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Commit Graph

38 Commits

Author SHA1 Message Date
Marcin Slusarz
50e8a2890e ext3: replace all adds to little endians variables with le*_add_cpu
replace all:
	little_endian_variable = cpu_to_leX(leX_to_cpu(little_endian_variable) +
				expression_in_cpu_byteorder);
with:
	leX_add_cpu(&little_endian_variable, expression_in_cpu_byteorder);
sparse didn't generate any new warning with this patch

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:32 -08:00
Akinobu Mita
859cb93679 ext[234]: cleanup ext[234]_bg_num_gdb()
Use ext[234]_bg_has_super() to remove duplicate code.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:21 -08:00
Akinobu Mita
144704e522 ext[234]: fix comment for nonexistent variable
The comment in ext[234]_new_blocks() describes about "i".  But there is no
local variable called "i" in that scope.  I guess it has been renamed to
group_no.

Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:21 -08:00
Aneesh Kumar K.V
feda58d37a ext3: return after ext3_error in case of failures
This fixes some instances where we were continuing after calling
ext3_error.  ext3_error calls panic only if errors=panic mount option is
set.  So we need to make sure we return correctly after ext3_error call

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:20 -08:00
Aneesh Kumar K.V
f762e9054f ext3: add block bitmap validation
When a new block bitmap is read from disk in read_block_bitmap() there are a
few bits that should ALWAYS be set.  In particular, the blocks given
corresponding to block bitmap, inode bitmap and inode tables.  Validate the
block bitmap against these blocks.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:20 -08:00
Linus Torvalds
0b832a4b93 Revert "ext2/ext3/ext4: add block bitmap validation"
This reverts commit 7c9e69faa2, fixing up
conflicts in fs/ext4/balloc.c manually.

The cost of doing the bitmap validation on each lookup - even when the
bitmap is cached - is absolutely prohibitive.  We could, and probably
should, do it only when adding the bitmap to the buffer cache.  However,
right now we are better off just reverting it.

Peter Zijlstra measured the cost of this extra validation as a 85%
decrease in cached iozone, and while I had a patch that took it down to
just 17% by not being _quite_ so stupid in the validation, it was still
a big slowdown that could have been avoided by just doing it right.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-13 08:09:11 -08:00
Aneesh Kumar K.V
7c9e69faa2 ext2/ext3/ext4: add block bitmap validation
When a new block bitmap is read from disk in read_block_bitmap() there are
a few bits that should ALWAYS be set.  In particular, the blocks given by
ext4_blk_bitmap, ext4_inode_bitmap and ext4_inode_table.  Validate the
block bitmap against these blocks.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Acked-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:52 -07:00
Peter Zijlstra
3cb4f9fa0c lib: percpu_counter_sub
Hugh spotted that some code does:
  percpu_counter_add(&counter, -unsignedlong)

which, when the amount argument is of type s32, sort-of works thanks to
two's-complement. However when we'd change the type to s64 this breaks on 32bit
machines, because the promotion rules zero extend the unsigned number.

Provide percpu_counter_sub() to hide the s64 cast. That is:
  percpu_counter_sub(&counter, foo)
is equal to:
  percpu_counter_add(&counter, -(s64)foo);

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:44 -07:00
Peter Zijlstra
aa0dff2d09 lib: percpu_counter_add
s/percpu_counter_mod/percpu_counter_add/

Because its a better name, _mod implies modulo.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:44 -07:00
Aneesh Kumar K.V
e627432c29 [PATCH] ext[234]: update documentation
Signed-off-by: "Aneesh Kumar K.V" <aneesh.kumar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20 17:10:14 -08:00
Hugh Dickins
7d1c520bb5 [PATCH] ext3 balloc: fix _with_rsv freeze
Port fix to the off-by-one in find_next_usable_block's memscan from ext2 to
ext3; but it didn't cause a serious problem for ext3 because the additional
ext3_test_allocatable check rescued it from the error.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:48 -08:00
Hugh Dickins
2823b5535e [PATCH] ext3 balloc: use io_error label
ext3_new_blocks has a nice io_error label for setting -EIO, so goto that in
the one place that doesn't already use it.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:48 -08:00
Hugh Dickins
c56d2561f7 [PATCH] ext3 balloc: say rb_entry not list_entry
The reservations tree is an rb_tree not a list, so it's less confusing to use
rb_entry() than list_entry() - though they're both just container_of().

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:48 -08:00
Hugh Dickins
ff50dc562b [PATCH] ext3 balloc: fix off-by-one against rsv_end
rsv_end is the last block within the reservation, so alloc_new_reservation
should accept start_block == rsv_end as success.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:48 -08:00
Hugh Dickins
1650242324 [PATCH] ext3 balloc: fix off-by-one against grp_goal
grp_goal 0 is a genuine goal (unlike -1), so ext3_try_to_allocate_with_rsv
should treat it as such.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:48 -08:00
Hugh Dickins
ef5036782e [PATCH] ext3 balloc: reset windowsz when full
ext3_new_blocks should reset the reservation window size to 0 when squeezing
the last blocks out of an almost full filesystem, so the retry doesn't skip
any groups with less than half that free, reporting ENOSPC too soon.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:48 -08:00
Mingming Cao
2bd94bd79e [PATCH] ext3: fix reservation extension
Hugh Dickins wrote:
> Not found anything relevant, but I keep noticing these lines
> in ext2_try_to_allocate_with_rsv(), ext3 and ext4 similar:
>
> 		} else if (grp_goal > 0 &&
> 				(my_rsv->rsv_end - grp_goal + 1) < *count)
> 			try_to_extend_reservation(my_rsv, sb,
> 					*count-my_rsv->rsv_end + grp_goal - 1);
>
> They're wrong, a no-op in most groups, aren't they?  rsv_end is an
> absolute block number, whereas grp_goal is group-relative, so the
> calculation ought to bring in group_first_block?  Or I'm confused.
>

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Cc: "linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:39 -08:00
Eric Sandeen
32c2d2bc4b [PATCH] more ext3 16T overflow fixes
Some of the changes in balloc.c are just cosmetic, as Andreas pointed out -
if they overflow they'll then underflow and things are fine.

5th hunk actually fixes an overflow problem.

Also check for potential overflows in inode & block counts when resizing.

Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:10 -07:00
Dave Kleikamp
e9ad5620bf [PATCH] ext3: More whitespace cleanups
More white space cleanups in preparation of cloning ext4 from ext3.
Removing spaces that precede a tab.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:10 -07:00
Mingming Cao
36faadc144 [PATCH] ext3: more comments about block allocation/reservation code
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:09 -07:00
Mingming Cao
321fb9e818 [PATCH] ext3: turn on reservation dump on block allocation errors
In the past there were a few kernel panics related to block reservation
tree operations failure (insert/remove etc).  It would be very useful to
get the block allocation reservation map info when such error happens.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:09 -07:00
Mingming Cao
ae6ddcc5f2 [PATCH] ext3 and jbd cleanup: remove whitespace
Remove whitespace from ext3 and jbd, before we clone ext4.

Signed-off-by: Mingming Cao<cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:09 -07:00
Mingming Cao
08fb306fe6 [PATCH] ext3 filesystem bogus ENOSPC with reservation fix
To handle the earlier bogus ENOSPC error caused by filesystem full of block
reservation, current code falls back to non block reservation, starts to
allocate block(s) from the goal allocation block group as if there is no
block reservation.

Current code needs to re-load the corresponding block group descriptor for
the initial goal block group in this case.  The patch fixes this.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:30 -07:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Mingming Cao
43d23f9039 [PATCH] ext3_fsblk_t: the rest of in-kernel filesystem blocks conversion
Convert the ext3 in-kernel filesystem blocks to ext3_fsblk_t.  Convert the
rest of all unsigned long type in-kernel filesystem blocks to ext3_fsblk_t,
and replace the printk format string respondingly.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:10 -07:00
Mingming Cao
1c2bf374a4 [PATCH] ext3_fsblk_t: filesystem, group blocks and bug fixes
Some of the in-kernel ext3 block variable type are treated as signed 4 bytes
int type, thus limited ext3 filesystem to 8TB (4kblock size based).  While
trying to fix them, it seems quite confusing in the ext3 code where some
blocks are filesystem-wide blocks, some are group relative offsets that need
to be signed value (as -1 has special meaning).  So it seem saner to define
two types of physical blocks: one is filesystem wide blocks, another is
group-relative blocks.  The following patches clarify these two types of
blocks in the ext3 code, and fix the type bugs which limit current 32 bit ext3
filesystem limit to 8TB.

With this series of patches and the percpu counter data type changes in the mm
tree, we are able to extend exts filesystem limit to 16TB.

This work is also a pre-request for the recent >32 bit ext3 work, and makes
the kernel to able to address 48 bit ext3 block a lot easier: Simply redefine
ext3_fsblk_t from unsigned long to sector_t and redefine the format string for
ext3 filesystem block corresponding.

Two RFC with a series patches have been posted to ext2-devel list and have
been reviewed and discussed:
http://marc.theaimsgroup.com/?l=ext2-devel&m=114722190816690&w=2

http://marc.theaimsgroup.com/?l=ext2-devel&m=114784919525942&w=2

Patches are tested on both 32 bit machine and 64 bit machine, <8TB ext3 and
>8TB ext3 filesystem(with the latest to be released e2fsprogs-1.39).  Tests
includes overnight fsx, tiobench, dbench and fsstress.

This patch:

Defines ext3_fsblk_t and ext3_grpblk_t, and the printk format string for
filesystem wide blocks.

This patch classifies all block group relative blocks, and ext3_fsblk_t blocks
occurs in the same function where used to be confusing before.  Also include
kernel bug fixes for filesystem wide in-kernel block variables.  There are
some fileystem wide blocks are treated as int/unsigned int type in the kernel
currently, especially in ext3 block allocation and reservation code.  This
patch fixed those bugs by converting those variables to ext3_fsblk_t(unsigned
long) type.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:10 -07:00
Mingming Cao
d48589bfad [PATCH] ext3_get_blocks: Adjust reservation window size for mblocks
Optimize the block reservation and the multiple block allocation: with the
knowledge of the total number of blocks ahead, set or adjust the reservation
window size properly (based on the number of blocks needed) before block
allocation happens: if there isn't any reservation yet, make sure the
reservation window equals to or greater than the number of blocks needed,
before create an reservation window; if a reservation window is already
exists, try to extends the window size to match the number of blocks to
allocate.  This could increase the possibility of completing multiple blocks
allocation in a single request, as blocks are only allocated in the range of
the inode's reservation window.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:01 -08:00
Mingming Cao
faa569763a [PATCH] ext3_get_blocks: Adjust accounting info in ext3_new_blocks()
Update accounting information (quota, boundary checks, free blocks number etc)
in ext3_new_blocks().

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:01 -08:00
Mingming Cao
b54e41ec17 [PATCH] ext3_get_blocks: support multiple blocks allocation in ext3_new_block()
Change ext3_try_to_allocate() (called via ext3_new_blocks()) to try to
allocate the requested number of blocks on a best effort basis: After
allocated the first block, it will always attempt to allocate the next few(up
to the requested size and not beyond the reservation window) adjacent blocks
at the same time.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:01 -08:00
Glauber de Oliveira Costa
b5a7c4f583 [PATCH] ext3: Properly report backup block present in a group
In filesystems with the meta block group flag on, ext3_bg_num_gdb() fails
to report the correct number of blocks used to store the group descriptor
backups in a given group.  It happens because meta_bg follows a different
logic from the original ext3 backup placement in groups multiples of 3, 5
and 7.

Signed-off-by: Glauber de Oliveira Costa <glommer@br.ibm.com>
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Alex Tomas <alex@clusterfs.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:30 -08:00
Randy Dunlap
16f7e0fe2e [PATCH] capable/capability.h (fs/)
fs: Use <linux/capability.h> where capable() is used.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:13 -08:00
Adrian Bunk
3af13763d6 [PATCH] fs/ext3/: small cleanups
This patch contains the following cleanups:
- there's no need for ext3_count_free() #ifndef EXT3FS_DEBUG
- having prototypes for ext3_count_free() in two different headers is
  nonsense

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:56 -08:00
Adrian Bunk
2860b733f1 [PATCH] remove CONFIG_EXT{2,3}_CHECK
The CONFIG_EXT{2,3}_CHECK options where were never available, and all they
did was to implement a subset of e2fsck in the kernel.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:58 -08:00
Ben Dooks
381be25458 [PATCH] ext3: sparse fixes
Fix warnings from sparse due to un-declared functions that should either
have a header file or have been declared static

 fs/ext2/bitmap.c:14:15: warning: symbol 'ext2_count_free' was not declared. Should it be static?
 fs/ext2/namei.c:92:15: warning: symbol 'ext2_get_parent' was not declared. Should it be static?
 fs/ext3/bitmap.c:15:15: warning: symbol 'ext3_count_free' was not declared. Should it be static?
 fs/ext3/namei.c:1013:15: warning: symbol 'ext3_get_parent' was not declared. Should it be static?
 fs/ext3/xattr.c:214:1: warning: symbol 'ext3_xattr_block_get' was not declared. Should it be static?
 fs/ext3/xattr.c:358:1: warning: symbol 'ext3_xattr_block_list' was not declared. Should it be static?
 fs/ext3/xattr.c:630:1: warning: symbol 'ext3_xattr_block_find' was not declared. Should it be static?
 fs/ext3/xattr.c:863:1: warning: symbol 'ext3_xattr_ibody_find' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:25 -08:00
Glauber de Oliveira Costa
5b11687924 [PATCH] Locking problems while EXT3FS_DEBUG on
I noticed some problems while running ext3 with the debug flag set on.
More precisely, I was unable to umount the filesystem.  Some investigation
took me to the patch that follows.

At a first glance , the lock/unlock I've taken out seems really not
necessary, as the main code (outside debug) does not lock the super.  The
only additional danger operations that debug code introduces seems to be
related to bitmap, but bitmap operations tends to be all atomic anyway.

I also took the opportunity to fix 2 spelling errors.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:23 -08:00
Glauber de Oliveira Costa
8bdac5d1ed [PATCH] ext3: EXT3_DEBUG build fixes
Fix some warnings and a build error when EXT3_DEBUG is enabled.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22 22:17:37 -07:00
Mingming Cao
21fe3471c3 [PATCH] ext3: reduce allocate-with-reservation lock latencies
Currently in ext3 block reservation code, the global filesystem reservation
tree lock (rsv_block) is hold during the process of searching for a space
to make a new reservation window, including while scaning the block bitmap
to verify if the avalible window has a free block.  Holding the lock during
bitmap scan is unnecessary and could possibly cause scalability issue and
latency issues.

This patch tries to address this by dropping the lock before scan the
bitmap.  Before that we need to reserve the open window in case someone
else is targetting at the same window.  Question was should we reserve the
whole free reservable space or just the window size we need.  Reserve the
whole free reservable space will possibly force other threads which
intended to do block allocation nearby move to another block group(cause
bad layout).  In this patch, we just reserve the desired size before drop
the lock and scan the block bitmap.  This patch fixed a ext3 reservation
latency issue seen on a cvs check out test.  Patch is tested with many fsx,
tiobench, dbench and untar a kernel test.

Signed-Off-By: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28 21:20:35 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00