linux-toradex.git/fs/logfs, branch v3.3.5 Linux kernel for Apalis and Colibri modules mtd: fix merge conflict resolution breakage 2012-02-01T19:10:24+00:00 Artem Bityutskiy artem.bityutskiy@linux.intel.com 2012-02-01T19:10:24+00:00 7d731019218e49a9811f6d0adec4b1cfcb752bed This patch fixes merge conflict resolution breakage introduced by merge d3712b9dfcf4 ("Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream"). The commit changed 'mtd_can_have_bb()' function and made it always return zero, which is incorrect. Instead, we need it to return whether the underlying flash device can have bad eraseblocks or not. UBI needs this information because it affects how it handles the underlying flash. E.g., if the underlying flash is NOR, it cannot have bad blocks and any write or erase error is fatal, and all we can do is to switch to R/O mode. We do not need to reserve a pool of good eraseblocks for bad eraseblocks handling, and so on. This patch also removes 'mtd_can_have_bb()' invocations from Logfs to ensure correct Logfs behavior. I've tested that with this patch UBI works on top of NOR and NAND flashes emulated by mtdram and nandsim correspondingly. This patch is based on patch from Linus Torvalds. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Acked-by: Jörn Engel <joern@logfs.org> Acked-by: Prasad Joshi <prasadjoshi.linux@gmail.com> Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This patch fixes merge conflict resolution breakage introduced by merge
d3712b9dfcf4 ("Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream").

The commit changed 'mtd_can_have_bb()' function and made it always
return zero, which is incorrect.  Instead, we need it to return whether
the underlying flash device can have bad eraseblocks or not.  UBI needs
this information because it affects how it handles the underlying flash.
E.g., if the underlying flash is NOR, it cannot have bad blocks and any
write or erase error is fatal, and all we can do is to switch to R/O
mode.  We do not need to reserve a pool of good eraseblocks for bad
eraseblocks handling, and so on.

This patch also removes 'mtd_can_have_bb()' invocations from Logfs to
ensure correct Logfs behavior.

I've tested that with this patch UBI works on top of NOR and NAND
flashes emulated by mtdram and nandsim correspondingly.

This patch is based on patch from Linus Torvalds.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Jörn Engel <joern@logfs.org>
Acked-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream 2012-01-31T17:23:59+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-31T17:23:59+00:00 d3712b9dfcf44ca145cf87e7f4096fa2d923471a There are few important bug fixes for LogFS * tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream: Logfs: Allow NULL block_isbad() methods logfs: Grow inode in delete path logfs: Free areas before calling generic_shutdown_super() logfs: remove useless BUG_ON MAINTAINERS: Add Prasad Joshi in LogFS maintiners logfs: Propagate page parameter to __logfs_write_inode logfs: set superblock shutdown flag after generic sb shutdown logfs: take write mutex lock during fsync and sync logfs: Prevent memory corruption logfs: update page reference count for pined pages Fix up conflict in fs/logfs/dev_mtd.c due to semantic change in what "mtd->block_isbad" means in commit f2933e86ad93: "Logfs: Allow NULL block_isbad() methods" clashing with the abstraction changes in the commits 7086c19d0742: "mtd: introduce mtd_block_isbad interface" and d58b27ed58a3: "logfs: do not use 'mtd->block_isbad' directly". This resolution takes the semantics from commit f2933e86ad93, and just makes mtd_block_isbad() return zero (false) if the 'block_isbad' function is NULL. But that also means that now "mtd_can_have_bb()" always returns 0. Now, "mtd_block_markbad()" will obviously return an error if the low-level driver doesn't support bad blocks, so this is somewhat non-symmetric, but it actually makes sense if a NULL "block_isbad" function is considered to mean "I assume that all my blocks are always good". 
There are few important bug fixes for LogFS

* tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream:
  Logfs: Allow NULL block_isbad() methods
  logfs: Grow inode in delete path
  logfs: Free areas before calling generic_shutdown_super()
  logfs: remove useless BUG_ON
  MAINTAINERS: Add Prasad Joshi in LogFS maintiners
  logfs: Propagate page parameter to __logfs_write_inode
  logfs: set superblock shutdown flag after generic sb shutdown
  logfs: take write mutex lock during fsync and sync
  logfs: Prevent memory corruption
  logfs: update page reference count for pined pages

Fix up conflict in fs/logfs/dev_mtd.c due to semantic change in what
"mtd->block_isbad" means in commit f2933e86ad93: "Logfs: Allow NULL
block_isbad() methods" clashing with the abstraction changes in the
commits 7086c19d0742: "mtd: introduce mtd_block_isbad interface" and
d58b27ed58a3: "logfs: do not use 'mtd->block_isbad' directly".

