_for_each_xattr+0x23f/0x290
[] ? delete_one_xattr+0x0/0x100
[] reiserfs_delete_xattrs+0x1a/0x60
[] ? reiserfs_write_lock_once+0x29/0x50
[] reiserfs_delete_inode+0x9f/0x150
[] ? _atomic_dec_and_lock+0x4f/0x70
[] ? reiserfs_delete_inode+0x0/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] ? mutex_unlock+0x8/0x10
[] ? vfs_readdir+0x7d/0xb0
[] ? filldir64+0x0/0xf0
[] ? sysenter_exit+0xf/0x16
[] ? trace_hardirqs_on_caller+0x124/0x170
[] sys_unlinkat+0x23/0x40
[] sysenter_do_call+0x12/0x32Signed-off-by: Frederic Weisbecker
Tested-by: Christian Kujau
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
We need to relax the reiserfs lock before locking the inode mutex
from xattr_unlink(), otherwise we'll face the usual bad dependencies:=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #178
-------------------------------------------------------
rm/3202 is trying to acquire lock:
(&journal->j_mutex){+.+...}, at: [] do_journal_begin_r+0x94/0x360but task is already holding lock:
(&sb->s_type->i_mutex_key#4/2){+.+...}, at: [] xattr_unlink+0x57/0xb0which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&sb->s_type->i_mutex_key#4/2){+.+...}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] xattr_unlink+0x57/0xb0
[] delete_one_xattr+0x29/0x100
[] reiserfs_for_each_xattr+0x10b/0x290
[] reiserfs_delete_xattrs+0x1a/0x60
[] reiserfs_delete_inode+0x9f/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] sys_unlinkat+0x23/0x40
[] sysenter_do_call+0x12/0x32-> #1 (&REISERFS_SB(s)->lock){+.+.+.}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] reiserfs_write_lock+0x29/0x40
[] do_journal_begin_r+0x9c/0x360
[] journal_begin+0x80/0x130
[] reiserfs_remount+0x223/0x4e0
[] do_remount_sb+0xa6/0x140
[] do_mount+0x560/0x750
[] sys_mount+0x84/0xb0
[] sysenter_do_call+0x12/0x32-> #0 (&journal->j_mutex){+.+...}:
[] __lock_acquire+0x18f6/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] do_journal_begin_r+0x94/0x360
[] journal_begin+0x80/0x130
[] reiserfs_unlink+0x83/0x2e0
[] xattr_unlink+0x64/0xb0
[] delete_one_xattr+0x29/0x100
[] reiserfs_for_each_xattr+0x10b/0x290
[] reiserfs_delete_xattrs+0x1a/0x60
[] reiserfs_delete_inode+0x9f/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] sys_unlinkat+0x23/0x40
[] sysenter_do_call+0x12/0x32other info that might help us debug this:
2 locks held by rm/3202:
#0: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [] reiserfs_for_each_xattr+0x9b/0x290
#1: (&sb->s_type->i_mutex_key#4/2){+.+...}, at: [] xattr_unlink+0x57/0xb0stack backtrace:
Pid: 3202, comm: rm Not tainted 2.6.32-atom #178
Call Trace:
[] ? printk+0x18/0x1a
[] print_circular_bug+0xca/0xd0
[] __lock_acquire+0x18f6/0x19e0
[] ? xattr_unlink+0x57/0xb0
[] lock_acquire+0x68/0x90
[] ? do_journal_begin_r+0x94/0x360
[] ? do_journal_begin_r+0x94/0x360
[] mutex_lock_nested+0x5b/0x340
[] ? do_journal_begin_r+0x94/0x360
[] do_journal_begin_r+0x94/0x360
[] ? run_timer_softirq+0x1a6/0x220
[] ? __do_softirq+0x50/0x140
[] journal_begin+0x80/0x130
[] ? __do_softirq+0xf2/0x140
[] ? hrtimer_interrupt+0xdf/0x220
[] reiserfs_unlink+0x83/0x2e0
[] ? mark_held_locks+0x62/0x80
[] ? trace_hardirqs_on_thunk+0xc/0x10
[] ? restore_all_notrace+0x0/0x18
[] ? xattr_unlink+0x57/0xb0
[] xattr_unlink+0x64/0xb0
[] delete_one_xattr+0x29/0x100
[] reiserfs_for_each_xattr+0x10b/0x290
[] ? delete_one_xattr+0x0/0x100
[] ? mutex_lock_nested+0x299/0x340
[] reiserfs_delete_xattrs+0x1a/0x60
[] ? reiserfs_write_lock_once+0x29/0x50
[] reiserfs_delete_inode+0x9f/0x150
[] ? _atomic_dec_and_lock+0x4f/0x70
[] ? reiserfs_delete_inode+0x0/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] ? mutex_unlock+0x8/0x10
[] ? vfs_readdir+0x7d/0xb0
[] ? filldir64+0x0/0xf0
[] ? sysenter_exit+0xf/0x16
[] ? trace_hardirqs_on_caller+0x124/0x170
[] sys_unlinkat+0x23/0x40
[] sysenter_do_call+0x12/0x32Signed-off-by: Frederic Weisbecker
Tested-by: Christian Kujau
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
reiserfs_unlink() may or may not be called under the reiserfs
lock.
