Btrfs: fix warning of bytes_may_use

While running generic/019, dmesg got several warnings from
btrfs_free_reserved_data_space().

Test generic/019 produces some disk failures so sumbit dio will get

Btrfs: fix warning of bytes_may_use

While running generic/019, dmesg got several warnings from
btrfs_free_reserved_data_space().

Test generic/019 produces some disk failures so sumbit dio will get errors,
in which case, btrfs_direct_IO() goes to the error handling and free
bytes_may_use, but the problem is that bytes_may_use has been free'd
during get_block().

This adds a runtime flag to show if we've gone through get_block(), if so,
don't do the cleanup work.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: fix metadata inconsistencies after directory fsync

We can get into inconsistency between inodes and directory entries
after fsyncing a directory. The issue is that while a directory gets
the

Btrfs: fix metadata inconsistencies after directory fsync

We can get into inconsistency between inodes and directory entries
after fsyncing a directory. The issue is that while a directory gets
the new dentries persisted in the fsync log and replayed at mount time,
the link count of the inode that directory entries point to doesn't
get updated, staying with an incorrect link count (smaller then the
correct value). This later leads to stale file handle errors when
accessing (including attempt to delete) some of the links if all the
other ones are removed, which also implies impossibility to delete the
parent directories, since the dentries can not be removed.

Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2),
when fsyncing a directory, new files aren't logged (their metadata and
dentries) nor any child directories. So this patch fixes this issue too,
since it has the same resolution as the incorrect inode link count issue
mentioned before.

This is very easy to reproduce, and the following excerpt from my test
case for xfstests shows how:

_scratch_mkfs >> $seqres.full 2>&1
_init_flakey
_mount_flakey

# Create our main test file and directory.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io
mkdir $SCRATCH_MNT/mydir

# Make sure all metadata and data are durably persisted.
sync

# Add a hard link to 'foo' inside our test directory and fsync only the
# directory. The btrfs fsync implementation had a bug that caused the new
# directory entry to be visible after the fsync log replay but, the inode
# of our file remained with a link count of 1.
ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2

# Add a few more links and new files.
# This is just to verify nothing breaks or gives incorrect results after the
# fsync log is replayed.
ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3
$XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io
ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2

# Add some subdirectories and new files and links to them. This is to verify
# that after fsyncing our top level directory 'mydir', all the subdirectories
# and their files/links are registered in the fsync log and exist after the
# fsync log is replayed.
mkdir -p $SCRATCH_MNT/mydir/x/y/z
ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link
ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link
touch $SCRATCH_MNT/mydir/x/y/z/qwerty

# Now fsync only our top directory.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir

# And fsync now our new file named 'hello', just to verify later that it has
# the expected content and that the previous fsync on the directory 'mydir' had
# no bad influence on this fsync.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello

# Simulate a crash/power loss.
_load_flakey_table $FLAKEY_DROP_WRITES
_unmount_flakey

_load_flakey_table $FLAKEY_ALLOW_WRITES
_mount_flakey

# Verify the content of our file 'foo' remains the same as before, 8192 bytes,
# all with the value 0xaa.
echo "File 'foo' content after log replay:"
od -t x1 $SCRATCH_MNT/foo

# Remove the first name of our inode. Because of the directory fsync bug, the
# inode's link count was 1 instead of 5, so removing the 'foo' name ended up
# deleting the inode and the other names became stale directory entries (still
# visible to applications). Attempting to remove or access the remaining
# dentries pointing to that inode resulted in stale file handle errors and
# made it impossible to remove the parent directories since it was impossible
# for them to become empty.
echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)"
rm -f $SCRATCH_MNT/foo

# Now verify that all files, links and directories created before fsyncing our
# directory exist after the fsync log was replayed.
[ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing"
[ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing"
[ -f $SCRATCH_MNT/hello ] || echo "File hello is missing"
[ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing"
[ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \
echo "Link mydir/x/y/foo_y_link is missing"
[ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \
echo "Link mydir/x/y/z/foo_z_link is missing"
[ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \
echo "File mydir/x/y/z/qwerty is missing"

# We expect our file here to have a size of 64Kb and all the bytes having the
# value 0xff.
echo "file 'hello' content after log replay:"
od -t x1 $SCRATCH_MNT/hello

# Now remove all files/links, under our test directory 'mydir', and verify we
# can remove all the directories.
rm -f $SCRATCH_MNT/mydir/x/y/z/*
rmdir $SCRATCH_MNT/mydir/x/y/z
rm -f $SCRATCH_MNT/mydir/x/y/*
rmdir $SCRATCH_MNT/mydir/x/y
rmdir $SCRATCH_MNT/mydir/x
rm -f $SCRATCH_MNT/mydir/*
rmdir $SCRATCH_MNT/mydir

# An fsck, run by the fstests framework everytime a test finishes, also detected
# the inconsistency and printed the following error message:
#
# root 5 inode 257 errors 2001, no inode item, link count wrong
# unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref
# unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref

status=0
exit

The expected golden output for the test is:

wrote 8192/8192 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 65536/65536 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
File 'foo' content after log replay:
0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
*
0020000
file 'foo' link count after log replay: 5
file 'hello' content after log replay:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0200000

Which is the output after this patch and when running the test against
ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's
output is:

wrote 8192/8192 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 65536/65536 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
File 'foo' content after log replay:
0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
*
0020000
file 'foo' link count after log replay: 1
Link mydir/foo_2 is missing
Link mydir/foo_3 is missing
Link mydir/x/y/foo_y_link is missing
Link mydir/x/y/z/foo_z_link is missing
File mydir/x/y/z/qwerty is missing
file 'hello' content after log replay:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0200000
rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory
rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory
rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory
rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle
rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle
rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty

Fsck, without this fix, also complains about the wrong link count:

root 5 inode 257 errors 2001, no inode item, link count wrong
unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref
unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref

So fix this by logging the inodes that the dentries point to when
fsyncing a directory.

A test case for xfstests follows.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: Add code to support file creation time

This patch adds a new member to the 'struct btrfs_inode' structure to hold
the file creation time.

Signed-off-by: chandan <chandanrmail@gmail.com>
[ref

Btrfs: Add code to support file creation time

This patch adds a new member to the 'struct btrfs_inode' structure to hold
the file creation time.

Signed-off-by: chandan <chandanrmail@gmail.com>
[refreshed, removed btrfs_inode_otime]
Signed-off-by: David Sterba <dsterba@suse.cz>

Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: be aware of btree inode write errors to avoid fs corruption

While we have a transaction ongoing, the VM might decide at any time
to call btree_inode->i_mapping->a_ops->writepages(), which wil

Btrfs: be aware of btree inode write errors to avoid fs corruption

While we have a transaction ongoing, the VM might decide at any time
to call btree_inode->i_mapping->a_ops->writepages(), which will start
writeback of dirty pages belonging to btree nodes/leafs. This call
might return an error or the writeback might finish with an error
before we attempt to commit the running transaction. If this happens,
we might have no way of knowing that such error happened when we are
committing the transaction - because the pages might no longer be
marked dirty nor tagged for writeback (if a subsequent modification
to the extent buffer didn't happen before the transaction commit) which
makes filemap_fdata[write|wait]_range unable to find such pages (even
if they're marked with SetPageError).
So if this happens we must abort the transaction, otherwise we commit
a super block with btree roots that point to btree nodes/leafs whose
content on disk is invalid - either garbage or the content of some
node/leaf from a past generation that got cowed or deleted and is no
longer valid (for this later case we end up getting error messages like
"parent transid verify failed on 10826481664 wanted 25748 found 29562"
when reading btree nodes/leafs from disk).

Note that setting and checking AS_EIO/AS_ENOSPC in the btree inode's
i_mapping would not be enough because we need to distinguish between
log tree extents (not fatal) vs non-log tree extents (fatal) and
because the next call to filemap_fdatawait_range() will catch and clear
such errors in the mapping - and that call might be from a log sync and
not from a transaction commit, which means we would not know about the
error at transaction commit time. Also, checking for the eb flag
EXTENT_BUFFER_IOERR at transaction commit time isn't done and would
not be completely reliable, as the eb might be removed from memory and
read back when trying to get it, which clears that flag right before
reading the eb's pages from disk, making us not know about the previous
write error.

Using the new 3 flags for the btree inode also makes us achieve the
goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
writeback for all dirty pages and before filemap_fdatawait_range() is
called, the writeback for all dirty pages had already finished with
errors - because we were not using AS_EIO/AS_ENOSPC,
filemap_fdatawait_range() would return success, as it could not know
that writeback errors happened (the pages were no longer tagged for
writeback).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: implement repair function when direct read fails

This patch implement data repair function when direct read fails.

The detail of the implementation is:
- When we find the data is not right,

Btrfs: implement repair function when direct read fails

This patch implement data repair function when direct read fails.

The detail of the implementation is:
- When we find the data is not right, we try to read the data from the other
mirror.
- When the io on the mirror ends, we will insert the endio work into the
dedicated btrfs workqueue, not common read endio workqueue, because the
original endio work is still blocked in the btrfs endio workqueue, if we
insert the endio work of the io on the mirror into that workqueue, deadlock
would happen.
- After we get right data, we write it back to the corrupted mirror.
- And if the data on the new mirror is still corrupted, we will try next
mirror until we read right data or all the mirrors are traversed.
- After the above work, we set the uptodate flag according to the result.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: do file data check by sub-bio's self

Direct IO splits the original bio to several sub-bios because of the limit of
raid stripe, and the filesystem will wait for all sub-bios and then run fina

Btrfs: do file data check by sub-bio's self

Direct IO splits the original bio to several sub-bios because of the limit of
raid stripe, and the filesystem will wait for all sub-bios and then run final
end io process.

But it was very hard to implement the data repair when dio read failure happens,
because at the final end io function, we didn't know which mirror the data was
read from. So in order to implement the data repair, we have to move the file data
check in the final end io function to the sub-bio end io function, in which we can
get the mirror number of the device we access. This patch did this work as the
first step of the direct io data repair implementation.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: load checksum data once when submitting a direct read io

The current code would load checksum data for several times when we split
a whole direct read io because of the limit of the raid stri

Btrfs: load checksum data once when submitting a direct read io

The current code would load checksum data for several times when we split
a whole direct read io because of the limit of the raid stripe, it would
make us search the csum tree for several times. In fact, it just wasted time,
and made the contention of the csum tree root be more serious. This patch
improves this problem by loading the data at once.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: make defragment work with nodatacow option

Btrfs defragment will utilize COW feature, which means this
did not work for nodatacow option, this problem was detected
by xfstests generic/018 wit

Btrfs: make defragment work with nodatacow option

Btrfs defragment will utilize COW feature, which means this
did not work for nodatacow option, this problem was detected
by xfstests generic/018 with nodatacow mount option.

Fix this problem by forcing cow for a extent with state
@EXTETN_DEFRAG setting.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: set inode's logged_trans/last_log_commit after ranged fsync

When a ranged fsync finishes if there are still extent maps in the modified
list, still set the inode's logged_trans and last_log_c

Btrfs: set inode's logged_trans/last_log_commit after ranged fsync

When a ranged fsync finishes if there are still extent maps in the modified
list, still set the inode's logged_trans and last_log_commit. This is important
in case an inode is fsync'ed and unlinked in the same transaction, to ensure its
inode ref gets deleted from the log and the respective dentries in its parent
are deleted too from the log (if the parent directory was fsync'ed in the same
transaction).

Instead make btrfs_inode_in_log() return false if the list of modified extent
maps isn't empty.

This is an incremental on top of the v4 version of the patch:

"Btrfs: fix fsync data loss after a ranged fsync"

which was added to its v5, but didn't make it on time.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

btrfs: disable strict file flushes for renames and truncates

Truncates and renames are often used to replace old versions of a file
with new versions. Applications often expect this to be an atomic

btrfs: disable strict file flushes for renames and truncates

Truncates and renames are often used to replace old versions of a file
with new versions. Applications often expect this to be an atomic
replacement, even if they haven't done anything to make sure the new
version is fully on disk.

Btrfs has strict flushing in place to make sure that renaming over an
old file with a new file will fully flush out the new file before
allowing the transaction commit with the rename to complete.

This ordering means the commit code needs to be able to lock file pages,
and there are a few paths in the filesystem where we will try to end a
transaction with the page lock held. It's rare, but these things can
deadlock.

This patch removes the ordered flushes and switches to a best effort
filemap_flush like ext4 uses. It's not perfect, but it should fix the
deadlocks.

Signed-off-by: Chris Mason <clm@fb.com>

show more ...

btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking

In these instances, we are trying to determine if a page has been accessed
since we began the operation for the sake of retry.

btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking

In these instances, we are trying to determine if a page has been accessed
since we began the operation for the sake of retry. This is easily
accomplished by doing a gang lookup in the page mapping radix tree, and it
saves us the dependency on the flag (so that we might eventually delete
it).

btrfs_page_exists_in_range borrows heavily from find_get_page, replacing
the radix tree look up with a gang lookup of 1, so that we can find the
next highest page >= index and see if it falls into our lock range.

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Alex Gartrell <agartrell@fb.com>

show more ...

arch: Mass conversion of smp_mb__*()

Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.co

arch: Mass conversion of smp_mb__*()

Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

Btrfs: use signed integer instead of unsigned long integer for log transid

The log trans id is initialized to be 0 every time we create a log tree,
and the log tree need be re-created after a new tr

Btrfs: use signed integer instead of unsigned long integer for log transid

The log trans id is initialized to be 0 every time we create a log tree,
and the log tree need be re-created after a new transaction is started,
it means the log trans id is unlikely to be a huge number, so we can use
signed integer instead of unsigned long integer to save a bit space.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>

show more ...

Btrfs: add support for inode properties

This change adds infrastructure to allow for generic properties for
inodes. Properties are name/value pairs that can be associated with
inodes for different p

Btrfs: add support for inode properties

This change adds infrastructure to allow for generic properties for
inodes. Properties are name/value pairs that can be associated with
inodes for different purposes. They are stored as xattrs with the
prefix "btrfs."

Properties can be inherited - this means when a directory inode has
inheritable properties set, these are added to new inodes created
under that directory. Further, subvolumes can also have properties
associated with them, and they can be inherited from their parent
subvolume. Naturally, directory properties have priority over subvolume
properties (in practice a subvolume property is just a regular
property associated with the root inode, objectid 256, of the
subvolume's fs tree).

This change also adds one specific property implementation, named
"compression", whose values can be "lzo" or "zlib" and it's an
inheritable property.

The corresponding changes to btrfs-progs were also implemented.
A patch with xfstests for this feature will follow once there's
agreement on this change/feature.

Further, the script at the bottom of this commit message was used to
do some benchmarks to measure any performance penalties of this feature.

Basically the tests correspond to:

Test 1 - create a filesystem and mount it with compress-force=lzo,
then sequentially create N files of 64Kb each, measure how long it took
to create the files, unmount the filesystem, mount the filesystem and
perform an 'ls -lha' against the test directory holding the N files, and
report the time the command took.

Test 2 - create a filesystem and don't use any compression option when
mounting it - instead set the compression property of the subvolume's
root to 'lzo'. Then create N files of 64Kb, and report the time it took.
The unmount the filesystem, mount it again and perform an 'ls -lha' like
in the former test. This means every single file ends up with a property
(xattr) associated to it.