This resolution takes the semantics from commit f2933e86ad93, and just
makes mtd_block_isbad() return zero (false) if the 'block_isbad'
function is NULL.  But that also means that now "mtd_can_have_bb()"
always returns 0.

Now, "mtd_block_markbad()" will obviously return an error if the
low-level driver doesn't support bad blocks, so this is somewhat
non-symmetric, but it actually makes sense if a NULL "block_isbad"
function is considered to mean "I assume that all my blocks are always
good".
Logfs: Allow NULL block_isbad() methods 2012-01-28T06:13:40+00:00 Joern Engel joern@logfs.org 2011-08-05T09:09:55+00:00 f2933e86ad93a8d1287079d59e67afd6f4166a9d Not all mtd drivers define block_isbad(). Let's assume no bad blocks instead of refusing to mount. Signed-off-by: Joern Engel <joern@logfs.org> 
Not all mtd drivers define block_isbad().  Let's assume no bad blocks
instead of refusing to mount.

Signed-off-by: Joern Engel <joern@logfs.org>
logfs: Grow inode in delete path 2012-01-28T06:13:07+00:00 Joern Engel joern@logfs.org 2011-08-05T09:13:30+00:00 bbe01387129f76fa4bec17904eb14c4bdc3c179f Can be necessary if an inode gets deleted (through -ENOSPC) before being written. Might be better to move this into logfs_write_rec(), but for now go with the stupid&safe patch. Signed-off-by: Joern Engel <joern@logfs.org> 
Can be necessary if an inode gets deleted (through -ENOSPC) before being
written.  Might be better to move this into logfs_write_rec(), but for
now go with the stupid&safe patch.

Signed-off-by: Joern Engel <joern@logfs.org>
logfs: Free areas before calling generic_shutdown_super() 2012-01-28T06:12:39+00:00 Joern Engel joern@logfs.org 2011-08-05T09:18:19+00:00 1bcceaff8cbe5e5698ccf1015c9a938aa72718c4 Or hit an assertion in map_invalidatepage() instead. Signed-off-by: Joern Engel <joern@logfs.org> 
Or hit an assertion in map_invalidatepage() instead.

Signed-off-by: Joern Engel <joern@logfs.org>
logfs: remove useless BUG_ON 2012-01-28T06:11:56+00:00 Joern Engel joern@logfs.org 2011-09-12T15:39:16+00:00 6c69494f6b442834f26377e02d43fc8e1272221d It prevents write sizes >4k. Signed-off-by: Joern Engel <joern@logfs.org> 
It prevents write sizes >4k.

