linux-toradex.git/fs/nilfs2, branch v3.0.63

nilfs2: fix fix very long mount time issue

2013-02-11T16:16:47+00:00

commit a9bae189542e71f91e61a4428adf6e5a7dfe8063 upstream.

There exists a situation when GC can work in background alone without
any other filesystem activity during significant time.

The nilfs_clean_segments() method calls nilfs_segctor_construct() that
updates superblocks in the case of NILFS_SC_SUPER_ROOT and
THE_NILFS_DISCONTINUED flags are set.  But when GC is working alone the
nilfs_clean_segments() is called with unset THE_NILFS_DISCONTINUED flag.
As a result, the update of superblocks doesn't occurred all this time
and in the case of SPOR superblocks keep very old values of last super
root placement.

SYMPTOMS:

Trying to mount a NILFS2 volume after SPOR in such environment ends with
very long mounting time (it can achieve about several hours in some
cases).

REPRODUCING PATH:

1. It needs to use external USB HDD, disable automount and doesn't
   make any additional filesystem activity on the NILFS2 volume.

2. Generate temporary file with size about 100 - 500 GB (for example,
   dd if=/dev/zero of= bs=1073741824 count=200).  The size of
   file defines duration of GC working.

3. Then it needs to delete file.

4. Start GC manually by means of command "nilfs-clean -p 0".  When you
   start GC by means of such way then, at the end, superblocks is updated
   by once.  So, for simulation of SPOR, it needs to wait sometime (15 -
   40 minutes) and simply switch off USB HDD manually.

5. Switch on USB HDD again and try to mount NILFS2 volume.  As a
   result, NILFS2 volume will mount during very long time.

REPRODUCIBILITY: 100%

FIX:

This patch adds checking that superblocks need to update and set
THE_NILFS_DISCONTINUED flag before nilfs_clean_segments() call.

Reported-by: Sergey Alexandrov 
Signed-off-by: Vyacheslav Dubeyko 
Tested-by: Vyacheslav Dubeyko 
Acked-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix deadlock issue between chcp and thaw ioctls

2012-08-15T19:04:10+00:00

commit 572d8b3945a31bee7c40d21556803e4807fd9141 upstream.

An fs-thaw ioctl causes deadlock with a chcp or mkcp -s command:

 chcp            D ffff88013870f3d0     0  1325   1324 0x00000004
 ...
 Call Trace:
   nilfs_transaction_begin+0x11c/0x1a0 [nilfs2]
   wake_up_bit+0x20/0x20
   copy_from_user+0x18/0x30 [nilfs2]
   nilfs_ioctl_change_cpmode+0x7d/0xcf [nilfs2]
   nilfs_ioctl+0x252/0x61a [nilfs2]
   do_page_fault+0x311/0x34c
   get_unmapped_area+0x132/0x14e
   do_vfs_ioctl+0x44b/0x490
   __set_task_blocked+0x5a/0x61
   vm_mmap_pgoff+0x76/0x87
   __set_current_blocked+0x30/0x4a
   sys_ioctl+0x4b/0x6f
   system_call_fastpath+0x16/0x1b
 thaw            D ffff88013870d890     0  1352   1351 0x00000004
 ...
 Call Trace:
   rwsem_down_failed_common+0xdb/0x10f
   call_rwsem_down_write_failed+0x13/0x20
   down_write+0x25/0x27
   thaw_super+0x13/0x9e
   do_vfs_ioctl+0x1f5/0x490
   vm_mmap_pgoff+0x76/0x87
   sys_ioctl+0x4b/0x6f
   filp_close+0x64/0x6c
   system_call_fastpath+0x16/0x1b

where the thaw ioctl deadlocked at thaw_super() when called while chcp was
waiting at nilfs_transaction_begin() called from
nilfs_ioctl_change_cpmode().  This deadlock is 100% reproducible.

This is because nilfs_ioctl_change_cpmode() first locks sb->s_umount in
read mode and then waits for unfreezing in nilfs_transaction_begin(),
whereas thaw_super() locks sb->s_umount in write mode.  The locking of
sb->s_umount here was intended to make snapshot mounts and the downgrade
of snapshots to checkpoints exclusive.

This fixes the deadlock issue by replacing the sb->s_umount usage in
nilfs_ioctl_change_cpmode() with a dedicated mutex which protects snapshot
mounts.

Signed-off-by: Ryusuke Konishi 
Cc: Fernando Luis Vazquez Cao 
Tested-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nilfs2: ensure proper cache clearing for gc-inodes

2012-07-16T15:47:38+00:00

commit fbb24a3a915f105016f1c828476be11aceac8504 upstream.

A gc-inode is a pseudo inode used to buffer the blocks to be moved by
garbage collection.

Block caches of gc-inodes must be cleared every time a garbage collection
function (nilfs_clean_segments) completes.  Otherwise, stale blocks
buffered in the caches may be wrongly reused in successive calls of the GC
function.

For user files, this is not a problem because their gc-inodes are
distinguished by a checkpoint number as well as an inode number.  They
never buffer different blocks if either an inode number, a checkpoint
number, or a block offset differs.

However, gc-inodes of sufile, cpfile and DAT file can store different data
for the same block offset.  Thus, the nilfs_clean_segments function can
move incorrect block for these meta-data files if an old block is cached.
I found this is really causing meta-data corruption in nilfs.

This fixes the issue by ensuring cache clear of gc-inodes and resolves
reported GC problems including checkpoint file corruption, b-tree
corruption, and the following warning during GC.

  nilfs_palloc_freev: entry number 307234 already freed.
  ...

Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix NULL pointer dereference in nilfs_load_super_block()

2012-03-23T18:20:50+00:00

commit d7178c79d9b7c5518f9943188091a75fc6ce0675 upstream.

According to the report from Slicky Devil, nilfs caused kernel oops at
nilfs_load_super_block function during mount after he shrank the
partition without resizing the filesystem:

 BUG: unable to handle kernel NULL pointer dereference at 00000048
 IP: [] nilfs_load_super_block+0x17e/0x280 [nilfs2]
 *pde = 00000000
 Oops: 0000 [#1] PREEMPT SMP
 ...
 Call Trace:
  [] init_nilfs+0x4b/0x2e0 [nilfs2]
  [] nilfs_mount+0x447/0x5b0 [nilfs2]
  [] mount_fs+0x36/0x180
  [] vfs_kern_mount+0x51/0xa0
  [] do_kern_mount+0x3e/0xe0
  [] do_mount+0x169/0x700
  [] sys_mount+0x6b/0xa0
  [] sysenter_do_call+0x12/0x28
 Code: 53 18 8b 43 20 89 4b 18 8b 4b 24 89 53 1c 89 43 24 89 4b 20 8b 43
 20 c7 43 2c 00 00 00 00 23 75 e8 8b 50 68 89 53 28 8b 54 b3 20 <8b> 72
 48 8b 7a 4c 8b 55 08 89 b3 84 00 00 00 89 bb 88 00 00 00
 EIP: [] nilfs_load_super_block+0x17e/0x280 [nilfs2] SS:ESP 0068:ca9bbdcc
 CR2: 0000000000000048

This turned out due to a defect in an error path which runs if the
calculated location of the secondary super block was invalid.

This patch fixes it and eliminates the reported oops.

Reported-by: Slicky Devil 
Signed-off-by: Ryusuke Konishi 
Tested-by: Slicky Devil 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nilfs2: unbreak compat ioctl

2012-01-06T22:13:52+00:00

commit 695c60f21c69e525a89279a5f35bae4ff237afbc upstream.

commit 828b1c50ae ("nilfs2: add compat ioctl") incidentally broke all
other NILFS compat ioctls.  Make them work again.

Signed-off-by: Thomas Meyer 
Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nilfs2_permission() doesn't need to bail out in RCU mode

2011-06-20T14:44:33+00:00

Nothing blocking except for generic_permission().  Which will DTRT.

Signed-off-by: Al Viro

nilfs2: fix problem in setting checkpoint interval

2011-06-11T06:51:15+00:00

Checkpoint generation interval of nilfs goes wrong after user has
changed the interval parameter with nilfs-tune tool.

 segctord starting. Construction interval = 5 seconds,
 CP frequency < 30 seconds
 segctord starting. Construction interval = 0 seconds,
 CP frequency < 30 seconds

This turned out to be caused by a trivial bug in initialization code
of log writer.  This will fix it.

Reported-by: Andrea Gelmini 
Signed-off-by: Ryusuke Konishi

nilfs2: fix missing block address termination in btree node shrinking

2011-06-11T06:51:15+00:00

nilfs_btree_delete function does not terminate part of virtual block
addresses when shrinking the last remaining child node into the root
node.  The missing address termination causes that dead btree node
blocks persist and chip away free disk space.

This fixes the leak bug on the btree node deletion.

Signed-off-by: Ryusuke Konishi

nilfs2: fix incorrect block address termination in node concatenation

2011-06-11T06:51:15+00:00

nilfs_btree_delete function wrongly terminates virtual block address
of the btree node held by its parent at index 0.  When concatenating
the index-0 node with its right sibling node, nilfs_btree_delete
terminates the block address of index-0 node instead of the right
sibling node which should be deleted.

This bug not only wears disk space in the long run, but also causes
file system corruption.  This will fix it.

Signed-off-by: Ryusuke Konishi

nilfs2: remove unnecessary dentry_unhash from rmdir, dir rename

2011-05-28T05:02:51+00:00

nilfs2 does not have problems with references to unlinked directories.

CC: KONISHI Ryusuke 
CC: linux-nilfs@vger.kernel.org
Signed-off-by: Sage Weil 
Signed-off-by: Al Viro