But it also takes the reiserfs lock and can then acquire it
recursively which leads to do_journal_begin_r() that fails to
relax the reiserfs lock before grabbing the journal mutex,
creating an unexpected lock inversion.We need to ensure reiserfs_unlink() won't get the reiserfs lock
recursively using reiserfs_write_lock_once().This fixes the following warning that precedes a lock inversion
report (reiserfs lock journal mutex).------------[ cut here ]------------
WARNING: at fs/reiserfs/lock.c:95 reiserfs_lock_check_recursive+0x3a/0x50()
Hardware name: MS-7418
Unwanted recursive reiserfs lock!
Pid: 3208, comm: dbench Not tainted 2.6.32-atom #177
Call Trace:
[] ? reiserfs_lock_check_recursive+0x3a/0x50
[] ? reiserfs_lock_check_recursive+0x3a/0x50
[] warn_slowpath_common+0x67/0xc0
[] ? reiserfs_lock_check_recursive+0x3a/0x50
[] warn_slowpath_fmt+0x26/0x30
[] reiserfs_lock_check_recursive+0x3a/0x50
[] do_journal_begin_r+0x83/0x360
[] ? __lock_acquire+0x1296/0x19e0
[] ? xattr_unlink+0x57/0xb0
[] journal_begin+0x80/0x130
[] reiserfs_unlink+0x7d/0x2d0
[] ? xattr_unlink+0x57/0xb0
[] ? xattr_unlink+0x57/0xb0
[] ? xattr_unlink+0x57/0xb0
[] xattr_unlink+0x64/0xb0
[] delete_one_xattr+0x29/0x100
[] reiserfs_for_each_xattr+0x10b/0x290
[] ? delete_one_xattr+0x0/0x100
[] ? mutex_lock_nested+0x299/0x340
[] reiserfs_delete_xattrs+0x1a/0x60
[] ? reiserfs_write_lock_once+0x29/0x50
[] reiserfs_delete_inode+0x9f/0x150
[] ? _atomic_dec_and_lock+0x4f/0x70
[] ? reiserfs_delete_inode+0x0/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] ? up_read+0x16/0x30
[] ? do_page_fault+0x187/0x330
[] ? restore_all_notrace+0x0/0x18
[] ? do_page_fault+0x0/0x330
[] ? trace_hardirqs_on_caller+0x124/0x170
[] sys_unlink+0x10/0x20
[] sysenter_do_call+0x12/0x32
---[ end trace 2e35d71a6cc69d0c ]---Signed-off-by: Frederic Weisbecker
Tested-by: Christian Kujau
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
We call xattr_lookup() from reiserfs_xattr_get(). We then hold
the reiserfs lock when we grab the i_mutex. But later, we may
relax the reiserfs lock, creating dependency inversion between
both locks.The lookups and creation jobs ar already protected by the
inode mutex, so we can safely relax the reiserfs lock, dropping
the unwanted reiserfs lock -> i_mutex dependency, as shown
in the following lockdep report:=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #173
-------------------------------------------------------
cp/3204 is trying to acquire lock:
(&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock_once+0x29/0x50but task is already holding lock:
(&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [] open_xa_dir+0xd8/0x1b0which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] open_xa_dir+0x43/0x1b0
[] reiserfs_for_each_xattr+0x62/0x260
[] reiserfs_delete_xattrs+0x1a/0x60
[] reiserfs_delete_inode+0x9f/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] sys_unlink+0x10/0x20
[] sysenter_do_call+0x12/0x32-> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
[] __lock_acquire+0x18f6/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] reiserfs_write_lock_once+0x29/0x50
[] reiserfs_lookup+0x62/0x140
[] __lookup_hash+0xef/0x110
[] lookup_one_len+0x8d/0xc0
[] open_xa_dir+0xea/0x1b0
[] xattr_lookup+0x15/0x160
[] reiserfs_xattr_get+0x56/0x2a0
[] reiserfs_get_acl+0xa2/0x360
[] reiserfs_cache_default_acl+0x3a/0x160
[] reiserfs_mkdir+0x6c/0x2c0
[] vfs_mkdir+0xd6/0x180
[] sys_mkdirat+0xc0/0xd0
[] sys_mkdir+0x20/0x30
[] sysenter_do_call+0x12/0x32other info that might help us debug this:
2 locks held by cp/3204:
#0: (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [] lookup_create+0x26/0xa0
#1: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [] open_xa_dir+0xd8/0x1b0stack backtrace:
Pid: 3204, comm: cp Not tainted 2.6.32-atom #173
Call Trace:
[] ? printk+0x18/0x1a
[] print_circular_bug+0xca/0xd0
[] __lock_acquire+0x18f6/0x19e0