Signed-off-by: Joern Engel <joern@logfs.org>
logfs: Propagate page parameter to __logfs_write_inode 2012-01-28T06:08:25+00:00 Prasad Joshi prasadjoshi.linux@gmail.com 2011-10-02T18:16:51+00:00 0bd90387ed5a8abbcf43391b480efdc211721cfe During GC LogFS has to rewrite each valid block to a separate segment. Rewrite operation reads data from an old segment and writes it to a newly allocated segment. Since every write operation changes data block pointers maintained in inode, inode should also be rewritten. In GC path to avoid AB-BA deadlock LogFS marks a page with PG_pre_locked in addition to locking the page (PG_locked). The page lock is ignored iff the page is pre-locked. LogFS uses a special file called segment file. The segment file maintains an 8 bytes entry for every segment. It keeps track of erase count, level etc. for every segment. Bad things happen with a segment belonging to the segment file is GCed ------------[ cut here ]------------ kernel BUG at /home/prasad/logfs/readwrite.c:297! invalid opcode: 0000 [#1] SMP Modules linked in: logfs joydev usbhid hid psmouse e1000 i2c_piix4 serio_raw [last unloaded: logfs] Pid: 20161, comm: mount Not tainted 3.1.0-rc3+ #3 innotek GmbH VirtualBox EIP: 0060:[<f809132a>] EFLAGS: 00010292 CPU: 0 EIP is at logfs_lock_write_page+0x6a/0x70 [logfs] EAX: 00000027 EBX: f73f5b20 ECX: c16007c8 EDX: 00000094 ESI: 00000000 EDI: e59be6e4 EBP: c7337b28 ESP: c7337b18 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process mount (pid: 20161, ti=c7336000 task=eb323f70 task.ti=c7336000) Stack: f8099a3d c7337b24 f73f5b20 00001002 c7337b50 f8091f6d f8099a4d f80994e4 00000003 00000000 c7337b68 00000000 c67e4400 00001000 c7337b80 f80935e5 00000000 00000000 00000000 00000000 e1fcf000 0000000f e59be618 c70bf900 Call Trace: [<f8091f6d>] logfs_get_write_page.clone.16+0xdd/0x100 [logfs] [<f80935e5>] logfs_mod_segment_entry+0x55/0x110 [logfs] [<f809460d>] logfs_get_segment_entry+0x1d/0x20 [logfs] [<f8091060>] ? logfs_cleanup_journal+0x50/0x50 [logfs] [<f809521b>] ostore_get_erase_count+0x1b/0x40 [logfs] [<f80965b8>] logfs_open_area+0xc8/0x150 [logfs] [<c141a7ec>] ? kmemleak_alloc+0x2c/0x60 [<f809668e>] __logfs_segment_write.clone.16+0x4e/0x1b0 [logfs] [<c10dd563>] ? mempool_kmalloc+0x13/0x20 [<c10dd563>] ? mempool_kmalloc+0x13/0x20 [<f809696f>] logfs_segment_write+0x17f/0x1d0 [logfs] [<f8092e8c>] logfs_write_i0+0x11c/0x180 [logfs] [<f8092f35>] logfs_write_direct+0x45/0x90 [logfs] [<f80934cd>] __logfs_write_buf+0xbd/0xf0 [logfs] [<c102900e>] ? kmap_atomic_prot+0x4e/0xe0 [<f809424b>] logfs_write_buf+0x3b/0x60 [logfs] [<f80947a9>] __logfs_write_inode+0xa9/0x110 [logfs] [<f8094cb0>] logfs_rewrite_block+0xc0/0x110 [logfs] [<f8095300>] ? get_mapping_page+0x10/0x60 [logfs] [<f8095aa0>] ? logfs_load_object_aliases+0x2e0/0x2f0 [logfs] [<f808e57d>] logfs_gc_segment+0x2ad/0x310 [logfs] [<f808e62a>] __logfs_gc_once+0x4a/0x80 [logfs] [<f808ed43>] logfs_gc_pass+0x683/0x6a0 [logfs] [<f8097a89>] logfs_mount+0x5a9/0x680 [logfs] [<c1126b21>] mount_fs+0x21/0xd0 [<c10f6f6f>] ? __alloc_percpu+0xf/0x20 [<c113da41>] ? alloc_vfsmnt+0xb1/0x130 [<c113db4b>] vfs_kern_mount+0x4b/0xa0 [<c113e06e>] do_kern_mount+0x3e/0xe0 [<c113f60d>] do_mount+0x34d/0x670 [<c10f2749>] ? strndup_user+0x49/0x70 [<c113fcab>] sys_mount+0x6b/0xa0 [<c142d87c>] syscall_call+0x7/0xb Code: f8 e8 8b 93 39 c9 8b 45 f8 3e 0f ba 28 00 19 d2 85 d2 74 ca eb d0 0f 0b 8d 45 fc 89 44 24 04 c7 04 24 3d 9a 09 f8 e8 09 92 39 c9 <0f> 0b 8d 74 26 00 55 89 e5 3e 8d 74 26 00 8b 10 80 e6 01 74 09 EIP: [<f809132a>] logfs_lock_write_page+0x6a/0x70 [logfs] SS:ESP 0068:c7337b18 ---[ end trace 96e67d5b3aa3d6ca ]--- The patch passes locked page to __logfs_write_inode. It calls function logfs_get_wblocks() to pre-lock the page. This ensures any further attempts to lock the page are ignored (esp from get_erase_count). Acked-by: Joern Engel <joern@logfs.org> Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com> 
During GC LogFS has to rewrite each valid block to a separate segment.
Rewrite operation reads data from an old segment and writes it to a
newly allocated segment. Since every write operation changes data
block pointers maintained in inode, inode should also be rewritten.

In GC path to avoid AB-BA deadlock LogFS marks a page with
PG_pre_locked in addition to locking the page (PG_locked). The page
lock is ignored iff the page is pre-locked.

