13172 Commits

Author SHA1 Message Date
Duane Griffin
f33219b7a9 ufs: don't truncate longer ufs2 fast symlinks
ufs2 fast symlinks can be twice as long as ufs ones, however the code
was using the ufs size in various places. Fix that so ufs2 symlinks over
60 characters aren't truncated.

Note that we copy the entire area instead of using the maxsymlinklen field
from the superblock. This way we will be more robust against corruption (of
the superblock).

While we are at it, use memcpy instead of open-coding it with for loops.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:58 -04:00
Duane Griffin
9e6766cc8c ufs: validate maximum fast symlink size from superblock
The maximum fast symlink size is set in the superblock of certain types
of UFS filesystem. Before using it we need to check that it isn't longer
than the available space we have in the inode.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:57 -04:00
Christoph Hellwig
c8fe8f30c7 cleanup may_open
Add a switch for the various i_mode fmt cases, and remove the comment
about writeability of devices nodes - that part is handled in
inode_permission and comment on (briefly) there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:57 -04:00
Christoph Hellwig
b6520c8193 cleanup d_add_ci
Make sure that comments describe what's going on and not how, and always
use __d_instantiate instead of two separate branches, one with
d_instantiate and one with __d_instantiate.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:57 -04:00
Christoph Hellwig
2b1c6bd77d generic compat_sys_ustat
Due to a different size of ino_t ustat needs a compat handler, but
currently only x86 and mips provide one.  Add a generic compat_sys_ustat
and switch all architectures over to it.  Instead of doing various
user copy hacks compat_sys_ustat just reimplements sys_ustat as
it's trivial.  This was suggested by Arnd Bergmann.

Found by Eric Sandeen when running xfstests/017 on ppc64, which causes
stack smashing warnings on RHEL/Fedora due to the too large amount of
data writen by the syscall.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:57 -04:00
Christoph Hellwig
ec1ab0abde affs: fix missing unlocks in affs_remove_link
In two error cases affs_remove_link doesn't call affs_unlock_dir to
release the i_hash_lock semaphore.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:56 -04:00
Linus Torvalds
8e9d208972 Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6
* 'bkl-removal' of git://git.lwn.net/linux-2.6:
  Rationalize fasync return values
  Move FASYNC bit handling to f_op->fasync()
  Use f_lock to protect f_flags
  Rename struct file->f_ep_lock
2009-03-26 16:14:02 -07:00
Linus Torvalds
21cdbc1378 Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (81 commits)
  [S390] remove duplicated #includes
  [S390] cpumask: use mm_cpumask() wrapper
  [S390] cpumask: Use accessors code.
  [S390] cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.
  [S390] cpumask: remove cpu_coregroup_map
  [S390] fix clock comparator save area usage
  [S390] Add hwcap flag for the etf3 enhancement facility
  [S390] Ensure that ipl panic notifier is called late.
  [S390] fix dfp elf hwcap/facility bit detection
  [S390] smp: perform initial cpu reset before starting a cpu
  [S390] smp: fix memory leak on __cpu_up
  [S390] ipl: Improve checking logic and remove switch defaults.
  [S390] s390dbf: Remove needless check for NULL pointer.
  [S390] s390dbf: Remove redundant initilizations.
  [S390] use kzfree()
  [S390] BUG to BUG_ON changes
  [S390] zfcpdump: Prevent zcore from beeing built as a kernel module.
  [S390] Use csum_partial in checksum.h
  [S390] cleanup lowcore.h
  [S390] eliminate ipl_device from lowcore
  ...
2009-03-26 16:04:22 -07:00
Linus Torvalds
86d9c07017 Merge branch 'for-2.6.30' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.30' of git://git.kernel.dk/linux-2.6-block:
  Get rid of pdflush_operation() in emergency sync and remount
  btrfs: get rid of current_is_pdflush() in btrfs_btree_balance_dirty
  Move the default_backing_dev_info out of readahead.c and into backing-dev.c
  block: Repeated lines in switching-sched.txt
  bsg: Remove bogus check against request_queue->max_sectors
  block: WARN in __blk_put_request() for potential bio leak
  loop: fix circular locking in loop_clr_fd()
  loop: support barrier writes
  bsg: add support for tail queuing
  cpqarray: enable bus mastering
  block: genhd.h cleanup patch
  block: add private bio_set for bio integrity allocations
  block: genhd.h comment needs updating
  block: get rid of unused blkdev_free_rq() define
  block: remove various blk_queue_*() setting functions in blk_init_queue_node()
  cciss: add BUILD_BUG_ON() for catching bad CommandList_struct alignment
  block: don't create bio_vec slabs of less than the inline number
  block: cleanup bio_alloc_bioset()
2009-03-26 16:03:04 -07:00
Linus Torvalds
13220a94d3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1750 commits)
  ixgbe: Allow Priority Flow Control settings to survive a device reset
  net: core: remove unneeded include in net/core/utils.c.
  e1000e: update version number
  e1000e: fix close interrupt race
  e1000e: fix loss of multicast packets
  e1000e: commonize tx cleanup routine to match e1000 & igb
  netfilter: fix nf_logger name in ebt_ulog.
  netfilter: fix warning in ebt_ulog init function.
  netfilter: fix warning about invalid const usage
  e1000: fix close race with interrupt
  e1000: cleanup clean_tx_irq routine so that it completely cleans ring
  e1000: fix tx hang detect logic and address dma mapping issues
  bridge: bad error handling when adding invalid ether address
  bonding: select current active slave when enslaving device for mode tlb and alb
  gianfar: reallocate skb when headroom is not enough for fcb
  Bump release date to 25Mar2009 and version to 0.22
  r6040: Fix second PHY address
  qeth: fix wait_event_timeout handling
  qeth: check for completion of a running recovery
  qeth: unregister MAC addresses during recovery.
  ...

Manually fixed up conflicts in:
	drivers/infiniband/hw/cxgb3/cxio_hal.h
	drivers/infiniband/hw/nes/nes_nic.c
2009-03-26 15:54:36 -07:00
Linus Torvalds
39f15003c7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [CIFS] Fix memory overwrite when saving nativeFileSystem field during mount
  [CIFS]  Rename compose_mount_options to cifs_compose_mount_options.
  [CIFS] work around bug in Samba server handling for posix open
  [CIFS] Use posix open on file open when server supports it
  cifs: fix buffer format byte on NT Rename/hardlink
  [CIFS] Add definitions for remoteably fsctl calls
  [CIFS] add extra null attr check
  [CIFS] fix build error
  [CIFS] reopen file via newer posix open protocol operation if available
  [CIFS] Add new nostrictsync cifs mount option to avoid slow SMB flush
  [CIFS] DFS no longer experimental
  [CIFS] Send SMB flush in cifs_fsync
2009-03-26 15:46:37 -07:00
Jan Kara
9e80d40773 ext3: Avoid starting a transaction in writepage when not necessary
We don't have to start a transaction in writepage() when all the blocks
are a properly allocated. Even in ordered mode either the data has been
written via write() and they are thus already added to transaction's list
or the data was written via mmap and then it's random in which transaction
they get written anyway.

This should help VM to pageout dirty memory without blocking on transaction
commits.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26 15:44:59 -07:00
David S. Miller
08abe18af1 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	drivers/net/wimax/i2400m/usb-notif.c
2009-03-26 15:23:24 -07:00
Linus Torvalds
0c93ea4064 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (61 commits)
  Dynamic debug: fix pr_fmt() build error
  Dynamic debug: allow simple quoting of words
  dynamic debug: update docs
  dynamic debug: combine dprintk and dynamic printk
  sysfs: fix some bin_vm_ops errors
  kobject: don't block for each kobject_uevent
  sysfs: only allow one scheduled removal callback per kobj
  Driver core: Fix device_move() vs. dpm list ordering, v2
  Driver core: some cleanup on drivers/base/sys.c
  Driver core: implement uevent suppress in kobject
  vcs: hook sysfs devices into object lifetime instead of "binding"
  driver core: fix passing platform_data
  driver core: move platform_data into platform_device
  sysfs: don't block indefinitely for unmapped files.
  driver core: move knode_bus into private structure
  driver core: move knode_driver into private structure
  driver core: move klist_children into private structure
  driver core: create a private portion of struct device
  driver core: remove polling for driver_probe_done(v5)
  sysfs: reference sysfs_dirent from sysfs inodes
  ...

Fixed conflicts in drivers/sh/maple/maple.c manually
2009-03-26 11:17:04 -07:00
Linus Torvalds
8ff64b539b Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw:
  GFS2: Fix freeze issue
  Fix a minor bug in the previous patch
  GFS2: Clean up of glops.c
  GFS2: Fix locking bug in failed shared to exclusive conversion
  GFS2: Pagecache usage optimization on GFS2
  GFS2: fix sparse warning: Should it be static?
  GFS2: fix sparse warnings: constant is so big it is ...
  GFS2: Support quota/noquota mount arguments
  GFS2: Fix alignment issue and tidy gfs2_bitfit
  GFS2: Add a "demote a glock" interface to sysfs
  GFS2: Expose UUID via sysfs/uevent
  GFS2: Support generation of discard requests
  GFS2: Fix deadlock on journal flush
  GFS2: Fix error path ref counting for root inode
  GFS2: Remove unused field from glock
  GFS2: Merge lock_dlm module into GFS2
  GFS2: Remove "double" locking in quota
  GFS2: change gfs2_quota_scan into a shrinker
  GFS2: Bring back lvb-related stuff to lock_nolock to support quotas
  GFS2: Fix remount argument parsing
2009-03-26 11:08:47 -07:00
Linus Torvalds
8d80ce80e1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (71 commits)
  SELinux: inode_doinit_with_dentry drop no dentry printk
  SELinux: new permission between tty audit and audit socket
  SELinux: open perm for sock files
  smack: fixes for unlabeled host support
  keys: make procfiles per-user-namespace
  keys: skip keys from another user namespace
  keys: consider user namespace in key_permission
  keys: distinguish per-uid keys in different namespaces
  integrity: ima iint radix_tree_lookup locking fix
  TOMOYO: Do not call tomoyo_realpath_init unless registered.
  integrity: ima scatterlist bug fix
  smack: fix lots of kernel-doc notation
  TOMOYO: Don't create securityfs entries unless registered.
  TOMOYO: Fix exception policy read failure.
  SELinux: convert the avc cache hash list to an hlist
  SELinux: code readability with avc_cache
  SELinux: remove unused av.decided field
  SELinux: more careful use of avd in avc_has_perm_noaudit
  SELinux: remove the unused ae.used
  SELinux: check seqno when updating an avc_node
  ...
2009-03-26 11:03:39 -07:00
Matthew Garrett
0a1c01c947 Make relatime default
Change the default behaviour of the kernel to use relatime for all
filesystems. This can be overridden with the "strictatime" mount
option.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26 11:01:10 -07:00
Matthew Garrett
d0adde574b Add a strictatime mount option
Add support for explicitly requesting full atime updates. This makes it
possible for kernels to default to relatime but still allow userspace to
override it.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26 10:56:35 -07:00
Matthew Garrett
11ff6f05f1 Allow relatime to update atime once a day
Allow atime to be updated once per day even with relatime. This lets
utilities like tmpreaper (which delete files based on last access time)
continue working, making relatime a plausible default for distributions.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Valerie Aurora Henson <vaurora@redhat.com>
Acked-by: Alan Cox <alan@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26 10:48:13 -07:00
Stefan Weinhuber
b44b0ab3ba [S390] dasd: add large volume support
The dasd device driver will now support ECKD devices with more then
65520 cylinders.
In the traditional ECKD adressing scheme each track is addressed
by a 16-bit cylinder and 16-bit head number. The new addressing
scheme makes use of the fact that the actual number of heads is
never larger then 15, so 12 bits of the head number can be redefined
to be part of the cylinder address.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26 15:24:05 +01:00
Jens Axboe
a2a9537ac0 Get rid of pdflush_operation() in emergency sync and remount
Opencode a cheasy approach with kevent. The idea here is that we'll
add some generic delayed work infrastructure, which probably wont be
based on pdflush (or maybe it will, in which case we can just add it
back).

This is in preparation for getting rid of pdflush completely.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-26 11:01:36 +01:00
Jens Axboe
6933c02e9c btrfs: get rid of current_is_pdflush() in btrfs_btree_balance_dirty
Chris says it's safe to kill.

Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-26 11:01:35 +01:00
Theodore Ts'o
563bdd61fe ext4: Check for an valid i_mode when reading the inode from disk
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-03-26 00:06:19 -04:00
Theodore Ts'o
7058548cd5 ext4: Use WRITE_SYNC for commits which are caused by fsync()
If a commit is triggered by fsync(), set a flag indicating the journal
blocks associated with the transaction should be flushed out using
WRITE_SYNC.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-03-25 23:35:46 -04:00
Manish Katiyar
c16831b4cc ext2: Zero our b_size in ext2_quota_read()
ext2_quota_read() doesn't initialize tmp_bh.b_size before calling
ext2_get_block() where we access it. Since it is a local variable it
might contain some garbage. Make sure it is filled with reasonable
value before passing.

Signed-off-by: Manish Katiyar <mkatiyar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:38 +01:00
Matt LaPlante
620372a9ff trivial: fix typos/grammar errors in fs/Kconfig
Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:38 +01:00
Jan Kara
268157ba67 quota: Coding style fixes
Wrap long lines, remove assignments from conditions, rewrite two
overcomplicated for loops.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:38 +01:00
Jan Kara
7a2435d874 quota: Remove superfluous inlines
Remove inlines of large functions to decrease code size (saved 1543
bytes).

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:37 +01:00
Jan Kara
90c0af05a5 nfsd: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

CC: bfields@fieldses.org
CC: neilb@suse.de
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:37 +01:00
Jan Kara
c94d2a22f2 jfs: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
2009-03-26 02:18:37 +01:00
Jan Kara
bacfb7c2e5 udf: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:36 +01:00
Jan Kara
5f5fa796c6 ufs: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
CC: Evgeniy Dushistov <dushistov@mail.ru>
2009-03-26 02:18:36 +01:00
Jan Kara
77db4f25bc reiserfs: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
CC: reiserfs-devel@vger.kernel.org
2009-03-26 02:18:36 +01:00
Jan Kara
a269eb1829 ext4: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mingming Cao <cmm@us.ibm.com>
CC: linux-ext4@vger.kernel.org
2009-03-26 02:18:36 +01:00
Jan Kara
81a0522739 ext3: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
CC: linux-ext4@vger.kernel.org
2009-03-26 02:18:36 +01:00
Jan Kara
6f90bee506 ext2: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
CC: linux-ext4@vger.kernel.org
2009-03-26 02:18:36 +01:00
Jan Kara
314649558d ramfs: Remove quota call
Ramfs has no bussiness in quotas.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:35 +01:00
Jan Kara
9e3509e273 vfs: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
2009-03-26 02:18:35 +01:00
Jan Kara
d26ac1a812 quota: Remove dqbuf_t and other cleanups
Remove bogus typedef which is just a definition of char *.
Remove unnecessary type casts.
Substitute freedqbuf() with kfree.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:35 +01:00
Jan Kara
dd6f3c6d5a quota: Remove NODQUOT macro
Remove this macro which is just a definition of NULL. Fix a few coding style
issues along the way.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:35 +01:00
Jan Kara
c516610cfe quota: Make global quota locks cacheline aligned
Andrew Morton has suggested that three global quota locks can end up in the
same cacheline which can result in bad cacheline ping-pong on SMP machines.
Make locks cacheline aligned so that we avoid this problem (thanks goes to
Andrew for the idea).

Signed-off-by: Jan Kara <jack@suse.cz>
CC: Andrew Morton <akpm@linux-foundation.org>
2009-03-26 02:18:35 +01:00
Jan Kara
884d179dff quota: Move quota files into separate directory
Quota subsystem has more and more files. It's time to create a dir for it.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:35 +01:00
Mingming Cao
60e58e0f30 ext4: quota reservation for delayed allocation
Uses quota reservation/claim/release to handle quota properly for delayed
allocation in the three steps: 1) quotas are reserved when data being copied
to cache when block allocation is defered 2) when new blocks are allocated.
reserved quotas are converted to the real allocated quota, 2) over-booked
quotas for metadata blocks are released back.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:34 +01:00
Jan Kara
643d00ccc3 reiserfs: Remove unnecessary quota functions
reiserfs_dquot_initialize() and reiserfs_dquot_drop() is no longer
needed because of modified quota locking.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:34 +01:00
Jan Kara
edf7245362 ext4: Remove unnecessary quota functions
ext4_dquot_initialize() and ext4_dquot_drop() is no longer
needed because of modified quota locking.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:34 +01:00
Jan Kara
a219ce3748 ext3: Remove unnecessary quota functions
ext3_dquot_initialize() and ext3_dquot_drop() is no longer
needed because of modified quota locking.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:34 +01:00
Mingming Cao
08d0350ce9 quota: Move EXPORT_SYMBOL immediately next to the functions/varibles
According to checkpatch: EXPORT_SYMBOL(foo); should immediately follow its
 function/variable

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:34 +01:00
Mingming Cao
740d9dcd94 quota: Add quota reservation claim and released operations
Reserved quota will be claimed at the block allocation time. Over-booked
quota could be returned back with the release callback function.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:24 +01:00
Mingming Cao
f18df22899 quota: Add quota reservation support
Delayed allocation defers the block allocation at the dirty pages
flush-out time, doing quota charge/check at that time is too late.
But we can't charge the quota blocks until blocks are really allocated,
otherwise users could get overcharged after reboot from system crash.

This patch adds quota reservation for delayed allocation. Quota blocks
are reserved in memory, inode and quota won't gets dirtied until later
block allocation time.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:15:50 +01:00
Chris Mason
1a81af4d1d Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod
btrfs_update_delayed_ref is optimized to add and remove different
references in one pass through the delayed ref tree.  It is a zero
sum on the total number of refs on a given extent.

But, the code was recording an extra ref in the head node.  This
never made it down to the disk but was used when deciding if it was
safe to free the extent while dropping snapshots.

The fix used here is to make sure the ref_mod count is unchanged
on the head ref when btrfs_update_delayed_ref is called.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-25 09:55:11 -04:00