[] ? check_usage+0x6a/0x460
[] lock_acquire+0x68/0x90
[] ? reiserfs_write_lock_once+0x29/0x50
[] ? reiserfs_write_lock_once+0x29/0x50
[] mutex_lock_nested+0x5b/0x340
[] ? reiserfs_write_lock_once+0x29/0x50
[] reiserfs_write_lock_once+0x29/0x50
[] reiserfs_lookup+0x62/0x140
[] ? debug_check_no_locks_freed+0x8a/0x140
[] ? trace_hardirqs_on_caller+0x124/0x170
[] __lookup_hash+0xef/0x110
[] lookup_one_len+0x8d/0xc0
[] open_xa_dir+0xea/0x1b0
[] xattr_lookup+0x15/0x160
[] reiserfs_xattr_get+0x56/0x2a0
[] reiserfs_get_acl+0xa2/0x360
[] ? new_inode+0x27/0xa0
[] reiserfs_cache_default_acl+0x3a/0x160
[] ? _spin_unlock+0x27/0x40
[] reiserfs_mkdir+0x6c/0x2c0
[] ? __d_lookup+0x108/0x190
[] ? mark_held_locks+0x62/0x80
[] ? mutex_lock_nested+0x2bd/0x340
[] ? generic_permission+0x1a/0xa0
[] ? security_inode_permission+0x1e/0x20
[] vfs_mkdir+0xd6/0x180
[] sys_mkdirat+0xc0/0xd0
[] ? up_read+0x16/0x30
[] ? restore_all_notrace+0x0/0x18
[] sys_mkdir+0x20/0x30
[] sysenter_do_call+0x12/0x32Signed-off-by: Frederic Weisbecker
Tested-by: Christian Kujau
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
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: [] __blkdev_put+0x22/0x160but task is already holding lock:
(&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x29/0x40which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&REISERFS_SB(s)->lock){+.+.+.}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] reiserfs_write_lock_once+0x29/0x50
[] reiserfs_get_block+0x85/0x1620
[] do_mpage_readpage+0x1f0/0x6d0
[] mpage_readpages+0xc0/0x100
[] reiserfs_readpages+0x19/0x20
[] __do_page_cache_readahead+0x1bc/0x260
[] ra_submit+0x28/0x40
[] filemap_fault+0x40e/0x420
[] __do_fault+0x3d/0x430
[] handle_mm_fault+0x12e/0x790
[] do_page_fault+0x135/0x330
[] error_code+0x6b/0x70
[] load_elf_binary+0x82a/0x1a10
[] search_binary_handler+0x90/0x1d0
[] do_execve+0x1df/0x250
[] sys_execve+0x46/0x70
[] syscall_call+0x7/0xb-> #2 (&mm->mmap_sem){++++++}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] might_fault+0x8b/0xb0
[] copy_to_user+0x32/0x70
[] filldir64+0xa4/0xf0
[] sysfs_readdir+0x116/0x210
[] vfs_readdir+0x8d/0xb0
[] sys_getdents64+0x69/0xb0
[] sysenter_do_call+0x12/0x32-> #1 (sysfs_mutex){+.+.+.}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] sysfs_addrm_start+0x2c/0xb0
[] create_dir+0x40/0x90
[] sysfs_create_dir+0x2b/0x50
[] kobject_add_internal+0xc2/0x1b0
[] kobject_add_varg+0x31/0x50
[] kobject_add+0x2c/0x60
[] device_add+0x94/0x560
[] add_partition+0x18a/0x2a0
[] rescan_partitions+0x33a/0x450
[] __blkdev_get+0x12f/0x2d0
[] blkdev_get+0xa/0x10
[] register_disk+0x108/0x130
[] add_disk+0xd9/0x130
[] sd_probe_async+0x105/0x1d0
[] async_thread+0xcf/0x230
[] kthread+0x74/0x80
[] kernel_thread_helper+0x7/0x3c-> #0 (&bdev->bd_mutex){+.+.+.}:
[] __lock_acquire+0x18f6/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] __blkdev_put+0x22/0x160
[] blkdev_put+0xa/0x10
[] free_journal_ram+0xd2/0x130
[] do_journal_release+0x98/0x190
[] journal_release+0xa/0x10
[] reiserfs_put_super+0x36/0x130
[] generic_shutdown_super+0x4f/0xe0
[] kill_block_super+0x25/0x40
[] reiserfs_kill_sb+0x7f/0x90
[] deactivate_super+0x7a/0x90
[] mntput_no_expire+0x98/0xd0
[] sys_umount+0x4c/0x310
[] sys_oldumount+0x19/0x20
[] sysenter_do_call+0x12/0x32other info that might help us debug this:
2 locks held by umount/3904:
#0: (&type->s_umount_key#30){+++++.}, at: [] deactivate_super+0x75/0x90
#1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x29/0x40stack backtrace:
Pid: 3904, comm: umount Not tainted 2.6.32-atom #172
Call Trace:
[] ? printk+0x18/0x1a
[] print_circular_bug+0xca/0xd0
[] __lock_acquire+0x18f6/0x19e0
[] ? free_pcppages_bulk+0x1f/0x250
[] lock_acquire+0x68/0x90
[] ? __blkdev_put+0x22/0x160
[] ? __blkdev_put+0x22/0x160
[] mutex_lock_nested+0x5b/0x340
[] ? __blkdev_put+0x22/0x160
[] ? mark_held_locks+0x62/0x80
[] ? kfree+0x92/0xd0