LogFS uses a special file called segment file. The segment file
maintains an 8 bytes entry for every segment. It keeps track of erase
count, level etc. for every segment.

Bad things happen with a segment belonging to the segment file is GCed

 ------------[ cut here ]------------
kernel BUG at /home/prasad/logfs/readwrite.c:297!
invalid opcode: 0000 [#1] SMP
Modules linked in: logfs joydev usbhid hid psmouse e1000 i2c_piix4
		serio_raw [last unloaded: logfs]
Pid: 20161, comm: mount Not tainted 3.1.0-rc3+ #3 innotek GmbH
		VirtualBox
EIP: 0060:[<f809132a>] EFLAGS: 00010292 CPU: 0
EIP is at logfs_lock_write_page+0x6a/0x70 [logfs]
EAX: 00000027 EBX: f73f5b20 ECX: c16007c8 EDX: 00000094
ESI: 00000000 EDI: e59be6e4 EBP: c7337b28 ESP: c7337b18
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process mount (pid: 20161, ti=c7336000 task=eb323f70 task.ti=c7336000)
Stack:
f8099a3d c7337b24 f73f5b20 00001002 c7337b50 f8091f6d f8099a4d f80994e4
00000003 00000000 c7337b68 00000000 c67e4400 00001000 c7337b80 f80935e5
00000000 00000000 00000000 00000000 e1fcf000 0000000f e59be618 c70bf900
Call Trace:
[<f8091f6d>] logfs_get_write_page.clone.16+0xdd/0x100 [logfs]
[<f80935e5>] logfs_mod_segment_entry+0x55/0x110 [logfs]
[<f809460d>] logfs_get_segment_entry+0x1d/0x20 [logfs]
[<f8091060>] ? logfs_cleanup_journal+0x50/0x50 [logfs]
[<f809521b>] ostore_get_erase_count+0x1b/0x40 [logfs]
[<f80965b8>] logfs_open_area+0xc8/0x150 [logfs]
[<c141a7ec>] ? kmemleak_alloc+0x2c/0x60
[<f809668e>] __logfs_segment_write.clone.16+0x4e/0x1b0 [logfs]
[<c10dd563>] ? mempool_kmalloc+0x13/0x20
[<c10dd563>] ? mempool_kmalloc+0x13/0x20
[<f809696f>] logfs_segment_write+0x17f/0x1d0 [logfs]
[<f8092e8c>] logfs_write_i0+0x11c/0x180 [logfs]
[<f8092f35>] logfs_write_direct+0x45/0x90 [logfs]
[<f80934cd>] __logfs_write_buf+0xbd/0xf0 [logfs]
[<c102900e>] ? kmap_atomic_prot+0x4e/0xe0
[<f809424b>] logfs_write_buf+0x3b/0x60 [logfs]
[<f80947a9>] __logfs_write_inode+0xa9/0x110 [logfs]
[<f8094cb0>] logfs_rewrite_block+0xc0/0x110 [logfs]
[<f8095300>] ? get_mapping_page+0x10/0x60 [logfs]
[<f8095aa0>] ? logfs_load_object_aliases+0x2e0/0x2f0 [logfs]
[<f808e57d>] logfs_gc_segment+0x2ad/0x310 [logfs]
[<f808e62a>] __logfs_gc_once+0x4a/0x80 [logfs]
[<f808ed43>] logfs_gc_pass+0x683/0x6a0 [logfs]
[<f8097a89>] logfs_mount+0x5a9/0x680 [logfs]
[<c1126b21>] mount_fs+0x21/0xd0
[<c10f6f6f>] ? __alloc_percpu+0xf/0x20
[<c113da41>] ? alloc_vfsmnt+0xb1/0x130
[<c113db4b>] vfs_kern_mount+0x4b/0xa0
[<c113e06e>] do_kern_mount+0x3e/0xe0
[<c113f60d>] do_mount+0x34d/0x670
[<c10f2749>] ? strndup_user+0x49/0x70
[<c113fcab>] sys_mount+0x6b/0xa0
[<c142d87c>] syscall_call+0x7/0xb
Code: f8 e8 8b 93 39 c9 8b 45 f8 3e 0f ba 28 00 19 d2 85 d2 74 ca eb d0 0f 0b 8d 45 fc 89 44 24 04 c7 04 24 3d 9a 09 f8 e8 09 92 39 c9 <0f> 0b 8d 74 26 00 55 89 e5 3e 8d 74 26 00 8b 10 80 e6 01 74 09
EIP: [<f809132a>] logfs_lock_write_page+0x6a/0x70 [logfs] SS:ESP 0068:c7337b18
---[ end trace 96e67d5b3aa3d6ca ]---

The patch passes locked page to __logfs_write_inode. It calls function
logfs_get_wblocks() to pre-lock the page. This ensures any further
attempts to lock the page are ignored (esp from get_erase_count).

Acked-by: Joern Engel <joern@logfs.org>
Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
logfs: set superblock shutdown flag after generic sb shutdown 2012-01-28T06:07:47+00:00 Prasad Joshi prasadjoshi.linux@gmail.com 2011-10-30T16:45:32+00:00 ecfd890991a26e70547e025673580923a004c5e4 While unmounting the file system LogFS calls generic_shutdown_super. The function does file system independent superblock shutdown. However, it might result in call file system specific inode eviction. LogFS marks FS shutting down by setting bit LOGFS_SB_FLAG_SHUTDOWN in super->s_flags. Since, inode eviction might call truncate on inode, following BUG is observed when file system is unmounted: ------------[ cut here ]------------ kernel BUG at /home/prasad/logfs/segment.c:362! invalid opcode: 0000 [#1] PREEMPT SMP CPU 3 Modules linked in: logfs binfmt_misc ppdev virtio_blk parport_pc lp parport psmouse floppy virtio_pci serio_raw virtio_ring virtio Pid: 1933, comm: umount Not tainted 3.0.0+ #4 Bochs Bochs RIP: 0010:[<ffffffffa008c841>] [<ffffffffa008c841>] logfs_segment_write+0x211/0x230 [logfs] RSP: 0018:ffff880062d7b9e8 EFLAGS: 00010202 RAX: 000000000000000e RBX: ffff88006eca9000 RCX: 0000000000000000 RDX: ffff88006fd87c40 RSI: ffffea00014ff468 RDI: ffff88007b68e000 RBP: ffff880062d7ba48 R08: 8000000020451430 R09: 0000000000000000 R10: dead000000100100 R11: 0000000000000000 R12: ffff88006fd87c40 R13: ffffea00014ff468 R14: ffff88005ad0a460 R15: 0000000000000000 FS: 00007f25d50ea760(0000) GS:ffff88007fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000d05e48 CR3: 0000000062c72000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process umount (pid: 1933, threadinfo ffff880062d7a000, task ffff880070b44500) Stack: ffff880062d7ba38 ffff88005ad0a508 0000000000001000 0000000000000000 8000000020451430 ffffea00014ff468 ffff880062d7ba48 ffff88005ad0a460 ffff880062d7bad8 ffffea00014ff468 ffff88006fd87c40 0000000000000000 Call Trace: [<ffffffffa0088fee>] logfs_write_i0+0x12e/0x190 [logfs] [<ffffffffa0089360>] __logfs_write_rec+0x140/0x220 [logfs] [<ffffffffa0089312>] __logfs_write_rec+0xf2/0x220 [logfs] [<ffffffffa00894a4>] logfs_write_rec+0x64/0xd0 [logfs] [<ffffffffa0089616>] __logfs_write_buf+0x106/0x110 [logfs] [<ffffffffa008a19e>] logfs_write_buf+0x4e/0x80 [logfs] [<ffffffffa008a6b8>] __logfs_write_inode+0x98/0x110 [logfs] [<ffffffffa008a7c4>] logfs_truncate+0x54/0x290 [logfs] [<ffffffffa008abfc>] logfs_evict_inode+0xdc/0x190 [logfs] [<ffffffff8115eef5>] evict+0x85/0x170 [<ffffffff8115f126>] iput+0xe6/0x1b0 [<ffffffff8115b4a8>] shrink_dcache_for_umount_subtree+0x218/0x280 [<ffffffff8115ce91>] shrink_dcache_for_umount+0x51/0x90 [<ffffffff8114796c>] generic_shutdown_super+0x2c/0x100 [<ffffffffa008cc47>] logfs_kill_sb+0x57/0xf0 [logfs] [<ffffffff81147de5>] deactivate_locked_super+0x45/0x70 [<ffffffff811487ea>] deactivate_super+0x4a/0x70 [<ffffffff81163934>] mntput_no_expire+0xa4/0xf0 [<ffffffff8116469f>] sys_umount+0x6f/0x380 [<ffffffff814dd46b>] system_call_fastpath+0x16/0x1b Code: 55 c8 49 8d b6 a8 00 00 00 45 89 f9 45 89 e8 4c 89 e1 4c 89 55 b8 c7 04 24 00 00 00 00 e8 68 fc ff ff 4c 8b 55 b8 e9 3c ff ff ff <0f> 0b 0f 0b c7 45 c0 00 00 00 00 e9 44 fe ff ff 66 66 66 66 66 RIP [<ffffffffa008c841>] logfs_segment_write+0x211/0x230 [logfs] RSP <ffff880062d7b9e8> ---[ end trace fe6b040cea952290 ]--- Therefore, move super->s_flags setting after the fs-indenpendent work has been finished. Reviewed-by: Joern Engel <joern@logfs.org> Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com> 
While unmounting the file system LogFS calls generic_shutdown_super.
The function does file system independent superblock shutdown.
However, it might result in call file system specific inode eviction.

