linux-toradex.git/fs, branch v3.8.2

xfs: xfs_bmap_add_attrfork_local is too generic

2013-03-03T22:03:40+00:00

commit 1e82379b018ceed0f0912327c60d73107dacbcb3 upstream.

When we are converting local data to an extent format as a result of
adding an attribute, the type of data contained in the local fork
determines the behaviour that needs to occur.

xfs_bmap_add_attrfork_local() already handles the directory data
case specially by using S_ISDIR() and calling out to
xfs_dir2_sf_to_block(), but with verifiers we now need to handle
each different type of metadata specially and different metadata
formats require different verifiers (and eventually block header
initialisation).

There is only a single place that we add and attribute fork to
the inode, but that is in the attribute code and it knows nothing
about the specific contents of the data fork. It is only the case of
local data that is the issue here, so adding code to hadnle this
case in the attribute specific code is wrong. Hence we are really
stuck trying to detect the data fork contents in
xfs_bmap_add_attrfork_local() and performing the correct callout
there.

Luckily the current cases can be determined by S_IS* macros, and we
can push the work off to data specific callouts, but each of those
callouts does a lot of work in common with
xfs_bmap_local_to_extents(). The only reason that this fails for
symlinks right now is is that xfs_bmap_local_to_extents() assumes
the data fork contains extent data, and so attaches a a bmap extent
data verifier to the buffer and simply copies the data fork
information straight into it.

To fix this, allow us to pass a "formatting" callback into
xfs_bmap_local_to_extents() which is responsible for setting the
buffer type, initialising it and copying the data fork contents over
to the new buffer. This allows callers to specify how they want to
format the new buffer (which is necessary for the upcoming CRC
enabled metadata blocks) and hence make xfs_bmap_local_to_extents()
useful for any type of data fork content.

Signed-off-by: Dave Chinner 
Reviewed-by: Mark Tinguely 
Signed-off-by: Ben Myers 
Signed-off-by: Greg Kroah-Hartman

pstore: Avoid deadlock in panic and emergency-restart path

2013-03-03T22:03:38+00:00

commit 9f244e9cfd70c7c0f82d3c92ce772ab2a92d9f64 upstream.

[Issue]

When pstore is in panic and emergency-restart paths, it may be blocked
in those paths because it simply takes spin_lock.

This is an example scenario which pstore may hang up in a panic path:

 - cpuA grabs psinfo->buf_lock
 - cpuB panics and calls smp_send_stop
 - smp_send_stop sends IRQ to cpuA
 - after 1 second, cpuB gives up on cpuA and sends an NMI instead
 - cpuA is now in an NMI handler while still holding buf_lock
 - cpuB is deadlocked

This case may happen if a firmware has a bug and
cpuA is stuck talking with it more than one second.

Also, this is a similar scenario in an emergency-restart path:

 - cpuA grabs psinfo->buf_lock and stucks in a firmware
 - cpuB kicks emergency-restart via either sysrq-b or hangcheck timer.
   And then, cpuB is deadlocked by taking psinfo->buf_lock again.

[Solution]

This patch avoids the deadlocking issues in both panic and emergency_restart
paths by introducing a function, is_non_blocking_path(), to check if a cpu
can be blocked in current path.

With this patch, pstore is not blocked even if another cpu has
taken a spin_lock, in those paths by changing from spin_lock_irqsave
to spin_trylock_irqsave.

In addition, according to a comment of emergency_restart() in kernel/sys.c,
spin_lock shouldn't be taken in an emergency_restart path to avoid
deadlock. This patch fits the comment below.


/**
 *      emergency_restart - reboot the system
 *
 *      Without shutting down any hardware or taking any locks
 *      reboot the system.  This is called when we know we are in
 *      trouble so this is our best effort to reboot.  This is
 *      safe to call in interrupt context.
 */
void emergency_restart(void)


Signed-off-by: Seiji Aguchi 
Acked-by: Don Zickus 
Signed-off-by: Tony Luck 
Cc: CAI Qian 
Signed-off-by: Greg Kroah-Hartman

fuse: don't WARN when nlink is zero

2013-03-03T22:03:38+00:00

commit dfca7cebc2679f3d129f8e680a8f199a7ad16e38 upstream.

drop_nlink() warns if nlink is already zero.  This is triggerable by a buggy
userspace filesystem.  The cure, I think, is worse than the disease so disable
the warning.

Reported-by: Tero Roponen 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

nfsd: Fix memleak

2013-03-03T22:03:37+00:00

commit 2d32b29a1c2830f7c42caa8258c714acd983961f upstream.

When free nfs-client, it must free the ->cl_stateids.

Signed-off-by: Jianpeng Ma 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

ext4: fix free clusters calculation in bigalloc filesystem

2013-03-03T22:03:37+00:00

commit 304e220f0879198b1f5309ad6f0be862b4009491 upstream.

ext4_has_free_clusters() should tell us whether there is enough free
clusters to allocate, however number of free clusters in the file system
is converted to blocks using EXT4_C2B() which is not only wrong use of
the macro (we should have used EXT4_NUM_B2C) but it's also completely
wrong concept since everything else is in cluster units.

