Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

It is useful to know how we got to the checking function when
hunting the bugs.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Do not forget to check whether lpt debugging is enabled before
running the check functions. This commit also makes some spelling
fixes.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We need to have a possibility to see various UBIFS variables
and ask UBIFS to dump various information. Debugfs is what
we need.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Introduce a new data structure which contains all debugging
stuff inside. This is cleaner than having debugging stuff
directly in 'c'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

I have a habit of compiling kernel with
EXTRA_CFLAGS="-Wextra -Wno-unused -Wno-sign-compare -Wno-missing-field-initializers"
and so fs/ubifs/key.h give lots (~10) of these every time:

CC      fs/ubifs/tnc_misc.o
In file included from fs/ubifs/ubifs.h:1725,
from fs/ubifs/tnc_misc.c:30:
fs/ubifs/key.h: In function 'key_r5_hash':
fs/ubifs/key.h:64: warning: comparison of unsigned expression >= 0 is always true
fs/ubifs/key.h: In function 'key_test_hash':
fs/ubifs/key.h:81: warning: comparison of unsigned expression >= 0 is always true

This patch fixes the warnings.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

It is very handy to be able to change default UBIFS compressor
via mount options. Introduce -o compr=<name> mount option support.
Currently only "none", "lzo" and "zlib" compressors are supported.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Save a 4 bytes of RAM per 'struct inode' by stroring inode
compression type in bit-filed, instead of using 'int'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

If data does not compress, it is better to leave it uncompressed
because we'll read it faster then. So do not compress data if we
save less than 64 bytes.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

To avoid memory allocation failure during bulk-read, pre-allocate
a bulk-read buffer, so that if there is only one bulk-reader at
a time, it would just use the pre-allocated buffer and would not
do any memory allocation. However, if there are more than 1 bulk-
reader, then only one reader would use the pre-allocated buffer,
while the other reader would allocate the buffer for itself.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Bulk-read allocates 128KiB or more using kmalloc. The allocation
starts failing often when the memory gets fragmented. UBIFS still
works fine in this case, because it falls-back to standard
(non-optimized) read method, though. This patch teaches bulk-read
to allocate exactly the amount of memory it needs, instead of
allocating 128KiB every time.

This patch is also a preparation to the further fix where we'll
have a pre-allocated bulk-read buffer as well. For example, now
the @bu object is prepared in 'ubifs_bulk_read()', so we could
path either pre-allocated or allocated information to
'ubifs_do_bulk_read()' later. Or teaching 'ubifs_do_bulk_read()'
not to allocate 'bu->buf' if it is already there.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Bulk-read allocates a lot of memory with 'kmalloc()', and when it
is/gets fragmented 'kmalloc()' fails with a scarry warning. But
because bulk-read is just an optimization, UBIFS keeps working fine.
Supress the warning by passing __GFP_NOWARN option to 'kmalloc()'.

This patch also introduces a macro for the magic 128KiB constant.
This is just neater.

Note, this is not really fixes the problem we had, but just hides
the warnings. The further patches fix the problem.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The LPT may have gaps in it because initially empty LEBs
are not added by mkfs.ubifs - because it does not know how
many there are.  Then UBIFS allocates empty LEBs in the
reverse order that they are discovered i.e. they are
added to, and removed from, the front of a list.  That
creates a gap in the middle of the LPT.

The function dirtying the LPT tree (for the purpose of
small model garbage collection) assumed that a gap could
only occur at the very end of the LPT and stopped dirtying
prematurely, which in turn resulted in the LPT running
out of space - something that is designed to be impossible.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

We print 'ino_t' type using '%lu' printk() placeholder, but this
results in many warnings when compiling for Alpha platform. Fix
this by adding (unsingned long) casts.

Fixes these warnings:

fs/ubifs/journal.c:693: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/journal.c:1131: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/dir.c:163: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/tnc.c:2680: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/tnc.c:2700: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/replay.c:1066: warning: format '%lu' expects type 'long unsigned int', but argument 7 has type 'ino_t'
fs/ubifs/orphan.c:108: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:135: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:142: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:154: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:159: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:451: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:539: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:612: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:843: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/orphan.c:856: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1438: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1443: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1475: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/recovery.c:1495: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:105: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:105: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:110: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:110: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:114: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:114: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:118: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:118: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'ino_t'
fs/ubifs/debug.c:1591: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1671: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1674: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1680: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1699: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1788: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1821: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1833: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:1924: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1932: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1938: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1945: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1953: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1960: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1967: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1973: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1988: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'ino_t'
fs/ubifs/debug.c:1991: warning: format '%lu' expects type 'long unsigned int', but argument 5 has type 'ino_t'
fs/ubifs/debug.c:2009: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'ino_t'
Reported-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Noticed by sparse:
fs/ubifs/file.c:75:2: warning: restricted __le64 degrades to integer
fs/ubifs/file.c:629:4: warning: restricted __le64 degrades to integer
fs/ubifs/dir.c:431:3: warning: restricted __le64 degrades to integer

This should be checked to ensure the ubifs_assert is working as
intended, I've done the suggested annotation in this patch.

fs/ubifs/sb.c:298:6: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:298:6:    expected int [signed] [assigned] tmp
fs/ubifs/sb.c:298:6:    got restricted __le64 [usertype] <noident>
fs/ubifs/sb.c:299:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:299:19:    expected restricted __le64 [usertype] atime_sec
fs/ubifs/sb.c:299:19:    got int [signed] [assigned] tmp
fs/ubifs/sb.c:300:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:300:19:    expected restricted __le64 [usertype] ctime_sec
fs/ubifs/sb.c:300:19:    got int [signed] [assigned] tmp
fs/ubifs/sb.c:301:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:301:19:    expected restricted __le64 [usertype] mtime_sec
fs/ubifs/sb.c:301:19:    got int [signed] [assigned] tmp

This looks like a bugfix as your tmp was a u32 so there was truncation in
the atime, mtime, ctime value, probably not intentional, add a tmp_le64
and use it here.

fs/ubifs/key.h:348:9: warning: cast to restricted __le32
fs/ubifs/key.h:348:9: warning: cast to restricted __le32
fs/ubifs/key.h:419:9: warning: cast to restricted __le32

Read from the annotated union member instead.

fs/ubifs/recovery.c:175:13: warning: incorrect type in assignment (different base types)
fs/ubifs/recovery.c:175:13:    expected unsigned int [unsigned] [usertype] save_flags
fs/ubifs/recovery.c:175:13:    got restricted __le32 [usertype] flags
fs/ubifs/recovery.c:186:13: warning: incorrect type in assignment (different base types)
fs/ubifs/recovery.c:186:13:    expected restricted __le32 [usertype] flags
fs/ubifs/recovery.c:186:13:    got unsigned int [unsigned] [usertype] save_flags

Do byteshifting at compile time of the flag value.  Annotate the saved_flags
as le32.

fs/ubifs/debug.c:368:10: warning: cast to restricted __le32
fs/ubifs/debug.c:368:10: warning: cast from restricted __le64

Should be checked if the truncation was intentional, I've changed the
printk to print the full width.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Remove the "UBIFS background thread ubifs_bgd0_0 started" message.
We kill the background thread when we switch to R/O mode, and
start it again whan we switch to R/W mode. OLPC is doing this
many times during boot, and we see this message many times as
well, which is irritating. So just kill the message.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Update the comment for ubifs_compress(), which incorrectly states that it
returnsa success/failure indicator.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

It is better to print "Reserved for root" than
"Reserved pool size", because it is more obvious for users
what this means.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Fixes the following Oops:

BUG: unable to handle kernel paging request at f8d24000
IP: [<f8ff0657>] :ubifs:ubifs_unpack_bits+0xcd/0x231
*pde = 34333067 *pte = 00000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: deflate zlib_deflate lzo lzo_decompress lzo_compress
ubifs ubi nandsim nand nand_ids nand_ecc mtd nfsd lockd sunrpc exportfs
[last unloaded: nand_ecc]

Pid: 7450, comm: sync Not tainted (2.6.27-rc8-ubifs-2.6 #27)
EIP: 0060:[<f8ff0657>] EFLAGS: 00010206 CPU: 0
EIP is at ubifs_unpack_bits+0xcd/0x231 [ubifs]
EAX: 00000000 EBX: 00000000 ECX: d7e43dc0 EDX: 0000ff00
ESI: 00000004 EDI: f8d23ffe EBP: d7e43db4 ESP: d7e43d8c
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process sync (pid: 7450, ti=d7e42000 task=eb6f9530 task.ti=d7e42000)
Stack: 00000400 c0103db4 dc5e8090 d7e43dc0 d7e43dc0 d7e43dc4 0000001c 00000004
      f496d1e0 f8d23ffc d7e43dd4 f8ffac7e f8d23ffe 00000000 f8d23ffe f2b7af68
      f496d1e0 f8d23ffc d7e43e2c f8ffadc5 00000000 0001f000 00000000 c03b10a7
Call Trace:
[<c0103db4>] ? restore_nocheck_notrace+0x0/0xe
[<f8ffac7e>] ? is_a_node+0x43/0x92 [ubifs]
[<f8ffadc5>] ? dbg_check_ltab+0xf8/0x5c9 [ubifs]
[<c03b10a7>] ? mutex_lock_nested+0x1b2/0x2a0
[<f8ffc86e>] ? ubifs_lpt_start_commit+0x49/0xecb [ubifs]
[<c03b0ef3>] ? mutex_unlock+0xd/0xf
[<f8fef017>] ? ubifs_tnc_start_commit+0x1cf/0xef8 [ubifs]
[<f8fe65d8>] ? do_commit+0x18f/0x52d [ubifs]
[<f8fe69f6>] ? ubifs_run_commit+0x80/0xca [ubifs]
[<f8fd8d35>] ? ubifs_sync_fs+0xdb/0xf6 [ubifs]
[<c0181a07>] ? sync_filesystems+0xc6/0x10c
[<c019f279>] ? do_sync+0x3b/0x6a
[<c019f2ba>] ? sys_sync+0x12/0x18
[<c0103ced>] ? sysenter_do_call+0x12/0x35
=======================
Code: 4d ec 89 01 8b 45 e8 89 10 89 d8 89 f1 d3 e8 85 c0 74 07 29 d6 83 fe
20 75 2a 89 d8 83 c4 1c 5b 5e 5f 5d c3 0f b6 57 01 c1 e2 08 <0f> b6 47 02
c1 e0 10 09 c2 0f b6 07 09 c2 0f b
EIP: [<f8ff0657>] ubifs_unpack_bits+0xcd/0x231 [ubifs] SS:ESP 0068:d7e43d8c
---[ end trace 1bbb4c407a6dd816 ]---
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

'is_a_node()' function was reading from a buffer before
checking the buffer length, resulting in an OOPS as
follows:

BUG: unable to handle kernel paging request at f8f74002
IP: [<f8f9783f>] :ubifs:ubifs_unpack_bits+0xca/0x233
*pde = 19e95067 *pte = 00000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: ubifs ubi mtdchar bio2mtd mtd brd video output
[last unloaded: mtd]

