linux-stable.git/fs/logfs/inode.c, branch linux-4.2.y Linux kernel stable tree Fix misspellings of "whether" in comments. 2012-11-19T13:31:35+00:00 Adam Buchbinder adam.buchbinder@gmail.com 2012-09-20T01:48:00+00:00 48fc7f7e787dd65ffe88521bce31f4062ba273eb "Whether" is misspelled in various comments across the tree; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> 
"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-03T03:25:04+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-10-03T03:25:04+00:00 aab174f0df5d72d31caccf281af5f614fa254578 Pull vfs update from Al Viro: - big one - consolidation of descriptor-related logics; almost all of that is moved to fs/file.c (BTW, I'm seriously tempted to rename the result to fd.c. As it is, we have a situation when file_table.c is about handling of struct file and file.c is about handling of descriptor tables; the reasons are historical - file_table.c used to be about a static array of struct file we used to have way back). A lot of stray ends got cleaned up and converted to saner primitives, disgusting mess in android/binder.c is still disgusting, but at least doesn't poke so much in descriptor table guts anymore. A bunch of relatively minor races got fixed in process, plus an ext4 struct file leak. - related thing - fget_light() partially unuglified; see fdget() in there (and yes, it generates the code as good as we used to have). - also related - bits of Cyrill's procfs stuff that got entangled into that work; _not_ all of it, just the initial move to fs/proc/fd.c and switch of fdinfo to seq_file. - Alex's fs/coredump.c spiltoff - the same story, had been easier to take that commit than mess with conflicts. The rest is a separate pile, this was just a mechanical code movement. - a few misc patches all over the place. Not all for this cycle, there'll be more (and quite a few currently sit in akpm's tree)." Fix up trivial conflicts in the android binder driver, and some fairly simple conflicts due to two different changes to the sock_alloc_file() interface ("take descriptor handling from sock_alloc_file() to callers" vs "net: Providing protocol type via system.sockprotoname xattr of /proc/PID/fd entries" adding a dentry name to the socket) * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits) MAX_LFS_FILESIZE should be a loff_t compat: fs: Generic compat_sys_sendfile implementation fs: push rcu_barrier() from deactivate_locked_super() to filesystems btrfs: reada_extent doesn't need kref for refcount coredump: move core dump functionality into its own file coredump: prevent double-free on an error path in core dumper usb/gadget: fix misannotations fcntl: fix misannotations ceph: don't abuse d_delete() on failure exits hypfs: ->d_parent is never NULL or negative vfs: delete surplus inode NULL check switch simple cases of fget_light to fdget new helpers: fdget()/fdput() switch o2hb_region_dev_write() to fget_light() proc_map_files_readdir(): don't bother with grabbing files make get_file() return its argument vhost_set_vring(): turn pollstart/pollstop into bool switch prctl_set_mm_exe_file() to fget_light() switch xfs_find_handle() to fget_light() switch xfs_swapext() to fget_light() ... 
Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...
fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-03T01:35:55+00:00 Kirill A. Shutemov kirill.shutemov@linux.intel.com 2012-09-26T01:33:07+00:00 8c0a85377048b64c880e76ec7368904fe46d0b94 There's no reason to call rcu_barrier() on every deactivate_locked_super(). We only need to make sure that all delayed rcu free inodes are flushed before we destroy related cache. Removing rcu_barrier() from deactivate_locked_super() affects some fast paths. E.g. on my machine exit_group() of a last process in IPC namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-10-02T18:11:09+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-10-02T18:11:09+00:00 437589a74b6a590d175f86cf9f7b2efcee7765e7 Pull user namespace changes from Eric Biederman: "This is a mostly modest set of changes to enable basic user namespace support. This allows the code to code to compile with user namespaces enabled and removes the assumption there is only the initial user namespace. Everything is converted except for the most complex of the filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs, nfs, ocfs2 and xfs as those patches need a bit more review. The strategy is to push kuid_t and kgid_t values are far down into subsystems and filesystems as reasonable. Leaving the make_kuid and from_kuid operations to happen at the edge of userspace, as the values come off the disk, and as the values come in from the network. Letting compile type incompatible compile errors (present when user namespaces are enabled) guide me to find the issues. The most tricky areas have been the places where we had an implicit union of uid and gid values and were storing them in an unsigned int. Those places were converted into explicit unions. I made certain to handle those places with simple trivial patches. Out of that work I discovered we have generic interfaces for storing quota by projid. I had never heard of the project identifiers before. Adding full user namespace support for project identifiers accounts for most of the code size growth in my git tree. Ultimately there will be work to relax privlige checks from "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing root in a user names to do those things that today we only forbid to non-root users because it will confuse suid root applications. While I was pushing kuid_t and kgid_t changes deep into the audit code I made a few other cleanups. I capitalized on the fact we process netlink messages in the context of the message sender. I removed usage of NETLINK_CRED, and started directly using current->tty. Some of these patches have also made it into maintainer trees, with no problems from identical code from different trees showing up in linux-next. After reading through all of this code I feel like I might be able to win a game of kernel trivial pursuit." Fix up some fairly trivial conflicts in netfilter uid/git logging code. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits) userns: Convert the ufs filesystem to use kuid/kgid where appropriate userns: Convert the udf filesystem to use kuid/kgid where appropriate userns: Convert ubifs to use kuid/kgid userns: Convert squashfs to use kuid/kgid where appropriate userns: Convert reiserfs to use kuid and kgid where appropriate userns: Convert jfs to use kuid/kgid where appropriate userns: Convert jffs2 to use kuid and kgid where appropriate userns: Convert hpfs to use kuid and kgid where appropriate userns: Convert btrfs to use kuid/kgid where appropriate userns: Convert bfs to use kuid/kgid where appropriate userns: Convert affs to use kuid/kgid wherwe appropriate userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids userns: On ia64 deal with current_uid and current_gid being kuid and kgid userns: On ppc convert current_uid from a kuid before printing. userns: Convert s390 getting uid and gid system calls to use kuid and kgid userns: Convert s390 hypfs to use kuid and kgid where appropriate userns: Convert binder ipc to use kuids userns: Teach security_path_chown to take kuids and kgids userns: Add user namespace support to IMA userns: Convert EVM to deal with kuids and kgids in it's hmac computation ... 
Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...
userns: Convert logfs to use kuid/kgid where appropriate 2012-09-21T10:13:13+00:00 Eric W. Biederman ebiederm@xmission.com 2012-02-10T19:41:28+00:00 1a0a994ebe851206d02469782da6c1f9a0547d7d Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> 
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
logfs: maintain the ordering of meta-inode destruction 2012-07-23T04:05:52+00:00 Prasad Joshi prasadjoshi.linux@gmail.com 2012-07-23T04:05:52+00:00 41b93bc1ee7e7276db698dd66afa7b740cda517a LogFS does not use a specialized area to maintain the inodes. The inodes information is kept in a specialized file called inode file. Similarly, the segment information is kept in a segment file. Since the segment file also has an inode which is kept in the inode file, the inode for segment file must be evicted before the inode for inode file. The change fixes the following BUG during unmount Pid: 2057, comm: umount Not tainted 3.5.0-rc6+ #25 Bochs Bochs RIP: 0010:[<ffffffffa005c5f2>] [<ffffffffa005c5f2>] move_page_to_btree+0x32/0x1f0 [logfs] Process umount (pid: 2057, threadinfo ...) Call Trace: [<ffffffff8112adca>] ? find_get_pages+0x2a/0x180 [<ffffffffa00549f5>] logfs_invalidatepage+0x85/0x90 [logfs] [<ffffffff81136c51>] truncate_inode_page+0xb1/0xd0 [<ffffffff81136dcf>] truncate_inode_pages_range+0x15f/0x490 [<ffffffff81558549>] ? printk+0x78/0x7a [<ffffffff81137185>] truncate_inode_pages+0x15/0x20 [<ffffffffa005b7fc>] logfs_evict_inode+0x6c/0x190 [logfs] [<ffffffff8155c75b>] ? _raw_spin_unlock+0x2b/0x40 [<ffffffff8119e3d7>] evict+0xa7/0x1b0 [<ffffffff8119ea6e>] dispose_list+0x3e/0x60 [<ffffffff8119f1c4>] evict_inodes+0xf4/0x110 [<ffffffff81185b53>] generic_shutdown_super+0x53/0xf0 [<ffffffffa005d8f2>] logfs_kill_sb+0x52/0xf0 [logfs] [<ffffffff81185ec5>] deactivate_locked_super+0x45/0x80 [<ffffffff81186a4a>] deactivate_super+0x4a/0x70 [<ffffffff811a228e>] mntput_no_expire+0xde/0x140 [<ffffffff811a30ff>] sys_umount+0x6f/0x3a0 [<ffffffff8155d8e9>] system_call_fastpath+0x16/0x1b ---[ end trace 45f7752082cefafd ]--- Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com> 
LogFS does not use a specialized area to maintain the inodes. The
inodes information is kept in a specialized file called inode file.
Similarly, the segment information is kept in a segment file. Since
the segment file also has an inode which is kept in the inode file,
the inode for segment file must be evicted before the inode for inode
file. The change fixes the following BUG during unmount

