Commit Graph

2788 Commits (561c294d4cfb30c4acfa0a243448fc55af730d87)

Author SHA1 Message Date
Miao Xie 561c294d4c Btrfs: fix wrong comment in can_overcommit()
The comment is not coincident with the code. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-12-11 13:31:30 -05:00
Miao Xie 3fed40cc97 Btrfs: cleanup duplicated division functions
div_factor{_fine} has been implemented for two times, cleanup it.
And I move them into a independent file named math.h because they are
common math functions.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-12-11 13:31:30 -05:00
Linus Torvalds f48d42773b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "This has our series of fixes for the next rc.  The biggest batch is
  from Jan Schmidt, fixing up some problems in our subvolume quota code
  and fixing btrfs send/receive to work with the new extended inode
  refs."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: do not bug when we fail to commit the transaction
  Btrfs: fix memory leak when cloning root's node
  Btrfs: Use btrfs_update_inode_fallback when creating a snapshot
  Btrfs: Send: preserve ownership (uid and gid) also for symlinks.
  Btrfs: fix deadlock caused by the nested chunk allocation
  btrfs: Return EINVAL when length to trim is less than FSB
  Btrfs: fix memory leak in btrfs_quota_enable()
  Btrfs: send correct rdev and mode in btrfs-send
  Btrfs: extended inode refs support for send mechanism
  Btrfs: Fix wrong error handling code
  Fix a sign bug causing invalid memory access in the ino_paths ioctl.
  Btrfs: comment for loop in tree_mod_log_insert_move
  Btrfs: fix extent buffer reference for tree mod log roots
  Btrfs: determine level of old roots
  Btrfs: tree mod log's old roots could still be part of the tree
  Btrfs: fix a tree mod logging issue for root replacement operations
  Btrfs: don't put removals from push_node_left into tree mod log twice
2012-10-26 09:34:04 -07:00
Josef Bacik c37b2b6269 Btrfs: do not bug when we fail to commit the transaction
We BUG if we fail to commit the transaction when creating a snapshot, which
is just obnoxious.  Remove the BUG_ON().  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-25 15:59:57 -04:00
Liu Bo 7bfdcf7fba Btrfs: fix memory leak when cloning root's node
After cloning root's node, we forgot to dec the src's ref
which can lead to a memory leak.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-10-25 15:55:21 -04:00
Chris Mason c657c3ef1a Merge branch 'for-chris-fixed' of git://git.jan-o-sch.net/btrfs-unstable 2012-10-25 15:53:10 -04:00
Josef Bacik be6aef6049 Btrfs: Use btrfs_update_inode_fallback when creating a snapshot
On a really full file system I was getting ENOSPC back from
btrfs_update_inode when trying to update the parent inode when creating a
snapshot.  Just use the fallback method so we can update the inode and not
have to worry about having a delayed ref.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-25 15:50:18 -04:00
Alex Lyakas e2d044fe77 Btrfs: Send: preserve ownership (uid and gid) also for symlinks.
This patch also requires a change in the user-space part of "receive".
We need to use "lchown" instead of "chown". We will do this in the
following patch.

Signed-off-by: Alex Lyakas <alex.btrfs@zadarastorage.com>

 	if (S_ISREG(sctx->cur_inode_mode)) {
2012-10-25 15:47:31 -04:00
Miao Xie 671415b7db Btrfs: fix deadlock caused by the nested chunk allocation
Steps to reproduce:
 # mkfs.btrfs -m raid1 <disk1> <disk2>
 # btrfstune -S 1 <disk1>
 # mount <disk1> <mnt>
 # btrfs device add <disk3> <disk4> <mnt>
 # mount -o remount,rw <mnt>
 # dd if=/dev/zero of=<mnt>/tmpfile bs=1M count=1
 Deadlock happened.

It is because of the nested chunk allocation. When we wrote the data
into the filesystem, we would allocate the data chunk because there was
no data chunk in the filesystem. At the end of the data chunk allocation,
we should insert the metadata of the data chunk into the extent tree, but
there was no raid1 chunk, so we tried to lock the chunk allocation mutex to
allocate the new chunk, but we had held the mutex, the deadlock happened.

By rights, we would allocate the raid1 chunk when we added the second device
because the profile of the seed filesystem is raid1 and we had two devices.
But we didn't do that in fact. It is because the last step of the first device
insertion didn't commit the transaction. So when we added the second device,
we didn't cow the tree, and just inserted the relative metadata into the leaves
which were generated by the first device insertion, and its profile was dup.

So, I fix this problem by commiting the transaction at the end of the first
device insertion.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2012-10-25 15:47:00 -04:00
Lukas Czerner e515c18bfe btrfs: Return EINVAL when length to trim is less than FSB
Currently if len argument in btrfs_ioctl_fitrim() is smaller than
one FSB we will continue and finally return 0 bytes discarded.
However if the length to discard is smaller then file system block
we should really return EINVAL.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
2012-10-25 15:46:22 -04:00
Tsutomu Itoh 5b7ff5b3c4 Btrfs: fix memory leak in btrfs_quota_enable()
We should free quota_root before returning from the error
handling code.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
2012-10-25 15:45:43 -04:00
Arne Jansen d79e50433b Btrfs: send correct rdev and mode in btrfs-send
When sending a device file, the stream was missing the mode. Also the
rdev was encoded wrongly.

Signed-off-by: Arne Jansen <sensille@gmx.net>
2012-10-25 15:45:25 -04:00
Jan Schmidt 96b5bd7771 Btrfs: extended inode refs support for send mechanism
This adds support for the new extended inode refs to btrfs send.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-25 15:45:16 -04:00
Stefan Behrens 84167d1905 Btrfs: Fix wrong error handling code
gcc says "warning: comparison of unsigned expression >= 0 is always
true" because i is an unsigned long. And gcc is right this time.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
2012-10-25 15:40:03 -04:00
Gabriel de Perthuis 661bec6ba8 Fix a sign bug causing invalid memory access in the ino_paths ioctl.
To see the problem, create many hardlinks to the same file (120 should do it),
then look up paths by inode with:

  ls -i
  btrfs inspect inode-resolve -v $ino /mnt/btrfs

I noticed the memory layout of the fspath->val data had some irregularities
(some unnecessary gaps that stop appearing about halfway),
so I'm not sure there aren't any bugs left in it.
2012-10-25 15:39:47 -04:00
Jan Schmidt 01763a2e37 Btrfs: comment for loop in tree_mod_log_insert_move
Emphasis the way tree_mod_log_insert_move avoids adding
MOD_LOG_KEY_REMOVE_WHILE_MOVING operations, depending on the direction of
the move operation.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-24 12:36:40 +02:00
Jan Schmidt d638108484 Btrfs: fix extent buffer reference for tree mod log roots
In get_old_root we grab a lock on the extent buffer before we obtain a
reference on that buffer. That order is changed now.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-24 12:36:39 +02:00
Jan Schmidt 5b6602e762 Btrfs: determine level of old roots
In btrfs_find_all_roots' termination condition, we compare the level of the
old buffer we got from btrfs_search_old_slot to the level of the current
root node. We'd better compare it to the level of the rewinded root node.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-24 12:36:38 +02:00
Jan Schmidt 834328a849 Btrfs: tree mod log's old roots could still be part of the tree
Tree mod log treated old root buffers as always empty buffers when starting
the rewind operations. However, the old root may still be part of the
current tree at a lower level, with still some valid entries.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-24 12:36:37 +02:00
Jan Schmidt ba1bfbd592 Btrfs: fix a tree mod logging issue for root replacement operations
Avoid the implicit free by tree_mod_log_set_root_pointer, which is wrong in
two places. Where needed, we call tree_mod_log_free_eb explicitly now.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-23 15:09:14 +02:00
Jan Schmidt 57911b8ba8 Btrfs: don't put removals from push_node_left into tree mod log twice
Independant of the check (push_items < src_items) tree_mod_log_eb_copy did
log the removal of the old data entries from the source buffer. Therefore,
we must not call tree_mod_log_eb_move if the check evaluates to true, as
that would log the removal twice, finally resulting in (rewinded) buffers
with wrong values for header_nritems.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-10-23 15:09:11 +02:00
Linus Torvalds 09a9ad6a1f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace compile fixes from Eric W Biederman:
 "This tree contains three trivial fixes.  One compiler warning, one
  thinko fix, and one build fix"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  btrfs: Fix compilation with user namespace support enabled
  userns: Fix posix_acl_file_xattr_userns gid conversion
  userns: Properly print bluetooth socket uids
2012-10-13 13:23:39 -07:00
Eric W. Biederman e9069f4708 btrfs: Fix compilation with user namespace support enabled
When compiling with user namespace support btrfs fails like:

fs/btrfs/tree-log.c: In function ‘fill_inode_item’:
fs/btrfs/tree-log.c:2955:2: error: incompatible type for argument 3 of ‘btrfs_set_inode_uid’
fs/btrfs/ctree.h:2026:1: note: expected ‘u32’ but argument is of type ‘kuid_t’
fs/btrfs/tree-log.c:2956:2: error: incompatible type for argument 3 of ‘btrfs_set_inode_gid’
fs/btrfs/ctree.h:2027:1: note: expected ‘u32’ but argument is of type ‘kgid_t’

Fix this by using i_uid_read and i_gid_read in

Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-10-12 15:01:42 -07:00
Jeff Layton 4fa6b5ecbf audit: overhaul __audit_inode_child to accomodate retrying
In order to accomodate retrying path-based syscalls, we need to add a
new "type" argument to audit_inode_child. This will tell us whether
we're looking for a child entry that represents a create or a delete.

If we find a parent, don't automatically assume that we need to create a
new entry. Instead, use the information we have to try to find an
existing entry first. Update it if one is found and create a new one if
not.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 00:32:03 -04:00
Jeff Layton c43a25abba audit: reverse arguments to audit_inode_child
Most of the callers get called with an inode and dentry in the reverse
order. The compiler then has to reshuffle the arg registers and/or
stack in order to pass them on to audit_inode_child.

Reverse those arguments for a micro-optimization.

Reported-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 00:32:00 -04:00
Linus Torvalds 72055425e5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs update from Chris Mason:
 "This is a large pull, with the bulk of the updates coming from:

   - Hole punching

   - send/receive fixes

   - fsync performance

   - Disk format extension allowing more hardlinks inside a single
     directory (btrfs-progs patch required to enable the compat bit for
     this one)

  I'm cooking more unrelated RAID code, but I wanted to make sure this
  original batch makes it in.  The largest updates here are relatively
  old and have been in testing for some time."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (121 commits)
  btrfs: init ref_index to zero in add_inode_ref
  Btrfs: remove repeated eb->pages check in, disk-io.c/csum_dirty_buffer
  Btrfs: fix page leakage
  Btrfs: do not warn_on when we cannot alloc a page for an extent buffer
  Btrfs: don't bug on enomem in readpage
  Btrfs: cleanup pages properly when ENOMEM in compression
  Btrfs: make filesystem read-only when submitting barrier fails
  Btrfs: detect corrupted filesystem after write I/O errors
  Btrfs: make compress and nodatacow mount options mutually exclusive
  btrfs: fix message printing
  Btrfs: don't bother committing delayed inode updates when fsyncing
  btrfs: move inline function code to header file
  Btrfs: remove unnecessary IS_ERR in bio_readpage_error()
  btrfs: remove unused function btrfs_insert_some_items()
  Btrfs: don't commit instead of overcommitting
  Btrfs: confirmation of value is added before trace_btrfs_get_extent() is called
  Btrfs: be smarter about dropping things from the tree log
  Btrfs: don't lookup csums for prealloc extents
  Btrfs: cache extent state when writing out dirty metadata pages
  Btrfs: do not hold the file extent leaf locked when adding extent item
  ...
2012-10-10 10:49:20 +09:00
Chris Mason f46dbe3dee btrfs: init ref_index to zero in add_inode_ref
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-10-09 11:17:20 -04:00
Wang Sheng-Hui 1037a5affc Btrfs: remove repeated eb->pages check in, disk-io.c/csum_dirty_buffer
In csum_dirty_buffer, we first get eb from page->private.
Then we check if the page is the first page of eb. Later
we check it again. Remove the repeated check here.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
2012-10-09 09:37:30 -04:00
Josef Bacik f60b1b49f6 Btrfs: fix page leakage
Alloc_dummy_extent_buffer will not free the first page in the eb array if we
fail to allocate a page, fix this.  Thanks,

Reported-by: David Sterba <dave@jikos.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:20:56 -04:00
Josef Bacik 4804b38293 Btrfs: do not warn_on when we cannot alloc a page for an extent buffer
It's just annoying and the user will have gotten a nice OOM killer message
so they are already fully aware they are screwed :).  Thanks,

Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:20:43 -04:00
Josef Bacik edd33c99c4 Btrfs: don't bug on enomem in readpage
Get rid of the BUG_ON(ret == -ENOMEM) in __extent_read_full_page.  Thanks,

Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:20:31 -04:00
Josef Bacik 15e3004a0e Btrfs: cleanup pages properly when ENOMEM in compression
We were freeing non-existent pages which was causing a panic for a user who
was suffering from ENOMEM.  This patch fixes the problem.  Thanks,

Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:20:25 -04:00
Stefan Behrens 5af3e8cce8 Btrfs: make filesystem read-only when submitting barrier fails
So far the return code of barrier_all_devices() is ignored, which
means that errors are ignored. The result can be a corrupt
filesystem which is not consistent.
This commit adds code to evaluate the return code of
barrier_all_devices(). The normal btrfs_error() mechanism is used to
switch the filesystem into read-only mode when errors are detected.

In order to decide whether barrier_all_devices() should return
error or success, the number of disks that are allowed to fail the
barrier submission is calculated. This calculation accounts for the
worst RAID level of metadata, system and data. If single, dup or
RAID0 is in use, a single disk error is already considered to be
fatal. Otherwise a single disk error is tolerated.

The calculation of the number of disks that are tolerated to fail
the barrier operation is performed when the filesystem gets mounted,
when a balance operation is started and finished, and when devices
are added or removed.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
2012-10-09 09:20:19 -04:00
Stefan Behrens 62856a9b73 Btrfs: detect corrupted filesystem after write I/O errors
In check-integrity, detect when a superblock is written that points
to blocks that have not been written to disk due to I/O write errors.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
2012-10-09 09:20:10 -04:00
Andrei Popa bedb2cca72 Btrfs: make compress and nodatacow mount options mutually exclusive
If a filesystem is mounted with compression and then remounted by adding nodatacow,
the compression is disabled but the compress flag is still visible.
Also, if a filesystem is mounted with nodatacow and then remounted with compression,
nodatacow flag is still present but it's not active.
This patch:
- removes compress flags and notifies that the compression has been disabled if the
  filesystem is mounted with nodatacow
- removes nodatacow and nodatasum flags if mounted with compress.

Signed-off-by: Andrei Popa <andrei.popa@i-neo.ro>
2012-10-09 09:20:03 -04:00
Daniel J Blueman 489406626c btrfs: fix message printing
Fix various messages to include newline and module prefix.

Signed-off-by: Daniel J Blueman <daniel@quora.org>
2012-10-09 09:19:57 -04:00
Josef Bacik 94edf4ae43 Btrfs: don't bother committing delayed inode updates when fsyncing
We can just copy the in memory inode into the tree log directly, no sense in
updating the fs tree so we can copy it into the tree log tree.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:19:50 -04:00
Robin Dong 479ed9abdb btrfs: move inline function code to header file
When building btrfs from kernel code, it will report:

	fs/btrfs/extent_io.h:281: warning: 'extent_buffer_page' declared inline after being called
	fs/btrfs/extent_io.h:281: warning: previous declaration of 'extent_buffer_page' was here
	fs/btrfs/extent_io.h:280: warning: 'num_extent_pages' declared inline after being called
	fs/btrfs/extent_io.h:280: warning: previous declaration of 'num_extent_pages' was here

because of the wrong declaration of inline functions.

Signed-off-by: Robin Dong <sanbai@taobao.com>
2012-10-09 09:15:43 -04:00
Tsutomu Itoh 7a2d6a6464 Btrfs: remove unnecessary IS_ERR in bio_readpage_error()
Because the value of extent_map is only a correct value or NULL,
so IS_ERR is unnecessary.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
2012-10-09 09:15:43 -04:00
Robin Dong 8d1a1317af btrfs: remove unused function btrfs_insert_some_items()
The function btrfs_insert_some_items() would not be called by any other functions,
so remove it.

Signed-off-by: Robin Dong <sanbai@taobao.com>
2012-10-09 09:15:43 -04:00
Josef Bacik 44734ed1ca Btrfs: don't commit instead of overcommitting
I don't think we have the same problem that this was supposed to fix
originally since we can allocate chunks in the enospc path now.  This code
is causing us to constantly commit the transaction as we get close to using
all of our available space in our currently allocated chunks, instead of
allocating another chunk and carrying on with life, which is not nice for
performance.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:42 -04:00
Tsutomu Itoh f0bd95ea72 Btrfs: confirmation of value is added before trace_btrfs_get_extent() is called
We should confirm the value of extent_map before calling
trace_btrfs_get_extent() because the value of extent_map has the
possibility of NULL.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
2012-10-09 09:15:42 -04:00
Josef Bacik 18ec90d63f Btrfs: be smarter about dropping things from the tree log
When we truncate existing items in the tree log we've been searching for
each individual item and removing them.  This is unnecessary churn and
searching, just keep track of the slot we are on and how many items we need
to delete and delete them all at once.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:41 -04:00
Josef Bacik 6f1fed7753 Btrfs: don't lookup csums for prealloc extents
The tree logging stuff was looking up csums to copy over for prealloc
extents which is just work we don't need to be doing.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:41 -04:00
Josef Bacik e6138876ad Btrfs: cache extent state when writing out dirty metadata pages
Everytime we write out dirty pages we search for an offset in the tree,
convert the bits in the state, and then when we wait we search for the
offset again and clear the bits.  So for every dirty range in the io tree we
are doing 4 rb searches, which is suboptimal.  With this patch we are only
doing 2 searches for every cycle (modulo weird things happening).  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:41 -04:00
Josef Bacik ce19533256 Btrfs: do not hold the file extent leaf locked when adding extent item
For some reason we unlock everything except the leaf we are on, set the path
blocking and then add the extent item for the extent we just finished
writing.  I can't for the life of me figure out why we would want to do
this, and the history doesn't really indicate that there was a real reason
for it, so just remove it.  This will reduce our tree lock contention on
heavy writes.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:40 -04:00
Josef Bacik de0022b9da Btrfs: do not async metadata csumming in certain situations
There are a coule scenarios where farming metadata csumming off to an async
thread doesn't help.  The first is if our processor supports crc32c, in
which case the csumming will be fast and so the overhead of the async model
is not worth the cost.  The other case is for our tree log.  We will be
making that stuff dirty and writing it out and waiting for it immediately.
Even with software crc32c this gives me a ~15% increase in speed with O_SYNC
workloads.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:40 -04:00
Zach Brown 221b831835 btrfs: fix min csum item size warnings in 32bit
commit 7ca4be45a0 limited csum items to
PAGE_CACHE_SIZE.  It used min() with incompatible types in 32bit which
generates warnings:

fs/btrfs/file-item.c: In function ‘btrfs_csum_file_blocks’:
fs/btrfs/file-item.c:717: warning: comparison of distinct pointer types lacks a cast

This uses min_t(u32,) to fix the warnings.  u32 seemed reasonable
because btrfs_root->leafsize is u32 and PAGE_CACHE_SIZE is unsigned
long.

Signed-off-by: Zach Brown <zab@zabbo.net>
2012-10-09 09:15:39 -04:00
Josef Bacik 67b0fd63d5 Btrfs: run delayed refs first when out of space
Running delayed refs is faster than running delalloc, so lets do that first
to try and reclaim space.  This makes my fs_mark test about 20% faster.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-09 09:15:39 -04:00
Miao Xie 354aa0fb6d Btrfs: fix orphan transaction on the freezed filesystem
With the following debug patch:

 static int btrfs_freeze(struct super_block *sb)
 {
+ 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_transaction *trans;
+
+	spin_lock(&fs_info->trans_lock);
+	trans = fs_info->running_transaction;
+	if (trans) {
+		printk("Transid %llu, use_count %d, num_writer %d\n",
+			trans->transid, atomic_read(&trans->use_count),
+			atomic_read(&trans->num_writers));
+	}
+	spin_unlock(&fs_info->trans_lock);
 	return 0;
 }

I found there was a orphan transaction after the freeze operation was done.

It is because the transaction may not be committed when the transaction handle
end even though it is the last handle of the current transaction. This design
avoid committing the transaction frequently, but also introduce the above
problem.

So I add btrfs_attach_transaction() which can catch the current transaction
and commit it. If there is no transaction, it will return ENOENT, and do not
anything.

This function also can be used to instead of btrfs_join_transaction_freeze()
because it don't increase the writer counter and don't start a new transaction,
so it also can fix the deadlock between sync and freeze.

Besides that, it is used to instead of btrfs_join_transaction() in
transaction_kthread(), because if there is no transaction, the transaction
kthread needn't anything.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2012-10-09 09:15:39 -04:00