Test 3 - same as test 2, but uses 4 properties - 3 are duplicates of the
compression property, have no real effect other than adding more work
when inheriting properties and taking more btree leaf space.

Test 4 - same as test 3 but with 10 properties per file.

Results (in seconds, and averages of 5 runs each), for different N
numbers of files follow.

* Without properties (test 1)

file creation time ls -lha time
10 000 files 3.49 0.76
100 000 files 47.19 8.37
1 000 000 files 518.51 107.06

* With 1 property (compression property set to lzo - test 2)

file creation time ls -lha time
10 000 files 3.63 0.93
100 000 files 48.56 9.74
1 000 000 files 537.72 125.11

* With 4 properties (test 3)

file creation time ls -lha time
10 000 files 3.94 1.20
100 000 files 52.14 11.48
1 000 000 files 572.70 142.13

* With 10 properties (test 4)

file creation time ls -lha time
10 000 files 4.61 1.35
100 000 files 58.86 13.83
1 000 000 files 656.01 177.61

The increased latencies with properties are essencialy because of:

*) When creating an inode, we now synchronously write 1 more item
(an xattr item) for each property inherited from the parent dir
(or subvolume). This could be done in an asynchronous way such
as we do for dir intex items (delayed-inode.c), which could help
reduce the file creation latency;

*) With properties, we now have larger fs trees. For this particular
test each xattr item uses 75 bytes of leaf space in the fs tree.
This could be less by using a new item for xattr items, instead of
the current btrfs_dir_item, since we could cut the 'location' and
'type' fields (saving 18 bytes) and maybe 'transid' too (saving a
total of 26 bytes per xattr item) from the btrfs_dir_item type.

Also tried batching the xattr insertions (ignoring proper hash
collision handling, since it didn't exist) when creating files that
inherit properties from their parent inode/subvolume, but the end
results were (surprisingly) essentially the same.

Test script:

$ cat test.pl
#!/usr/bin/perl -w

use strict;
use Time::HiRes qw(time);
use constant NUM_FILES => 10_000;
use constant FILE_SIZES => (64 * 1024);
use constant DEV => '/dev/sdb4';
use constant MNT_POINT => '/home/fdmanana/btrfs-tests/dev';
use constant TEST_DIR => (MNT_POINT . '/testdir');

system("mkfs.btrfs", "-l", "16384", "-f", DEV) == 0 or die "mkfs.btrfs failed!";

# following line for testing without properties
#system("mount", "-o", "compress-force=lzo", DEV, MNT_POINT) == 0 or die "mount failed!";

# following 2 lines for testing with properties
system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";
system("btrfs", "prop", "set", MNT_POINT, "compression", "lzo") == 0 or die "set prop failed!";

system("mkdir", TEST_DIR) == 0 or die "mkdir failed!";
my ($t1, $t2);

$t1 = time();
for (my $i = 1; $i <= NUM_FILES; $i++) {
my $p = TEST_DIR . '/file_' . $i;
open(my $f, '>', $p) or die "Error opening file!";
$f->autoflush(1);
for (my $j = 0; $j < FILE_SIZES; $j += 4096) {
print $f ('A' x 4096) or die "Error writing to file!";
}
close($f);
}
$t2 = time();
print "Time to create " . NUM_FILES . ": " . ($t2 - $t1) . " seconds.\n";
system("umount", DEV) == 0 or die "umount failed!";
system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";

$t1 = time();
system("bash -c 'ls -lha " . TEST_DIR . " > /dev/null'") == 0 or die "ls failed!";
$t2 = time();
print "Time to ls -lha all files: " . ($t2 - $t1) . " seconds.\n";
system("umount", DEV) == 0 or die "umount failed!";

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: introduce the delayed inode ref deletion for the single link inode

The inode reference item is close to inode item, so we insert it simultaneously
with the inode item insertion when we create

Btrfs: introduce the delayed inode ref deletion for the single link inode

The inode reference item is close to inode item, so we insert it simultaneously
with the inode item insertion when we create a file/directory.. In fact, we also
can handle the inode reference deletion by the same way. So we made this patch to
introduce the delayed inode reference deletion for the single link inode(At most
case, the file doesn't has hard link, so we don't take the hard link into account).

This function is based on the delayed inode mechanism. After applying this patch,
we can reduce the time of the file/directory deletion by ~10%.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

show more ...

Btrfs: improve inode hash function/inode lookup

Currently the hash value used for adding an inode to the VFS's inode
hash table consists of the plain inode number, which is a 64 bits
integer. This r

Btrfs: improve inode hash function/inode lookup

Currently the hash value used for adding an inode to the VFS's inode
hash table consists of the plain inode number, which is a 64 bits
integer. This results in hash table buckets (hlist_head lists) with
too many elements for at least 2 important scenarios:

1) When we have many subvolumes. Each subvolume has its own btree
where its files and directories are added to, and each has its
own objectid (inode number) namespace. This means that if we have
N subvolumes, and all have inode number X associated to a file or
directory, the corresponding inodes all map to the same hash table
entry, resulting in a bucket (hlist_head list) with N elements;

2) On 32 bits machines. Th VFS hash values are unsigned longs, which
are 32 bits wide on 32 bits machines, and the inode (objectid)
numbers are 64 bits unsigned integers. We simply cast the inode
numbers to hash values, which means that for all inodes with the
same 32 bits lower half, the same hash bucket is used for all of
them. For example, all inodes with a number (objectid) between
0x0000_0000_ffff_ffff and 0xffff_ffff_ffff_ffff will end up in
the same hash table bucket.

This change ensures the inode's hash value depends both on the
objectid (inode number) and its subvolume's (btree root) objectid.
For 32 bits machines, this change gives better entropy by making
the hash value depend on both the upper and lower 32 bits of the
64 bits hash previously computed.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

show more ...

Btrfs: check roots last log commit when checking if an inode has been logged

Liu introduced a local copy of the last log commit for an inode to make sure we
actually log an inode even if a log commi

Btrfs: check roots last log commit when checking if an inode has been logged

Liu introduced a local copy of the last log commit for an inode to make sure we
actually log an inode even if a log commit has already taken place. In order to
make sure we didn't relog the same inode multiple times he set this local copy
to the current trans when we log the inode, because usually we log the inode and
then sync the log. The exception to this is during rename, we will relog an
inode if the name changed and it is already in the log. The problem with this
is then we go to sync the inode, and our check to see if the inode has already
been logged is tripped and we don't sync the log. To fix this we need to _also_
check against the roots last log commit, because it could be less than what is
in our local copy of the log commit. This fixes a bug where we rename a file
into a directory and then fsync the directory and then on remount the directory
is no longer there. Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

show more ...

Btrfs: don't cache the csum value into the extent state tree

Before applying this patch, we cached the csum value into the extent state
tree when reading some data from the disk, this operation incr

Btrfs: don't cache the csum value into the extent state tree

Before applying this patch, we cached the csum value into the extent state
tree when reading some data from the disk, this operation increased the lock
contention of the state tree.

Now, we just store the csum value into the bio structure or other unshared
structure, so we can reduce the lock contention.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

show more ...

btrfs: fix minor typo in comment

In the comment describing the sync_writers field of the btrfs_inode
struct, "fsyncing" was misspelled "fsycing."

Signed-off-by: Nathaniel Yazdani <n1ght.4nd.d4y@gma

btrfs: fix minor typo in comment

In the comment describing the sync_writers field of the btrfs_inode
struct, "fsyncing" was misspelled "fsycing."

Signed-off-by: Nathaniel Yazdani <n1ght.4nd.d4y@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

show more ...