[] __blkdev_put+0x22/0x160
[] ? trace_hardirqs_on+0xb/0x10
[] blkdev_put+0xa/0x10
[] free_journal_ram+0xd2/0x130
[] do_journal_release+0x98/0x190
[] journal_release+0xa/0x10
[] reiserfs_put_super+0x36/0x130
[] ? up_write+0x16/0x30
[] generic_shutdown_super+0x4f/0xe0
[] kill_block_super+0x25/0x40
[] ? vfs_quota_off+0x0/0x20
[] reiserfs_kill_sb+0x7f/0x90
[] deactivate_super+0x7a/0x90
[] mntput_no_expire+0x98/0xd0
[] sys_umount+0x4c/0x310
[] sys_oldumount+0x19/0x20
[] sysenter_do_call+0x12/0x32Signed-off-by: Frederic Weisbecker
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
While deleting the xattrs of an inode, we hold the reiserfs lock
and grab the inode->i_mutex of the targeted inode and the root
private xattr directory.Later on, we may relax the reiserfs lock for various reasons, this
creates inverted dependencies.We can remove the reiserfs lock -> i_mutex dependency by relaxing
the former before calling open_xa_dir(). This is fine because the
lookup and creation of xattr private directories done in
open_xa_dir() are covered by the targeted inode mutexes. And deeper
operations in the tree are still done under the write lock.This fixes the following lockdep report:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #173
-------------------------------------------------------
cp/3204 is trying to acquire lock:
(&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock_once+0x29/0x50but task is already holding lock:
(&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [] open_xa_dir+0xd8/0x1b0which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
[] __lock_acquire+0x11ff/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] open_xa_dir+0x43/0x1b0
[] reiserfs_for_each_xattr+0x62/0x260
[] reiserfs_delete_xattrs+0x1a/0x60
[] reiserfs_delete_inode+0x9f/0x150
[] generic_delete_inode+0xa2/0x170
[] generic_drop_inode+0x4f/0x70
[] iput+0x47/0x50
[] do_unlinkat+0xd5/0x160
[] sys_unlink+0x10/0x20
[] sysenter_do_call+0x12/0x32-> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
[] __lock_acquire+0x18f6/0x19e0
[] lock_acquire+0x68/0x90
[] mutex_lock_nested+0x5b/0x340
[] reiserfs_write_lock_once+0x29/0x50
[] reiserfs_lookup+0x62/0x140
[] __lookup_hash+0xef/0x110
[] lookup_one_len+0x8d/0xc0
[] open_xa_dir+0xea/0x1b0
[] xattr_lookup+0x15/0x160
[] reiserfs_xattr_get+0x56/0x2a0
[] reiserfs_get_acl+0xa2/0x360
[] reiserfs_cache_default_acl+0x3a/0x160
[] reiserfs_mkdir+0x6c/0x2c0
[] vfs_mkdir+0xd6/0x180
[] sys_mkdirat+0xc0/0xd0
[] sys_mkdir+0x20/0x30
[] sysenter_do_call+0x12/0x32other info that might help us debug this:
2 locks held by cp/3204:
#0: (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [] lookup_create+0x26/0xa0
#1: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [] open_xa_dir+0xd8/0x1b0stack backtrace:
Pid: 3204, comm: cp Not tainted 2.6.32-atom #173
Call Trace:
[] ? printk+0x18/0x1a
[] print_circular_bug+0xca/0xd0
[] __lock_acquire+0x18f6/0x19e0
[] ? check_usage+0x6a/0x460
[] lock_acquire+0x68/0x90
[] ? reiserfs_write_lock_once+0x29/0x50
[] ? reiserfs_write_lock_once+0x29/0x50
[] mutex_lock_nested+0x5b/0x340
[] ? reiserfs_write_lock_once+0x29/0x50
[] reiserfs_write_lock_once+0x29/0x50
[] reiserfs_lookup+0x62/0x140
[] ? debug_check_no_locks_freed+0x8a/0x140
[] ? trace_hardirqs_on_caller+0x124/0x170
[] __lookup_hash+0xef/0x110
[] lookup_one_len+0x8d/0xc0
[] open_xa_dir+0xea/0x1b0
[] xattr_lookup+0x15/0x160
[] reiserfs_xattr_get+0x56/0x2a0
[] reiserfs_get_acl+0xa2/0x360
[] ? new_inode+0x27/0xa0
[] reiserfs_cache_default_acl+0x3a/0x160
[] ? _spin_unlock+0x27/0x40
[] reiserfs_mkdir+0x6c/0x2c0
[] ? __d_lookup+0x108/0x190
[] ? mark_held_locks+0x62/0x80
[] ? mutex_lock_nested+0x2bd/0x340
[] ? generic_permission+0x1a/0xa0
[] ? security_inode_permission+0x1e/0x20
[] vfs_mkdir+0xd6/0x180
[] sys_mkdirat+0xc0/0xd0
[] ? up_read+0x16/0x30
[] ? restore_all_notrace+0x0/0x18
[] sys_mkdir+0x20/0x30
[] sysenter_do_call+0x12/0x32v2: Don't drop reiserfs_mutex_lock_nested_safe() as we'll still
need it laterSigned-off-by: Frederic Weisbecker
Tested-by: Christian Kujau
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
When we relax the reiserfs lock to avoid creating unwanted
dependencies against others locks while grabbing these,
we want to ensure it has not been taken recursively, otherwise
the lock won't be really relaxed. Only its depth will be decreased.
The unwanted dependency would then actually happen.To prevent from that, add a reiserfs_lock_check_recursive() call
in the places that need it.Signed-off-by: Frederic Weisbecker
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar -
i_xattr_sem depends on the reiserfs lock. But after we grab
i_xattr_sem, we may relax/relock the reiserfs lock while waiting
on a freezed filesystem, creating a dependency inversion between
the two locks.In order to avoid the i_xattr_sem -> reiserfs lock dependency, let's
create a reiserfs_down_read_safe() that acts like
reiserfs_mutex_lock_safe(): relax the reiserfs lock while grabbing
another lock to avoid undesired dependencies induced by the
heivyweight reiserfs lock.This fixes the following warning:
[ 990.005931] =======================================================
[ 990.012373] [ INFO: possible circular locking dependency detected ]
[ 990.013233] 2.6.33-rc1 #1
[ 990.013233] -------------------------------------------------------
[ 990.013233] dbench/1891 is trying to acquire lock:
[ 990.013233] (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x35/0x50
[ 990.013233]
[ 990.013233] but task is already holding lock:
[ 990.013233] (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}, at: [] reiserfs_xattr_set_handle+0x8a/0x470
[ 990.013233]
[ 990.013233] which lock already depends on the new lock.
[ 990.013233]
[ 990.013233]
[ 990.013233] the existing dependency chain (in reverse order) is:
[ 990.013233]
[ 990.013233] -> #1 (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}:
[ 990.013233] [] __lock_acquire+0xf9c/0x1560
[ 990.013233] [] lock_acquire+0x8f/0xb0
[ 990.013233] [] down_write+0x44/0x80
[ 990.013233] [] reiserfs_xattr_set_handle+0x8a/0x470
[ 990.013233] [] reiserfs_xattr_set+0xb0/0x150
[ 990.013233] [] user_set+0x8a/0x90
[ 990.013233] [] reiserfs_setxattr+0xaa/0xb0
[ 990.013233] [] __vfs_setxattr_noperm+0x36/0xa0
[ 990.013233] [] vfs_setxattr+0xbc/0xc0
[ 990.013233] [] setxattr+0xc0/0x150
[ 990.013233] [] sys_fsetxattr+0x8d/0xa0
[ 990.013233] [] system_call_fastpath+0x16/0x1b
[ 990.013233]
[ 990.013233] -> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
[ 990.013233] [] __lock_acquire+0x12d0/0x1560
[ 990.013233] [] lock_acquire+0x8f/0xb0
[ 990.013233] [] __mutex_lock_common+0x47/0x3b0
[ 990.013233] [] mutex_lock_nested+0x3e/0x50
[ 990.013233] [] reiserfs_write_lock+0x35/0x50
[ 990.013233] [] reiserfs_prepare_write+0x45/0x180
[ 990.013233] [] reiserfs_xattr_set_handle+0x2a6/0x470
[ 990.013233] [] reiserfs_xattr_set+0xb0/0x150
[ 990.013233] [] user_set+0x8a/0x90
[ 990.013233] [] reiserfs_setxattr+0xaa/0xb0
[ 990.013233] [] __vfs_setxattr_noperm+0x36/0xa0
[ 990.013233] [] vfs_setxattr+0xbc/0xc0
[ 990.013233] [] setxattr+0xc0/0x150
[ 990.013233] [] sys_fsetxattr+0x8d/0xa0
[ 990.013233] [] system_call_fastpath+0x16/0x1b
[ 990.013233]
[ 990.013233] other info that might help us debug this:
[ 990.013233]
[ 990.013233] 2 locks held by dbench/1891:
[ 990.013233] #0: (&sb->s_type->i_mutex_key#12){+.+.+.}, at: [] vfs_setxattr+0x78/0xc0
[ 990.013233] #1: (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}, at: [] reiserfs_xattr_set_handle+0x8a/0x470
[ 990.013233]
[ 990.013233] stack backtrace:
[ 990.013233] Pid: 1891, comm: dbench Not tainted 2.6.33-rc1 #1
[ 990.013233] Call Trace:
[ 990.013233] [] print_circular_bug+0xe9/0xf0
[ 990.013233] [] __lock_acquire+0x12d0/0x1560
[ 990.013233] [] ? reiserfs_xattr_set_handle+0x8a/0x470
[ 990.013233] [] lock_acquire+0x8f/0xb0
[ 990.013233] [] ? reiserfs_write_lock+0x35/0x50
[ 990.013233] [] ? reiserfs_xattr_set_handle+0x8a/0x470
[ 990.013233] [] __mutex_lock_common+0x47/0x3b0
[ 990.013233] [] ? reiserfs_write_lock+0x35/0x50
[ 990.013233] [] ? reiserfs_write_lock+0x35/0x50
[ 990.013233] [] ? mark_held_locks+0x72/0xa0
[ 990.013233] [] ? __mutex_unlock_slowpath+0xbd/0x140
[ 990.013233] [] ? trace_hardirqs_on_caller+0x14d/0x1a0
[ 990.013233] [] mutex_lock_nested+0x3e/0x50
[ 990.013233] [] reiserfs_write_lock+0x35/0x50
[ 990.013233] [] reiserfs_prepare_write+0x45/0x180
[ 990.013233] [] reiserfs_xattr_set_handle+0x2a6/0x470
[ 990.013233] [] reiserfs_xattr_set+0xb0/0x150
[ 990.013233] [] ? __mutex_lock_common+0x284/0x3b0
[ 990.013233] [] user_set+0x8a/0x90
[ 990.013233] [] reiserfs_setxattr+0xaa/0xb0
[ 990.013233] [] __vfs_setxattr_noperm+0x36/0xa0
[ 990.013233] [] vfs_setxattr+0xbc/0xc0
[ 990.013233] [] setxattr+0xc0/0x150
[ 990.013233] [] ? sched_clock_cpu+0xb8/0x100
[ 990.013233] [] ? trace_hardirqs_off+0xd/0x10
[ 990.013233] [] ? cpu_clock+0x43/0x50
[ 990.013233] [] ? fget+0xb0/0x110
[ 990.013233] [] ? fget+0x0/0x110
[ 990.013233] [] ? sysret_check+0x27/0x62
[ 990.013233] [] sys_fsetxattr+0x8d/0xa0
[ 990.013233] [] system_call_fastpath+0x16/0x1bReported-and-tested-by: Christian Kujau
Signed-off-by: Frederic Weisbecker
Cc: Alexander Beregalov
Cc: Chris Mason
Cc: Ingo Molnar
01 Jan, 2010
3 commits
-
In the past, ext4_calc_metadata_amount(), and its sub-functions
ext4_ext_calc_metadata_amount() and ext4_indirect_calc_metadata_amount()
badly over-estimated the number of metadata blocks that might be
required for delayed allocation blocks. This didn't matter as much
when functions which managed the reserved metadata blocks were more
aggressive about dropping reserved metadata blocks as delayed
allocation blocks were written, but unfortunately they were too
aggressive. This was fixed in commit 0637c6f, but as a result the
over-estimation by ext4_calc_metadata_amount() would lead to reserving
2-3 times the number of pending delayed allocation blocks as
potentially required metadata blocks. So if there are 1 megabytes of
blocks which have been not yet been allocation, up to 3 megabytes of
space would get reserved out of the user's quota and from the file
system free space pool until all of the inode's data blocks have been
allocated.This commit addresses this problem by much more accurately estimating
the number of metadata blocks that will be required. It will still
somewhat over-estimate the number of blocks needed, since it must make
a worst case estimate not knowing which physical blocks will be
needed, but it is much more accurate than before.Signed-off-by: "Theodore Ts'o"
-
Commit 0637c6f had a typo which caused the reserved metadata blocks to
not be released correctly. Fix this.Signed-off-by: "Theodore Ts'o"
-
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] Enable mmap on forcedirectio mounts
cifs: NULL out tcon, pSesInfo, and srvTcp pointers when chasing DFS referrals
31 Dec, 2009
3 commits
-
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Patch up how we claim metadata blocks for quota purposes
ext4: Ensure zeroout blocks have no dirty metadata
ext4: return correct wbc.nr_to_write in ext4_da_writepages
ext4: Update documentation to correct the inode_readahead_blks option name
jbd2: don't use __GFP_NOFAIL in journal_init_common()
ext4: flush delalloc blocks when space is low
fs-writeback: Add helper function to start writeback if idle
ext4: Eliminate potential double free on error path
ext4: fix unsigned long long printk warning in super.c
ext4, jbd2: Add barriers for file systems with exernal journals
ext4: replace BUG() with return -EIO in ext4_ext_get_blocks
ext4: add module aliases for ext2 and ext3
ext4: Don't ask about supporting ext2/3 in ext4 if ext4 is not configured
ext4: remove unused #include -
generic_permission was refusing CAP_DAC_READ_SEARCH-enabled
processes from opening DAC-protected files read-only, because
do_filp_open adds MAY_OPEN to the open mask.Ignore MAY_OPEN. After this patch, CAP_DAC_READ_SEARCH is
again sufficient to open(fname, O_RDONLY) on a file to which
DAC otherwise refuses us read permission.Reported-by: Mike Kazantsev
Signed-off-by: Serge E. Hallyn
Tested-by: Mike Kazantsev
Signed-off-by: Linus Torvalds -
As reported in Kernel Bugzilla #14936, commit d21cd8f triggered a BUG
in the function ext4_da_update_reserve_space() found in
fs/ext4/inode.c. The root cause of this BUG() was caused by the fact
that ext4_calc_metadata_amount() can severely over-estimate how many
metadata blocks will be needed, especially when using direct
block-mapped files.In addition, it can also badly *under* estimate how much space is
needed, since ext4_calc_metadata_amount() assumes that the blocks are
contiguous, and this is not always true. If the application is
writing blocks to a sparse file, the number of metadata blocks
necessary can be severly underestimated by the functions
ext4_da_reserve_space(), ext4_da_update_reserve_space() and
ext4_da_release_space(). This was the cause of the dq_claim_space
reports found on kerneloops.org.Unfortunately, doing this right means that we need to massively
over-estimate the amount of free space needed. So in some cases we
may need to force the inode to be written to disk asynchronously in
to avoid spurious quota failures.http://bugzilla.kernel.org/show_bug.cgi?id=14936
Signed-off-by: "Theodore Ts'o"
30 Dec, 2009
2 commits
-
This fixes a bug (found by Curt Wohlgemuth) in which new blocks
returned from an extent created with ext4_ext_zeroout() can have dirty
metadata still associated with them.Signed-off-by: Aneesh Kumar K.V
Signed-off-by: Curt Wohlgemuth
Signed-off-by: "Theodore Ts'o" -
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
Signed-off-by: Frederic Weisbecker
Cc: Chris Mason
Cc: Ingo Molnar
26 Dec, 2009
1 commit
-
When ext4_da_writepages increases the nr_to_write in writeback_control
then it must always re-base the return value. Originally there was a
(misguided) attempt prevent wbc.nr_to_write from going negative. In
fact, it's necessary to allow nr_to_write to be negative so that
wb_writeback() can correctly calculate how many pages were actually
written.Signed-off-by: Richard Kennedy
Signed-off-by: "Theodore Ts'o"
25 Dec, 2009
3 commits
-
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.Signed-off-by: Tobias Klauser
Signed-off-by: Ryusuke Konishi -
This is a trivial style fix patch to mend errors/warnings
reported by "checkpatch.pl --file".Signed-off-by: Jiro SEKIBA
Signed-off-by: Ryusuke Konishi -
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
ocfs2/trivial: Use le16_to_cpu for a disk value in xattr.c
ocfs2/trivial: Use proper mask for 2 places in hearbeat.c
Ocfs2: Let ocfs2 support fiemap for symlink and fast symlink.
Ocfs2: Should ocfs2 support fiemap for S_IFDIR inode?
ocfs2: Use FIEMAP_EXTENT_SHARED
fiemap: Add new extent flag FIEMAP_EXTENT_SHARED
ocfs2: replace u8 by __u8 in ocfs2_fs.h
ocfs2: explicit declare uninitialized var in user_cluster_connect()
ocfs2-devel: remove redundant OCFS2_MOUNT_POSIX_ACL check in ocfs2_get_acl_nolock()
ocfs2: return -EAGAIN instead of EAGAIN in dlm
ocfs2/cluster: Make fence method configurable - v2
ocfs2: Set MS_POSIXACL on remount
ocfs2: Make acl use the default
ocfs2: Always include ACL support
24 Dec, 2009
7 commits
-
In ocfs2_value_metas_in_xattr_header, we should Use
le16_to_cpu for ocfs2_extent_list.l_next_free_rec.Signed-off-by: Tao Ma
Signed-off-by: Joel Becker -
I just noticed today that there are 2 places of "mlog(0,...)"
in fs/ocfs2/cluster/heartbeat.c, but actually have no default
mask prefix in that file.