Pid: 2057, comm: umount Not tainted 3.5.0-rc6+ #25 Bochs Bochs
RIP: 0010:[<ffffffffa005c5f2>]  [<ffffffffa005c5f2>] move_page_to_btree+0x32/0x1f0 [logfs]
Process umount (pid: 2057, threadinfo ...)
Call Trace:
[<ffffffff8112adca>] ? find_get_pages+0x2a/0x180
[<ffffffffa00549f5>] logfs_invalidatepage+0x85/0x90 [logfs]
[<ffffffff81136c51>] truncate_inode_page+0xb1/0xd0
[<ffffffff81136dcf>] truncate_inode_pages_range+0x15f/0x490
[<ffffffff81558549>] ? printk+0x78/0x7a
[<ffffffff81137185>] truncate_inode_pages+0x15/0x20
[<ffffffffa005b7fc>] logfs_evict_inode+0x6c/0x190 [logfs]
[<ffffffff8155c75b>] ? _raw_spin_unlock+0x2b/0x40
[<ffffffff8119e3d7>] evict+0xa7/0x1b0
[<ffffffff8119ea6e>] dispose_list+0x3e/0x60
[<ffffffff8119f1c4>] evict_inodes+0xf4/0x110
[<ffffffff81185b53>] generic_shutdown_super+0x53/0xf0
[<ffffffffa005d8f2>] logfs_kill_sb+0x52/0xf0 [logfs]
[<ffffffff81185ec5>] deactivate_locked_super+0x45/0x80
[<ffffffff81186a4a>] deactivate_super+0x4a/0x70
[<ffffffff811a228e>] mntput_no_expire+0xde/0x140
[<ffffffff811a30ff>] sys_umount+0x6f/0x3a0
[<ffffffff8155d8e9>] system_call_fastpath+0x16/0x1b
---[ end trace 45f7752082cefafd ]---

Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
logfs: destroy the reserved inodes while unmounting 2012-04-02T03:50:33+00:00 Prasad Joshi prasadjoshi.linux@gmail.com 2012-03-09T00:57:12+00:00 d2dcd9083f101584e029cbd4f0e1a4e573170d43 We were assuming that the evict_inode() would never be called on reserved inodes. However, (after the commit 8e22c1a4e logfs: get rid of magical inodes) while unmounting the file system, in put_super, we call iput() on all of the reserved inodes. The following simple test used to cause a kernel panic on LogFS: 1. Mount a LogFS file system on /mnt 2. Create a file $ touch /mnt/a 3. Try to unmount the FS $ umount /mnt The simple fix would be to drop the assumption and properly destroy the reserved inodes. Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com> 
We were assuming that the evict_inode() would never be called on
reserved inodes. However, (after the commit 8e22c1a4e logfs: get rid
of magical inodes) while unmounting the file system, in put_super, we
call iput() on all of the reserved inodes.

The following simple test used to cause a kernel panic on LogFS:

1. Mount a LogFS file system on /mnt

2. Create a file
   $ touch /mnt/a

3. Try to unmount the FS
   $ umount /mnt

The simple fix would be to drop the assumption and properly destroy
the reserved inodes.

Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
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: 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: 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>