Btrfs: serialize unlocked dio reads with truncate

Currently, we can do unlocked dio reads, but the following race
is possible:

dio_read_task truncate_task
->btrfs_setattr()
->btrfs_direct_IO

Btrfs: serialize unlocked dio reads with truncate

Currently, we can do unlocked dio reads, but the following race
is possible:

dio_read_task truncate_task
->btrfs_setattr()
->btrfs_direct_IO
->__blockdev_direct_IO
->btrfs_get_block
->btrfs_truncate()
#alloc truncated blocks
#to other inode
->submit_io()
#INFORMATION LEAK

In order to avoid this problem, we must serialize unlocked dio reads with
truncate. There are two approaches:
- use extent lock to protect the extent that we truncate
- use inode_dio_wait() to make sure the truncating task will wait for
the read DIO.

If we use the 1st one, we will meet the endless truncation problem due to
the nonlocked read DIO after we implement the nonlocked write DIO. It is
because we still need invoke inode_dio_wait() avoid the race between write
DIO and truncation. By that time, we have to introduce

btrfs_inode_{block, resume}_nolock_dio()

again. That is we have to implement this patch again, so I choose the 2nd
way to fix the problem.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

show more ...

Btrfs: use the inode own lock to protect its delalloc_bytes

We need not use a global lock to protect the delalloc_bytes of the
inode, just use its own lock. In this way, we can reduce the lock
conte

Btrfs: use the inode own lock to protect its delalloc_bytes

We need not use a global lock to protect the delalloc_bytes of the
inode, just use its own lock. In this way, we can reduce the lock
contention and ->delalloc_lock will just protect delalloc inode
list.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

show more ...

Btrfs: inline csums if we're fsyncing

The tree logging stuff needs the csums to be on the ordered extents in order
to log them properly, so mark that we're sync and inline the csum creation
so we do

Btrfs: inline csums if we're fsyncing

The tree logging stuff needs the csums to be on the ordered extents in order
to log them properly, so mark that we're sync and inline the csum creation
so we don't have to wait on the csumming to be done when logging extents
that are still in flight. Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

show more ...

Btrfs: only log the inode item if we can get away with it

Currently we copy all the file information into the log, inode item, the
refs, xattrs etc. Except most of this doesn't change from fsync to

Btrfs: only log the inode item if we can get away with it

Currently we copy all the file information into the log, inode item, the
refs, xattrs etc. Except most of this doesn't change from fsync to fsync,
just the inode item changes. So set a flag if an xattr changes or a link is
added, and otherwise only log the inode item. Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

show more ...

Btrfs: fix a bug in checking whether a inode is already in log

This is based on Josef's "Btrfs: turbo charge fsync".

The current btrfs checks if an inode is in log by comparing
root's last_log_comm

Btrfs: fix a bug in checking whether a inode is already in log

This is based on Josef's "Btrfs: turbo charge fsync".

The current btrfs checks if an inode is in log by comparing
root's last_log_commit to inode's last_sub_trans[2].

But the problem is that this root->last_log_commit is shared among
inodes.

Say we have N inodes to be logged, after the first inode,
root's last_log_commit is updated and the N-1 remained files will
be skipped.

This fixes the bug by keeping a local copy of root's last_log_commit
inside each inode and this local copy will be maintained itself.

[1]: we regard each log transaction as a subset of btrfs's transaction,
i.e. sub_trans

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>

show more ...

Btrfs: turbo charge fsync

At least for the vm workload. Currently on fsync we will

1) Truncate all items in the log tree for the given inode if they exist

and

2) Copy all items for a given inode

Btrfs: turbo charge fsync

At least for the vm workload. Currently on fsync we will

1) Truncate all items in the log tree for the given inode if they exist

and

2) Copy all items for a given inode into the log

The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing. This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them. We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already. Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write

Original Patched
SATA drive 82KB/s 140KB/s
Fusion drive 431KB/s 2532KB/s

So around 2-6 times faster depending on your hardware. There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok. This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get. All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.

The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok. I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>

show more ...