LogFS marks FS shutting down by setting bit LOGFS_SB_FLAG_SHUTDOWN in
super->s_flags. Since, inode eviction might call truncate on inode,
following BUG is observed when file system is unmounted:

------------[ cut here ]------------
kernel BUG at /home/prasad/logfs/segment.c:362!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU 3
Modules linked in: logfs binfmt_misc ppdev virtio_blk parport_pc lp
	parport psmouse floppy virtio_pci serio_raw virtio_ring virtio

Pid: 1933, comm: umount Not tainted 3.0.0+ #4 Bochs Bochs
RIP: 0010:[<ffffffffa008c841>]  [<ffffffffa008c841>]
		logfs_segment_write+0x211/0x230 [logfs]
RSP: 0018:ffff880062d7b9e8  EFLAGS: 00010202
RAX: 000000000000000e RBX: ffff88006eca9000 RCX: 0000000000000000
RDX: ffff88006fd87c40 RSI: ffffea00014ff468 RDI: ffff88007b68e000
RBP: ffff880062d7ba48 R08: 8000000020451430 R09: 0000000000000000
R10: dead000000100100 R11: 0000000000000000 R12: ffff88006fd87c40
R13: ffffea00014ff468 R14: ffff88005ad0a460 R15: 0000000000000000
FS:  00007f25d50ea760(0000) GS:ffff88007fd80000(0000)
	knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000d05e48 CR3: 0000000062c72000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process umount (pid: 1933, threadinfo ffff880062d7a000,
	task ffff880070b44500)
Stack:
ffff880062d7ba38 ffff88005ad0a508 0000000000001000 0000000000000000
8000000020451430 ffffea00014ff468 ffff880062d7ba48 ffff88005ad0a460
ffff880062d7bad8 ffffea00014ff468 ffff88006fd87c40 0000000000000000
Call Trace:
[<ffffffffa0088fee>] logfs_write_i0+0x12e/0x190 [logfs]
[<ffffffffa0089360>] __logfs_write_rec+0x140/0x220 [logfs]
[<ffffffffa0089312>] __logfs_write_rec+0xf2/0x220 [logfs]
[<ffffffffa00894a4>] logfs_write_rec+0x64/0xd0 [logfs]
[<ffffffffa0089616>] __logfs_write_buf+0x106/0x110 [logfs]
[<ffffffffa008a19e>] logfs_write_buf+0x4e/0x80 [logfs]
[<ffffffffa008a6b8>] __logfs_write_inode+0x98/0x110 [logfs]
[<ffffffffa008a7c4>] logfs_truncate+0x54/0x290 [logfs]
[<ffffffffa008abfc>] logfs_evict_inode+0xdc/0x190 [logfs]
[<ffffffff8115eef5>] evict+0x85/0x170
[<ffffffff8115f126>] iput+0xe6/0x1b0
[<ffffffff8115b4a8>] shrink_dcache_for_umount_subtree+0x218/0x280
[<ffffffff8115ce91>] shrink_dcache_for_umount+0x51/0x90
[<ffffffff8114796c>] generic_shutdown_super+0x2c/0x100
[<ffffffffa008cc47>] logfs_kill_sb+0x57/0xf0 [logfs]
[<ffffffff81147de5>] deactivate_locked_super+0x45/0x70
[<ffffffff811487ea>] deactivate_super+0x4a/0x70
[<ffffffff81163934>] mntput_no_expire+0xa4/0xf0
[<ffffffff8116469f>] sys_umount+0x6f/0x380
[<ffffffff814dd46b>] system_call_fastpath+0x16/0x1b
Code: 55 c8 49 8d b6 a8 00 00 00 45 89 f9 45 89 e8 4c 89 e1 4c 89 55
b8 c7 04 24 00 00 00 00 e8 68 fc ff ff 4c 8b 55 b8 e9 3c ff ff ff <0f>
0b 0f 0b c7 45 c0 00 00 00 00 e9 44 fe ff ff 66 66 66 66 66
RIP  [<ffffffffa008c841>] logfs_segment_write+0x211/0x230 [logfs]
RSP <ffff880062d7b9e8>
---[ end trace fe6b040cea952290 ]---