Pid: 6414, comm: integck Not tainted (2.6.27-rc6ubifs34 #23)
EIP: 0060:[<f8f9783f>] EFLAGS: 00010246 CPU: 0
EIP is at ubifs_unpack_bits+0xca/0x233 [ubifs]
EAX: 00000000 EBX: f6090630 ECX: d9badcfc EDX: 00000000
ESI: 00000004 EDI: f8f74002 EBP: d9badcec ESP: d9badcc0
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process integck (pid: 6414, ti=d9bac000 task=f727dae0 task.ti=d9bac000)
Stack: 00000006 f7306240 00000002 00000000 d9badcfc d9badd00 0000001c 00000000
       f6090630 f6090630 f8f74000 d9badd10 f8fa1cc9 00000000 f8f74002 00000000
       f8f74002 f60fe128 f6090630 f8f74000 d9badd68 f8fa1e46 00000000 0001e000
Call Trace:
 [<f8fa1cc9>] ? is_a_node+0x30/0x90 [ubifs]
 [<f8fa1e46>] ? dbg_check_ltab+0x11d/0x5bd [ubifs]
 [<f8fa388f>] ? ubifs_lpt_start_commit+0x42/0xed3 [ubifs]
 [<c038e76a>] ? mutex_unlock+0x8/0xa
 [<f8f9625d>] ? ubifs_tnc_start_commit+0x1c8/0xedb [ubifs]
 [<f8f8d90b>] ? do_commit+0x187/0x523 [ubifs]
 [<c038e76a>] ? mutex_unlock+0x8/0xa
 [<f8f7ca17>] ? bud_wbuf_callback+0x22/0x28 [ubifs]
 [<f8f8dd1d>] ? ubifs_run_commit+0x76/0xc0 [ubifs]
 [<f8f8032c>] ? ubifs_sync_fs+0xd2/0xe6 [ubifs]
 [<c01a2e97>] ? vfs_quota_sync+0x0/0x17e
 [<c01a5ba6>] ? quota_sync_sb+0x26/0xbb
 [<c01a2e97>] ? vfs_quota_sync+0x0/0x17e
 [<c01a5c5d>] ? sync_dquots+0x22/0x12c
 [<c0173d1b>] ? __fsync_super+0x19/0x68
 [<c0173d75>] ? fsync_super+0xb/0x19
 [<c0174065>] ? generic_shutdown_super+0x22/0xe7
 [<c01a31fc>] ? vfs_quota_off+0x0/0x5fd
 [<f8f7cf4d>] ? ubifs_kill_sb+0x31/0x35 [ubifs]
 [<c01741f9>] ? deactivate_super+0x5e/0x71
 [<c0187610>] ? mntput_no_expire+0x82/0xe4
 [<c0187905>] ? sys_umount+0x4c/0x2f6
 [<c0187bc8>] ? sys_oldumount+0x19/0x1b
 [<c0103b71>] ? sysenter_do_call+0x12/0x25
 =======================
Code: c1 f8 03 8d 04 07 8b 4d e8 89 01 8b 45 e4 89 10 89 d8 89 f1 d3 e8 85 c0
      74 07 29 d6 83 fe 20 75 2a 89 d8 83 c4 20 5b 5e 5f 5d
EIP: [<f8f9783f>] ubifs_unpack_bits+0xca/0x233 [ubifs] SS:ESP 0068:d9badcc0
---[ end trace 1f02572436518c13 ]---
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Also add debugging checks for LPT size and separate
out c->check_lpt_free from unrelated bitfields.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Bulk-read skips uptodate pages but this was putting its
array index out and causing it to treat subsequent pages
as holes.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Make garbage collection try to keep data nodes from the same
inode together and in ascending order.  This improves
performance when reading those nodes especially when bulk-read
is used.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

sync_fs can be called even if the file system is mounted
read-only.  Ensure the commit is not run in that case.
Reported-by: NZoltan Sogor <weth@inf.u-szeged.hu>
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Commit the journal when the FS is sync'ed. This will make
statfs provide better free space report. And we anyway
advice our users to sync the FS if they want better statfs
report.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

'dbg_dump_inode()' is quite outdated and does not print all
the fileds.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Znode may refer both data nodes and indexing nodes
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We cannot store bit-fields together if the processes which
change them may race, unless we serialize them.

Thus, move the nospc and nospc_rp bit-fields eway from
the mount option/constant bit-fields, to avoid races.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

The comparison was working, but more by accident than design.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

The "bulk_read" and "no_chk_data_crc" have only 2 values -
0 and 1. We already have bit-fields in corresponding data
structers, so make "bulk_read" and "no_chk_data_crc"
bit-fields as well.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When UBIFS switches to R/O mode because of an error,
it is reasonable to enable data CRC checking.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When inserting into a full znode it is split into two
znodes.  Because data node keys are usually consecutive,
it is better to try to keep them together.  This patch
does a better job of that.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

UBIFS read performance can be improved by skipping the CRC
check when data nodes are read.  This option can be used if
the underlying media is considered to be highly reliable.
Note that CRCs are always checked for metadata.

Read speed on Arm platform with OneNAND goes from 19 MiB/s
to 27 MiB/s with data CRC checking disabled.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Some flash media are capable of reading sequentially at faster rates.
UBIFS bulk-read facility is designed to take advantage of that, by
reading in one go consecutive data nodes that are also located
consecutively in the same LEB.

Read speed on Arm platform with OneNAND goes from 17 MiB/s to
19 MiB/s.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

In case of error, the function kthread_create returns an ERR pointer,
but never returns a NULL pointer. So a NULL test that comes before an
IS_ERR test should be deleted.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@match_bad_null_test@
expression x, E;
statement S1,S2;
@@
x = kthread_create(...)
... when != x = E
* if (x == NULL)
S1 else S2
// </smpl>
Signed-off-by: NJulien Brunel <brunel@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

'ubifs_get_lprops()' and 'ubifs_release_lprops()' basically wrap
mutex lock and unlock. We have them because we want lprops subsystem
be separate and as independent as possible. And we planned better
locking rules for lprops.

Anyway, because they are short, it is better to inline them.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>