So change them to mlog(ML_HEARTBEAT,...).Signed-off-by: Tao Ma
Signed-off-by: Joel Becker -
For fast symlink, it can be treated the same as inlined files since
the data extent we want to return of both case all were stored in
metadata block. For symlink, it can be simply treated the same as we
did for regular files.Signed-off-by: Tristan Ye
Acked-by: Sunil Mushran
Signed-off-by: Joel Becker -
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
devtmpfs: unlock mutex in case of string allocation error
Driver core: export platform_device_register_data as a GPL symbol
driver core: Prevent reference to freed memory on error path
Driver-core: Fix bogus 0 error return in device_add()
Driver core: driver_attribute parameters can often be const*
Driver core: bin_attribute parameters can often be const*
Driver core: device_attribute parameters can often be const*
Doc/stable rules: add new cherry-pick logic
vfs: get_sb_single() - do not pass options twice
devtmpfs: Convert dirlock to a mutex -
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
ocfs2: Set i_nlink properly during reflink.
ocfs2: Add reflinked file's inode to inode hash eariler.
ocfs2: refcounttree.c cleanup.
ocfs2: Find proper end cpos for a leaf refcount block. -
Many struct bin_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore
make the promise not to, which will let those descriptors
be put in a ro section.Signed-off-by: Phil Carmody
Signed-off-by: Greg Kroah-Hartman -
Filesystem code usually destroys the option buffer while
parsing it. This leads to errors when the same buffer is
passed twice. In case we fill a new superblock do not call
remount.This is needed to quite a warning that the debugfs code
causes every boot.Cc: Miklos Szeredi
Signed-off-by: Kay Sievers
Signed-off-by: Greg Kroah-Hartman
23 Dec, 2009
5 commits
-
It triggers the warning in get_page_from_freelist(), and it isn't
appropriate to use __GFP_NOFAIL here anyway.Addresses http://bugzilla.kernel.org/show_bug.cgi?id=14843
Reported-by: Christian Casteyde
Signed-off-by: Andrew Morton
Signed-off-by: "Theodore Ts'o" -
Creating many small files in rapid succession on a small
filesystem can lead to spurious ENOSPC; on a 104MB filesystem:for i in `seq 1 22500`; do
echo -n > $SCRATCH_MNT/$i
echo XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX > $SCRATCH_MNT/$i
doneleads to ENOSPC even though after a sync, 40% of the fs is free
again.This is because we reserve worst-case metadata for delalloc writes,
and when data is allocated that worst-case reservation is not
usually needed.When freespace is low, kicking off an async writeback will start
converting that worst-case space usage into something more realistic,
almost always freeing up space to continue.This resolves the testcase for me, and survives all 4 generic
ENOSPC tests in xfstests.We'll still need a hard synchronous sync to squeeze out the last bit,
but this fixes things up to a large degree.Signed-off-by: Eric Sandeen
Signed-off-by: "Theodore Ts'o" -
ext4, at least, would like to start pushing on writeback if it starts
to get close to ENOSPC when reserving worst-case blocks for delalloc
writes. Writing out delalloc data will convert those worst-case
predictions into usually smaller actual usage, freeing up space
before we hit ENOSPC based on this speculation.Thanks to Jens for the suggestion for the helper function,
& the naming help.I've made the helper return status on whether writeback was
started even though I don't plan to use it in the ext4 patch;
it seems like it would be potentially useful to test this
in some cases.Signed-off-by: Eric Sandeen
Acked-by: Jan Kara -
b_entry_name and buffer are initially NULL, are initialized within a loop
to the result of calling kmalloc, and are freed at the bottom of this loop.
The loop contains gotos to cleanup, which also frees b_entry_name and
buffer. Some of these gotos are before the reinitializations of
b_entry_name and buffer. To maintain the invariant that b_entry_name and
buffer are NULL at the top of the loop, and thus acceptable arguments to
kfree, these variables are now set to NULL after the kfrees.This seems to be the simplest solution. A more complicated solution
would be to introduce more labels in the error handling code at the end of
the function.A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)//
@r@
identifier E;
expression E1;
iterator I;
statement S;
@@*kfree(E);
... when != E = E1
when != I(E,...) S
when != &E
*kfree(E);
//Signed-off-by: Julia Lawall
Signed-off-by: "Theodore Ts'o" -
sparc64 allmodconfig:
fs/ext4/super.c: In function `lifetime_write_kbytes_show':
fs/ext4/super.c:2174: warning: long long unsigned int format, long unsigned int arg (arg 4)
fs/ext4/super.c:2174: warning: long long unsigned int format, long unsigned int arg (arg 4)Signed-off-by: Andrew Morton
Signed-off-by: "Theodore Ts'o"