Therefore, move super->s_flags setting after the fs-indenpendent work
has been finished.

Reviewed-by: Joern Engel <joern@logfs.org>
Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
logfs: take write mutex lock during fsync and sync 2012-01-28T06:06:06+00:00 Prasad Joshi prasadjoshi.linux@gmail.com 2012-01-28T06:06:06+00:00 13ced29cb28996a9bc4f68e43ff0c57eafdb1e21 LogFS uses super->s_write_mutex while writing data to disk. Taking the same mutex lock in sync and fsync code path solves the following BUG: ------------[ cut here ]------------ kernel BUG at /home/prasad/logfs/dev_bdev.c:134! Pid: 2387, comm: flush-253:16 Not tainted 3.0.0+ #4 Bochs Bochs RIP: 0010:[<ffffffffa007deed>] [<ffffffffa007deed>] bdev_writeseg+0x25d/0x270 [logfs] Call Trace: [<ffffffffa007c381>] logfs_open_area+0x91/0x150 [logfs] [<ffffffff8128dcb2>] ? find_level.clone.9+0x62/0x100 [<ffffffffa007c49c>] __logfs_segment_write.clone.20+0x5c/0x190 [logfs] [<ffffffff810ef005>] ? mempool_kmalloc+0x15/0x20 [<ffffffff810ef383>] ? mempool_alloc+0x53/0x130 [<ffffffffa007c7a4>] logfs_segment_write+0x1d4/0x230 [logfs] [<ffffffffa0078f8e>] logfs_write_i0+0x12e/0x190 [logfs] [<ffffffffa0079300>] __logfs_write_rec+0x140/0x220 [logfs] [<ffffffffa0079444>] logfs_write_rec+0x64/0xd0 [logfs] [<ffffffffa00795b6>] __logfs_write_buf+0x106/0x110 [logfs] [<ffffffffa007a13e>] logfs_write_buf+0x4e/0x80 [logfs] [<ffffffffa0073e33>] __logfs_writepage+0x23/0x80 [logfs] [<ffffffffa007410c>] logfs_writepage+0xdc/0x110 [logfs] [<ffffffff810f5ba7>] __writepage+0x17/0x40 [<ffffffff810f6208>] write_cache_pages+0x208/0x4f0 [<ffffffff810f5b90>] ? set_page_dirty+0x70/0x70 [<ffffffff810f653a>] generic_writepages+0x4a/0x70 [<ffffffff810f75d1>] do_writepages+0x21/0x40 [<ffffffff8116b9d1>] writeback_single_inode+0x101/0x250 [<ffffffff8116bdbd>] writeback_sb_inodes+0xed/0x1c0 [<ffffffff8116c5fb>] writeback_inodes_wb+0x7b/0x1e0 [<ffffffff8116cc23>] wb_writeback+0x4c3/0x530 [<ffffffff814d984d>] ? sub_preempt_count+0x9d/0xd0 [<ffffffff8116cd6b>] wb_do_writeback+0xdb/0x290 [<ffffffff814d984d>] ? sub_preempt_count+0x9d/0xd0 [<ffffffff814d6208>] ? _raw_spin_unlock_irqrestore+0x18/0x40 [<ffffffff8105aa5a>] ? del_timer+0x8a/0x120 [<ffffffff8116cfac>] bdi_writeback_thread+0x8c/0x2e0 [<ffffffff8116cf20>] ? wb_do_writeback+0x290/0x290 [<ffffffff8106d2e6>] kthread+0x96/0xa0 [<ffffffff814de514>] kernel_thread_helper+0x4/0x10 [<ffffffff8106d250>] ? kthread_worker_fn+0x190/0x190 [<ffffffff814de510>] ? gs_change+0xb/0xb RIP [<ffffffffa007deed>] bdev_writeseg+0x25d/0x270 [logfs] ---[ end trace 0211ad60a57657c4 ]--- Reviewed-by: Joern Engel <joern@logfs.org> Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com> 
LogFS uses super->s_write_mutex while writing data to disk. Taking the
same mutex lock in sync and fsync code path solves the following BUG:

------------[ cut here ]------------
kernel BUG at /home/prasad/logfs/dev_bdev.c:134!

Pid: 2387, comm: flush-253:16 Not tainted 3.0.0+ #4 Bochs Bochs
RIP: 0010:[<ffffffffa007deed>]  [<ffffffffa007deed>]
                bdev_writeseg+0x25d/0x270 [logfs]
Call Trace:
[<ffffffffa007c381>] logfs_open_area+0x91/0x150 [logfs]
[<ffffffff8128dcb2>] ? find_level.clone.9+0x62/0x100
[<ffffffffa007c49c>] __logfs_segment_write.clone.20+0x5c/0x190 [logfs]
[<ffffffff810ef005>] ? mempool_kmalloc+0x15/0x20
[<ffffffff810ef383>] ? mempool_alloc+0x53/0x130
[<ffffffffa007c7a4>] logfs_segment_write+0x1d4/0x230 [logfs]
[<ffffffffa0078f8e>] logfs_write_i0+0x12e/0x190 [logfs]
[<ffffffffa0079300>] __logfs_write_rec+0x140/0x220 [logfs]
[<ffffffffa0079444>] logfs_write_rec+0x64/0xd0 [logfs]
[<ffffffffa00795b6>] __logfs_write_buf+0x106/0x110 [logfs]
[<ffffffffa007a13e>] logfs_write_buf+0x4e/0x80 [logfs]
[<ffffffffa0073e33>] __logfs_writepage+0x23/0x80 [logfs]
[<ffffffffa007410c>] logfs_writepage+0xdc/0x110 [logfs]
[<ffffffff810f5ba7>] __writepage+0x17/0x40
[<ffffffff810f6208>] write_cache_pages+0x208/0x4f0
[<ffffffff810f5b90>] ? set_page_dirty+0x70/0x70
[<ffffffff810f653a>] generic_writepages+0x4a/0x70
[<ffffffff810f75d1>] do_writepages+0x21/0x40
[<ffffffff8116b9d1>] writeback_single_inode+0x101/0x250
[<ffffffff8116bdbd>] writeback_sb_inodes+0xed/0x1c0
[<ffffffff8116c5fb>] writeback_inodes_wb+0x7b/0x1e0
[<ffffffff8116cc23>] wb_writeback+0x4c3/0x530
[<ffffffff814d984d>] ? sub_preempt_count+0x9d/0xd0
[<ffffffff8116cd6b>] wb_do_writeback+0xdb/0x290
[<ffffffff814d984d>] ? sub_preempt_count+0x9d/0xd0
[<ffffffff814d6208>] ? _raw_spin_unlock_irqrestore+0x18/0x40
[<ffffffff8105aa5a>] ? del_timer+0x8a/0x120
[<ffffffff8116cfac>] bdi_writeback_thread+0x8c/0x2e0
[<ffffffff8116cf20>] ? wb_do_writeback+0x290/0x290
[<ffffffff8106d2e6>] kthread+0x96/0xa0
[<ffffffff814de514>] kernel_thread_helper+0x4/0x10
[<ffffffff8106d250>] ? kthread_worker_fn+0x190/0x190
[<ffffffff814de510>] ? gs_change+0xb/0xb
RIP  [<ffffffffa007deed>] bdev_writeseg+0x25d/0x270 [logfs]
---[ end trace 0211ad60a57657c4 ]---

Reviewed-by: Joern Engel <joern@logfs.org>
Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
logfs: Prevent memory corruption 2012-01-28T05:54:21+00:00 Joern Engel joern@logfs.org 2011-11-20T16:59:01+00:00 934eed395d201bf0901ca0c0cc3703b18729d0ce This is a bad one. I wonder whether we were so far protected by no_free_segments(sb) usually being smaller than LOGFS_NO_AREAS. Found by Dan Carpenter <dan.carpenter@oracle.com> using smatch. Signed-off-by: Joern Engel <joern@logfs.org> Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com> 
This is a bad one.  I wonder whether we were so far protected by
no_free_segments(sb) usually being smaller than LOGFS_NO_AREAS.

Found by Dan Carpenter <dan.carpenter@oracle.com> using smatch.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>