Moreover when calculating number of root clusters we should be using
macro EXT4_NUM_B2C() instead of EXT4_B2C() otherwise the result might be
off by one. However r_blocks_count should always be a multiple of the
cluster ratio so doing a plain bit shift should be enough here. We
avoid using EXT4_B2C() because it's confusing.

As a result of the first problem number of free clusters is much bigger
than it should have been and ext4_has_free_clusters() would return 1 even
if there is really not enough free clusters available.

Fix this by removing the EXT4_C2B() conversion of free clusters and
using bit shift when calculating number of root clusters. This bug
affects number of xfstests tests covering file system ENOSPC situation
handling. With this patch most of the ENOSPC problems with bigalloc file
system disappear, especially the errors caused by delayed allocation not
having enough space when the actual allocation is finally requested.

Signed-off-by: Lukas Czerner 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: fix xattr block allocation/release with bigalloc

2013-03-03T22:03:37+00:00

commit 1231b3a1eb5740192aeebf5344dd6d6da000febf upstream.

Currently when new xattr block is created or released we we would call
dquot_free_block() or dquot_alloc_block() respectively, among the else
decrementing or incrementing the number of blocks assigned to the
inode by one block.

This however does not work for bigalloc file system because we always
allocate/free the whole cluster so we have to count with that in
dquot_free_block() and dquot_alloc_block() as well.

Use the clusters-to-blocks conversion EXT4_C2B() when passing number of
blocks to the dquot_alloc/free functions to fix the problem.

The problem has been revealed by xfstests #117 (and possibly others).

Signed-off-by: Lukas Czerner 
Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Eric Sandeen 
Signed-off-by: Greg Kroah-Hartman

ext4: fix race in ext4_mb_add_n_trim()

2013-03-03T22:03:37+00:00

commit f1167009711032b0d747ec89a632a626c901a1ad upstream.

In ext4_mb_add_n_trim(), lg_prealloc_lock should be taken when
changing the lg_prealloc_list.

Signed-off-by: Niu Yawei 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: release sysfs kobject when failing to enable quotas on mount

2013-03-03T22:03:37+00:00

commit 72ba74508b2857e71d65fc93f0d6b684492fc740 upstream.

In addition, print the error returned from ext4_enable_quotas()

Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Carlos Maiolino 
Signed-off-by: Greg Kroah-Hartman

ext4: check bh in ext4_read_block_bitmap()

2013-03-03T22:03:37+00:00

commit 15b49132fc972c63894592f218ea5a9a61b1a18f upstream.

Validate the bh pointer before using it, since
ext4_read_block_bitmap_nowait() might return NULL.

I've seen this in fsfuzz testing.

 EXT4-fs error (device loop0): ext4_read_block_bitmap_nowait:385: comm touch: Cannot get buffer for block bitmap - block_group = 0, block_bitmap = 3925999616
 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [] ext4_wait_block_bitmap+0x25/0xe0
 ...
 Call Trace:
  [] ext4_read_block_bitmap+0x35/0x60
  [] ext4_free_blocks+0x236/0xb80
  [] ? __getblk+0x36/0x70
  [] ? __find_get_block+0x8f/0x210
  [] ? kmem_cache_free+0x33/0x140
  [] ext4_xattr_release_block+0x1b5/0x1d0
  [] ext4_xattr_delete_inode+0xbe/0x100
  [] ext4_free_inode+0x7c/0x4d0
  [] ? ext4_mark_inode_dirty+0x88/0x230
  [] ext4_evict_inode+0x32c/0x490
  [] evict+0xa7/0x1c0
  [] iput_final+0xe3/0x170
  [] iput+0x3e/0x50
  [] ext4_add_nondir+0x4d/0x90
  [] ext4_create+0xeb/0x170
  [] vfs_create+0xac/0xd0
  [] lookup_open+0x185/0x1c0
  [] ? selinux_inode_permission+0xa9/0x170
  [] do_last+0x2d4/0x7a0
  [] path_openat+0xb3/0x480
  [] ? handle_mm_fault+0x251/0x3b0
  [] do_filp_open+0x49/0xa0
  [] ? __alloc_fd+0xdd/0x150
  [] do_sys_open+0x108/0x1f0
  [] sys_open+0x21/0x30
  [] system_call_fastpath+0x16/0x1b

Also fix comment for ext4_read_block_bitmap_nowait()

Signed-off-by: Eryu Guan 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: return ENOMEM if sb_getblk() fails

2013-03-03T22:03:36+00:00

commit 860d21e2c585f7ee8a4ecc06f474fdc33c9474f4 upstream.

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So ENOMEM is more appropriate than EIO.  In addition,
make sure that the file system is marked as being inconsistent if
sb_getblk() fails.

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman