Commit Graph

4162 Commits

Author SHA1 Message Date
Gerhard Heift 25c9bc2e2b btrfs: tree_search: eliminate redundant nr_items check
If the amount of items reached the given limit of nr_items, we can leave
copy_to_sk without updating the key. Also by returning 1 we leave the loop in
search_ioctl without rechecking if we reached the given limit.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:20:39 -07:00
Linus Torvalds 16b9057804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...
2014-06-12 10:30:18 -07:00
Al Viro 9c1d5284c7 Merge commit '9f12600fe425bc28f0ccba034a77783c09c15af4' into for-linus
Backmerge of dcache.c changes from mainline.  It's that, or complete
rebase...

Conflicts:
	fs/splice.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-12 00:28:09 -04:00
Linus Torvalds 859862ddd2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "The biggest change here is Josef's rework of the btrfs quota
  accounting, which improves the in-memory tracking of delayed extent
  operations.

  I had been working on Btrfs stack usage for a while, mostly because it
  had become impossible to do long stress runs with slab, lockdep and
  pagealloc debugging turned on without blowing the stack.  Even though
  you upgraded us to a nice king sized stack, I kept most of the
  patches.

  We also have some very hard to find corruption fixes, an awesome sysfs
  use after free, and the usual assortment of optimizations, cleanups
  and other fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (80 commits)
  Btrfs: convert smp_mb__{before,after}_clear_bit
  Btrfs: fix scrub_print_warning to handle skinny metadata extents
  Btrfs: make fsync work after cloning into a file
  Btrfs: use right type to get real comparison
  Btrfs: don't check nodes for extent items
  Btrfs: don't release invalid page in btrfs_page_exists_in_range()
  Btrfs: make sure we retry if page is a retriable exception
  Btrfs: make sure we retry if we couldn't get the page
  btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56
  trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/
  Btrfs: fix leaf corruption after __btrfs_drop_extents
  Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item
  Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled
  btrfs: free delayed node outside of root->inode_lock
  btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAX
  Btrfs: fix transaction leak during fsync call
  btrfs: Avoid trucating page or punching hole in a already existed hole.
  Btrfs: update commit root on snapshot creation after orphan cleanup
  Btrfs: ioctl, don't re-lock extent range when not necessary
  Btrfs: avoid visiting all extent items when cloning a range
  ...
2014-06-11 09:22:21 -07:00
Chris Mason c7548af69d Btrfs: convert smp_mb__{before,after}_clear_bit
The new call is smp_mb__{before,after}_atomic.  The __ gives us extra
protection from the atomic rays.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10 13:10:47 -07:00
Liu Bo 6eda71d0c0 Btrfs: fix scrub_print_warning to handle skinny metadata extents
The skinny extents are intepreted incorrectly in scrub_print_warning(),
and end up hitting the BUG() in btrfs_extent_inline_ref_size.

Reported-by: Konstantinos Skarlatos <k.skarlatos@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:17 -07:00
Filipe Manana 7ffbb598a0 Btrfs: make fsync work after cloning into a file
When cloning into a file, we were correctly replacing the extent
items in the target range and removing the extent maps. However
we weren't replacing the extent maps with new ones that point to
the new extents - as a consequence, an incremental fsync (when the
inode doesn't have the full sync flag) was a NOOP, since it relies
on the existence of extent maps in the modified list of the inode's
extent map tree, which was empty. Therefore add new extent maps to
reflect the target clone range.

A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:16 -07:00
Liu Bo cd857dd6bc Btrfs: use right type to get real comparison
We want to make sure the point is still within the extent item, not to verify
the memory it's pointing to.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:15 -07:00
Josef Bacik 8a56457f5f Btrfs: don't check nodes for extent items
The backref code was looking at nodes as well as leaves when we tried to
populate extent item entries.  This is not good, and although we go away with it
for the most part because we'd skip where disk_bytenr != random_memory,
sometimes random_memory would match and suddenly boom.  This fixes that problem.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:14 -07:00
Filipe Manana 6fdef6d43c Btrfs: don't release invalid page in btrfs_page_exists_in_range()
In inode.c:btrfs_page_exists_in_range(), if the page we got from
the radix tree is an exception entry, which can't be retried, we
exit the loop with a non-NULL page and then call page_cache_release
against it, which is not ok since it's not a valid page. This could
also make us return true when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:14 -07:00
Filipe Manana 809f901625 Btrfs: make sure we retry if page is a retriable exception
In inode.c:btrfs_page_exists_in_range(), if the page we get from the
radix tree is an exception which should make us retry, set page to
NULL in order to really retry, because otherwise we don't get another
loop iteration executed (page != NULL makes the while loop exit).
This also was making us call page_cache_release after exiting the loop,
which isn't correct because page doesn't point to a valid page, and
possibly return true from the function when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:13 -07:00
Filipe Manana 91405151eb Btrfs: make sure we retry if we couldn't get the page
In inode.c:btrfs_page_exists_in_range(), if we can't get the page
we need to retry. However we weren't retrying because we weren't
setting page to NULL, which makes the while loop exit immediately
and will make us call page_cache_release after exiting the loop
which is incorrect because our page get didn't succeed. This could
also make us return true when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:12 -07:00
Gui Hecheng c81d57679e btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56
To return EOPNOTSUPP is more user friendly than to return EINVAL,
and then user-space tool will show that the dev_replace operation
for raid56 is not currently supported rather than showing that
there is an invalid argument.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:12 -07:00
Antonio Ospite 9391558411 trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/
Signed-off-by: Antonio Ospite <ao2@ao2.it>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:11 -07:00
Liu Bo 0b43e04f70 Btrfs: fix leaf corruption after __btrfs_drop_extents
Several reports about leaf corruption has been floating on the list, one of them
points to __btrfs_drop_extents(), and we find that the leaf becomes corrupted
after __btrfs_drop_extents(), it's really a rare case but it does exist.

The problem turns out to be btrfs_next_leaf() called in __btrfs_drop_extents().

So in btrfs_next_leaf(), we release the current path to re-search the last key of
the leaf for locating next leaf, and we've taken it into account that there might
be balance operations between leafs during this 'unlock and re-lock' dance, so
we check the path again and advance it if there are now more items available.
But things are a bit different if that last key happens to be removed and balance
gets a bigger key as the last one, and btrfs_search_slot will return it with
ret > 0, IOW, nothing change in this leaf except the new last key, then we think
we're okay because there is no more item balanced in, fine, we thinks we can
go to the next leaf.

However, we should return that bigger key, otherwise we deserve leaf corruption,
for example, in endio, skipping that key means that __btrfs_drop_extents() thinks
it has dropped all extent matched the required range and finish_ordered_io can
safely insert a new extent, but it actually doesn't and ends up a leaf
corruption.

One may be asking that why our locking on extent io tree doesn't work as
expected, ie. it should avoid this kind of race situation.  But in
__btrfs_drop_extents(), we don't always find extents which are included within
our locking range, IOW, extents can start before our searching start, in this
case locking on extent io tree doesn't protect us from the race.

This takes the special case into account.

Reviewed-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:10 -07:00
Filipe Manana 337c6f6830 Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item
We might have had an item with the previous key in the tree right
before we released our path. And after we released our path, that
item might have been pushed to the first slot (0) of the leaf we
were holding due to a tree balance. Alternatively, an item with the
previous key can exist as the only element of a leaf (big fat item).
Therefore account for these 2 cases, so that our callers (like
btrfs_previous_item) don't miss an existing item with a key matching
the previous key we computed above.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:09 -07:00
Filipe Manana f82a9901b0 Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled
If the NO_HOLES feature is enabled holes don't have file extent items in
the btree that represent them anymore. This made the clone operation
ignore the gaps that exist between consecutive file extent items and
therefore not create the holes at the destination. When not using the
NO_HOLES feature, the holes were created at the destination.

A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:09 -07:00
Jeff Mahoney 964930312a btrfs: free delayed node outside of root->inode_lock
On heavy workloads, we're seeing soft lockup warnings on
root->inode_lock in __btrfs_release_delayed_node. The low hanging fruit
is to reduce the size of the critical section.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:08 -07:00
Gui Hecheng 902c68a4da btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAX
To be accurate about the error case,
if the new size is beyond ULLONG_MAX, return ERANGE instead of EINVAL.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:07 -07:00
Filipe Manana b05fd8742f Btrfs: fix transaction leak during fsync call
If btrfs_log_dentry_safe() returns an error, we set ret to 1 and
fall through with the goal of committing the transaction. However,
in the case where the inode doesn't need a full sync, we would call
btrfs_wait_ordered_range() against the target range for our inode,
and if it returned an error, we would return without commiting or
ending the transaction.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:06 -07:00
Qu Wenruo d77815461f btrfs: Avoid trucating page or punching hole in a already existed hole.
btrfs_punch_hole() will truncate unaligned pages or punch hole on a
already existed hole.
This will cause unneeded zero page or holes splitting the original huge
hole.

This patch will skip already existed holes before any page truncating or
hole punching.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:06 -07:00
Filipe Manana 3821f34888 Btrfs: update commit root on snapshot creation after orphan cleanup
On snapshot creation (either writable or read-only), we do orphan cleanup
against the root of the snapshot. If the cleanup did remove any orphans,
then the current root node will be different from the commit root node
until the next transaction commit happens.

A send operation always uses the commit root of a snapshot - this means
it will see the orphans if it starts computing the send stream before the
next transaction commit happens (triggered by a timer or sync() for .e.g),
which is when the commit root gets assigned a reference to current root,
where the orphans are not visible anymore. The consequence of send seeing
the orphans is explained below.

For example:

    mkfs.btrfs -f /dev/sdd
    mount -o commit=999 /dev/sdd /mnt

    # open a file with O_TMPFILE and leave it open
    # write some data to the file
    btrfs subvolume snapshot -r /mnt /mnt/snap1

    btrfs send /mnt/snap1 -f /tmp/send.data

The send operation will fail with the following error:

    ERROR: send ioctl failed with -116: Stale file handle

What happens here is that our snapshot has an orphan inode still visible
through the commit root, that corresponds to the tmpfile. However send
will attempt to call inode.c:btrfs_iget(), with the goal of reading the
file's data, which will return -ESTALE because it will use the current
root (and not the commit root) of the snapshot.

Of course, there are other cases where we can get orphans, but this
example using a tmpfile makes it much easier to reproduce the issue.

Therefore on snapshot creation, after calling btrfs_orphan_cleanup, if
the commit root is different from the current root, just commit the
transaction associated with the snapshot's root (if it exists), so that
a send will not see any orphans that don't exist anymore. This also
guarantees a send will always see the same content regardless of whether
a transaction commit happened already before the send was requested and
after the orphan cleanup (meaning the commit root and current roots are
the same) or it hasn't happened yet (commit and current roots are
different).

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:05 -07:00
Filipe Manana ff5df9b884 Btrfs: ioctl, don't re-lock extent range when not necessary
In ioctl.c:lock_extent_range(), after locking our target range, the
ordered extent that btrfs_lookup_first_ordered_extent() returns us
may not overlap our target range at all. In this case we would just
unlock our target range, wait for any new ordered extents that overlap
the range to complete, lock again the range and repeat all these steps
until we don't get any ordered extent and the delalloc flag isn't set
in the io tree for our target range.

Therefore just stop if we get an ordered extent that doesn't overlap
our target range and the dealalloc flag isn't set for the range in
the inode's io tree.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:04 -07:00
Filipe Manana 2c463823cb Btrfs: avoid visiting all extent items when cloning a range
When cloning a range of a file, we were visiting all the extent items in
the btree that belong to our source inode. We don't need to visit those
extent items that don't overlap the range we are cloning, as doing so only
makes us waste time and do unnecessary btree navigations (btrfs_next_leaf)
for inodes that have a large number of file extent items in the btree.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:04 -07:00
Filipe Manana c55bfa67e9 Btrfs: set dead flag on the right root when destroying snapshot
We were setting the BTRFS_ROOT_SUBVOL_DEAD flag on the root of the
parent of our target snapshot, instead of setting it in the target
snapshot's root.

This is easy to observe by running the following scenario:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    btrfs subvolume create /mnt/first_subvol
    btrfs subvolume snapshot -r /mnt /mnt/mysnap1

    btrfs subvolume delete /mnt/first_subvol
    btrfs subvolume snapshot -r /mnt /mnt/mysnap2

    btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data

The send command failed because the send ioctl returned -EPERM.
A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:03 -07:00
Filipe Manana c125b8bff1 Btrfs: ensure readers see new data after a clone operation
We were cleaning the clone target file range from the page cache before
we did replace the file extent items in the fs tree. This was racy,
as right after cleaning the relevant range from the page cache and before
replacing the file extent items, a read against that range could be
performed by another task and populate again the page cache with stale
data (stale after the cloning finishes). This would result in reads after
the clone operation successfully finishes to get old data (and potentially
for a very long time). Therefore evict the pages after replacing the file
extent items, so that subsequent reads will always get the new data.

Similarly, we were prone to races while cloning the file extent items
because we weren't locking the target range and wait for any existing
ordered extents against that range to complete. It was possible that
after cloning the extent items, a write operation that was performed
before the clone operation and overlaps the same range, would end up
undoing all or part of the work the clone operation did (a worker task
running inode.c:btrfs_finish_ordered_io). Therefore lock the target
range in the io tree, wait for all pending ordered extents against that
range to finish and then safely perform the cloning.

The issue of reading stale data after the clone operation is easy to
reproduce by running the following C program in a loop until it exits
with return value 1.

 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 #include <pthread.h>
 #include <fcntl.h>
 #include <assert.h>
 #include <asm/types.h>
 #include <linux/ioctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>

 #define SRC_FILE "/mnt/sdd/foo"
 #define DST_FILE "/mnt/sdd/bar"
 #define FILE_SIZE (16 * 1024)
 #define PATTERN_SRC 'X'
 #define PATTERN_DST 'Y'

struct btrfs_ioctl_clone_range_args {
	__s64 src_fd;
	__u64 src_offset, src_length;
	__u64 dest_offset;
};

 #define BTRFS_IOCTL_MAGIC 0x94
 #define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
				   struct btrfs_ioctl_clone_range_args)

static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static int clone_done = 0;
static int reader_ready = 0;
static int stale_data = 0;

static void *reader_loop(void *arg)
{
	char buf[4096], want_buf[4096];

	memset(want_buf, PATTERN_SRC, 4096);
	pthread_mutex_lock(&mutex);
	reader_ready = 1;
	pthread_mutex_unlock(&mutex);

	while (1) {
		int done, fd, ret;

		fd = open(DST_FILE, O_RDONLY);
		assert(fd != -1);

		pthread_mutex_lock(&mutex);
		done = clone_done;
		pthread_mutex_unlock(&mutex);

		ret = read(fd, buf, 4096);
		assert(ret == 4096);
		close(fd);

		if (done) {
			ret = memcmp(buf, want_buf, 4096);
			if (ret == 0) {
				printf("Found new content\n");
			} else {
				printf("Found old content\n");
				pthread_mutex_lock(&mutex);
				stale_data = 1;
				pthread_mutex_unlock(&mutex);
			}
			break;
		}
	}
	return NULL;
}

int main(int argc, char *argv[])
{
	pthread_t reader;
	int ret, i, fd;
	struct btrfs_ioctl_clone_range_args clone_args;
	int fd1, fd2;

	ret = remove(SRC_FILE);
	if (ret == -1 && errno != ENOENT) {
		fprintf(stderr, "Error deleting src file: %s\n", strerror(errno));
		return 1;
	}
	ret = remove(DST_FILE);
	if (ret == -1 && errno != ENOENT) {
		fprintf(stderr, "Error deleting dst file: %s\n", strerror(errno));
		return 1;
	}

	fd = open(SRC_FILE, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU);
	assert(fd != -1);
	for (i = 0; i < FILE_SIZE; i++) {
		char c = PATTERN_SRC;
		ret = write(fd, &c, 1);
		assert(ret == 1);
	}
	close(fd);
	fd = open(DST_FILE, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU);
	assert(fd != -1);
	for (i = 0; i < FILE_SIZE; i++) {
		char c = PATTERN_DST;
		ret = write(fd, &c, 1);
		assert(ret == 1);
	}
	close(fd);
        sync();

	ret = pthread_create(&reader, NULL, reader_loop, NULL);
	assert(ret == 0);
	while (1) {
		int r;
		pthread_mutex_lock(&mutex);
		r = reader_ready;
		pthread_mutex_unlock(&mutex);
		if (r) break;
	}

	fd1 = open(SRC_FILE, O_RDONLY);
	if (fd1 < 0) {
		fprintf(stderr, "Error open src file: %s\n", strerror(errno));
		return 1;
	}
	fd2 = open(DST_FILE, O_RDWR);
	if (fd2 < 0) {
		fprintf(stderr, "Error open dst file: %s\n", strerror(errno));
		return 1;
	}
	clone_args.src_fd = fd1;
	clone_args.src_offset = 0;
	clone_args.src_length = 4096;
	clone_args.dest_offset = 0;
	ret = ioctl(fd2, BTRFS_IOC_CLONE_RANGE, &clone_args);
	assert(ret == 0);
	close(fd1);
	close(fd2);

	pthread_mutex_lock(&mutex);
	clone_done = 1;
	pthread_mutex_unlock(&mutex);
	ret = pthread_join(reader, NULL);
	assert(ret == 0);

	pthread_mutex_lock(&mutex);
	ret = stale_data ? 1 : 0;
	pthread_mutex_unlock(&mutex);
	return ret;
}

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:02 -07:00
Rickard Strandqvist 8321cf2596 fs: btrfs: volumes.c: Fix for possible null pointer dereference
There is otherwise a risk of a possible null pointer dereference.

Was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:01 -07:00
Jeff Mahoney c1895442be btrfs: allocate raid type kobjects dynamically
We are currently allocating space_info objects in an array when we
allocate space_info. When a user does something like:

# btrfs balance start -mconvert=raid1 -dconvert=raid1 /mnt
# btrfs balance start -mconvert=single -dconvert=single /mnt -f
# btrfs balance start -mconvert=raid1 -dconvert=raid1 /

We can end up with memory corruption since the kobject hasn't
been reinitialized properly and the name pointer was left set.

The rationale behind allocating them statically was to avoid
creating a separate kobject container that just contained the
raid type. It used the index in the array to determine the index.

Ultimately, though, this wastes more memory than it saves in all
but the most complex scenarios and introduces kobject lifetime
questions.

This patch allocates the kobjects dynamically instead. Note that
we also remove the kobject_get/put of the parent kobject since
kobject_add and kobject_del do that internally.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:01 -07:00
Filipe Manana 7e3ae33efa Btrfs: send, use the right limits for xattr names and values
We were limiting the sum of the xattr name and value lengths to PATH_MAX,
which is not correct, specially on filesystems created with btrfs-progs
v3.12 or higher, where the default leaf size is max(16384, PAGE_SIZE), or
systems with page sizes larger than 4096 bytes.

Xattrs have their own specific maximum name and value lengths, which depend
on the leaf size, therefore use these limits to be able to send xattrs with
sizes larger than PATH_MAX.

A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:00 -07:00
Filipe Manana 1af56070e3 Btrfs: send, don't error in the presence of subvols/snapshots
If we are doing an incremental send and the base snapshot has a
directory with name X that doesn't exist anymore in the second
snapshot and a new subvolume/snapshot exists in the second snapshot
that has the same name as the directory (name X), the incremental
send would fail with -ENOENT error. This is because it attempts
to lookup for an inode with a number matching the objectid of a
root, which doesn't exist.

Steps to reproduce:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    mkdir /mnt/testdir
    btrfs subvolume snapshot -r /mnt /mnt/mysnap1

    rmdir /mnt/testdir
    btrfs subvolume create /mnt/testdir
    btrfs subvolume snapshot -r /mnt /mnt/mysnap2

    btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data

A test case for xfstests follows.

Reported-by: Robert White <rwhite@pobox.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:59 -07:00
Chris Mason a79b7d4b3e Btrfs: async delayed refs
Delayed extent operations are triggered during transaction commits.
The goal is to queue up a healthly batch of changes to the extent
allocation tree and run through them in bulk.

This farms them off to async helper threads.  The goal is to have the
bulk of the delayed operations being done in the background, but this is
also important to limit our stack footprint.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:58 -07:00
Chris Mason 40f765805f Btrfs: split up __extent_writepage to lower stack usage
__extent_writepage has two unrelated parts.  First it does the delayed
allocation dance and second it does the mapping and IO for the page
we're actually writing.

This splits it up into those two parts so the stack from one doesn't
impact the stack from the other.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:58 -07:00
Alex Gartrell fc4adbff82 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>
2014-06-09 17:20:57 -07:00
Chris Mason 0e378df15c Btrfs: cut down stack usage in btree_write_cache_pages
This adds noinline_for_stack to two helpers used by
btree_write_cache_pages.  It shaves us down from 424 bytes on the
stack to 280.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:56 -07:00
Chris Mason d4452bc526 Btrfs: break up __btrfs_write_out_cache to cut down stack usage
__btrfs_write_out_cache was one of our stack pigs.  This breaks it
up into helper functions and slims it down to 194 bytes.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:55 -07:00
Josef Bacik 2a10840945 Btrfs: free tmp ulist for qgroup rescan
Memory leaks are bad mmkay?

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:55 -07:00
Anand Jain 402a0f4759 btrfs: usage error should not be logged into system log
I have an opinion that system logs /var/log/messages are
valuable info to investigate the real system issues at
the data center. People handling data center issues
do spend a lot time and efforts analyzing messages
files. Having usage error logged into /var/log/messages
is something we should avoid.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:54 -07:00
David Sterba 67a77eb147 btrfs: remove newline from inode cache kthread name
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:53 -07:00
David Sterba 351fd35321 btrfs: remove stale newlines from log messages
I've noticed an extra line after "use no compression", but search
revealed much more in messages of more critical levels and rare errors.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:53 -07:00
Chris Mason 7d78874273 Btrfs: fix double free in find_lock_delalloc_range
We need to NULL the cached_state after freeing it, otherwise
we might free it again if find_delalloc_range doesn't find anything.

Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org
2014-06-09 17:20:52 -07:00
ZhangZhen 58dfae6365 btrfs: replace simple_strtoull() with kstrtoull()
use the newer and more pleasant kstrtoull() to replace simple_strtoull(),
because simple_strtoull() is marked for obsoletion.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:51 -07:00
Wang Shilong 298658414a Btrfs: set right total device count for seeding support
Seeding device support allows us to create a new filesystem
based on existed filesystem.

However newly created filesystem's @total_devices should include seed
devices. This patch fix the following problem:

 # mkfs.btrfs -f /dev/sdb
 # btrfstune -S 1 /dev/sdb
 # mount /dev/sdb /mnt
 # btrfs device add -f /dev/sdc /mnt --->fs_devices->total_devices = 1
 # umount /mnt
 # mount /dev/sdc /mnt               --->fs_devices->total_devices = 2

This is because we record right @total_devices in superblock, but
@fs_devices->total_devices is reset to be 0 in btrfs_prepare_sprout().

Fix this problem by not resetting @fs_devices->total_devices.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:50 -07:00
Guangliang Zhao 45ff35d6b9 Btrfs: remove OPT_acl parse when acl disabled
Even CONFIG_BTRFS_FS_POSIX_ACL is not defined, the acl still could
been enabled using a mount option, and now fs/btrfs/acl.o is not
built, so the mount options will appear to be supported but will
be silently ignored.

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:50 -07:00
Josef Bacik faa2dbf004 Btrfs: add sanity tests for new qgroup accounting code
This exercises the various parts of the new qgroup accounting code.  We do some
basic stuff and do some things with the shared refs to make sure all that code
works.  I had to add a bunch of infrastructure because I needed to be able to
insert items into a fake tree without having to do all the hard work myself,
hopefully this will be usefull in the future.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:49 -07:00
Josef Bacik fcebe4562d Btrfs: rework qgroup accounting
Currently qgroups account for space by intercepting delayed ref updates to fs
trees.  It does this by adding sequence numbers to delayed ref updates so that
it can figure out how the tree looked before the update so we can adjust the
counters properly.  The problem with this is that it does not allow delayed refs
to be merged, so if you say are defragging an extent with 5k snapshots pointing
to it we will thrash the delayed ref lock because we need to go back and
manually merge these things together.  Instead we want to process quota changes
when we know they are going to happen, like when we first allocate an extent, we
free a reference for an extent, we add new references etc.  This patch
accomplishes this by only adding qgroup operations for real ref changes.  We
only modify the sequence number when we need to lookup roots for bytenrs, this
reduces the amount of churn on the sequence number and allows us to merge
delayed refs as we add them most of the time.  This patch encompasses a bunch of
architectural changes

1) qgroup ref operations: instead of tracking qgroup operations through the
delayed refs we simply add new ref operations whenever we notice that we need to
when we've modified the refs themselves.

2) tree mod seq:  we no longer have this separation of major/minor counters.
this makes the sequence number stuff much more sane and we can remove some
locking that was needed to protect the counter.

3) delayed ref seq: we now read the tree mod seq number and use that as our
sequence.  This means each new delayed ref doesn't have it's own unique sequence
number, rather whenever we go to lookup backrefs we inc the sequence number so
we can make sure to keep any new operations from screwing up our world view at
that given point.  This allows us to merge delayed refs during runtime.

With all of these changes the delayed ref stuff is a little saner and the qgroup
accounting stuff no longer goes negative in some cases like it was before.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:48 -07:00
Liu Bo 5dca6eea91 Btrfs: mark mapping with error flag to report errors to userspace
According to commit 865ffef379
(fs: fix fsync() error reporting),
it's not stable to just check error pages because pages can be
truncated or invalidated, we should also mark mapping with error
flag so that a later fsync can catch the error.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:47 -07:00
Liu Bo 29cc83f69c Btrfs: fix NULL pointer crash of deleting a seed device
Same as normal devices, seed devices should be initialized with
fs_info->dev_root as well, otherwise we'll get a NULL pointer crash.

Cc: Chris Murphy <lists@colorremedies.com>
Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:47 -07:00
Wang Shilong f017f15f7c Btrfs: fix joining same transaction handle more than twice
We hit something like the following function call flows:

|->run_delalloc_range()
 |->btrfs_join_transaction()
   |->cow_file_range()
     |->btrfs_join_transaction()
       |->find_free_extent()
         |->btrfs_join_transaction()

Trace infomation can be seen as:

[ 7411.127040] ------------[ cut here ]------------
[ 7411.127060] WARNING: CPU: 0 PID: 11557 at fs/btrfs/transaction.c:383 start_transaction+0x561/0x580 [btrfs]()
[ 7411.127079] CPU: 0 PID: 11557 Comm: kworker/u8:9 Tainted: G           O 3.13.0+ #4
[ 7411.127080] Hardware name: LENOVO QiTianM4350/ , BIOS F1KT52AUS 05/24/2013
[ 7411.127085] Workqueue: writeback bdi_writeback_workfn (flush-btrfs-5)
[ 7411.127092] Call Trace:
[ 7411.127097]  [<ffffffff815b87b0>] dump_stack+0x45/0x56
[ 7411.127101]  [<ffffffff81051ffd>] warn_slowpath_common+0x7d/0xa0
[ 7411.127102]  [<ffffffff810520da>] warn_slowpath_null+0x1a/0x20
[ 7411.127109]  [<ffffffffa0444fb1>] start_transaction+0x561/0x580 [btrfs]
[ 7411.127115]  [<ffffffffa0445027>] btrfs_join_transaction+0x17/0x20 [btrfs]
[ 7411.127120]  [<ffffffffa0431c91>] find_free_extent+0xa21/0xb50 [btrfs]
[ 7411.127126]  [<ffffffffa0431f68>] btrfs_reserve_extent+0xa8/0x1a0 [btrfs]
[ 7411.127131]  [<ffffffffa04322ce>] btrfs_alloc_free_block+0xee/0x440 [btrfs]
[ 7411.127137]  [<ffffffffa043bd6e>] ? btree_set_page_dirty+0xe/0x10 [btrfs]
[ 7411.127142]  [<ffffffffa041da51>] __btrfs_cow_block+0x121/0x530 [btrfs]
[ 7411.127146]  [<ffffffffa041dfff>] btrfs_cow_block+0x11f/0x1c0 [btrfs]
[ 7411.127151]  [<ffffffffa0421b74>] btrfs_search_slot+0x1d4/0x9c0 [btrfs]
[ 7411.127157]  [<ffffffffa0438567>] btrfs_lookup_file_extent+0x37/0x40 [btrfs]
[ 7411.127163]  [<ffffffffa0456bfc>] __btrfs_drop_extents+0x16c/0xd90 [btrfs]
[ 7411.127169]  [<ffffffffa0444ae3>] ? start_transaction+0x93/0x580 [btrfs]
[ 7411.127171]  [<ffffffff811663e2>] ? kmem_cache_alloc+0x132/0x140
[ 7411.127176]  [<ffffffffa041cd9a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[ 7411.127182]  [<ffffffffa044aa61>] cow_file_range_inline+0x181/0x2e0 [btrfs]
[ 7411.127187]  [<ffffffffa044aead>] cow_file_range+0x2ed/0x440 [btrfs]
[ 7411.127194]  [<ffffffffa0464d7f>] ? free_extent_buffer+0x4f/0xb0 [btrfs]
[ 7411.127200]  [<ffffffffa044b38f>] run_delalloc_nocow+0x38f/0xa60 [btrfs]
[ 7411.127207]  [<ffffffffa0461600>] ? test_range_bit+0x30/0x180 [btrfs]
[ 7411.127212]  [<ffffffffa044bd48>] run_delalloc_range+0x2e8/0x350 [btrfs]
[ 7411.127219]  [<ffffffffa04618f9>] ? find_lock_delalloc_range+0x1a9/0x1e0 [btrfs]
[ 7411.127222]  [<ffffffff812a1e71>] ? blk_queue_bio+0x2c1/0x330
[ 7411.127228]  [<ffffffffa0462ad4>] __extent_writepage+0x2f4/0x760 [btrfs]

Here we fix it by avoiding joining transaction again if we have held
a transaction handle when allocating chunk in find_free_extent().

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:46 -07:00
Miao Xie 995946dd29 Btrfs: use helpers for last_trans_log_full_commit instead of opencode
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:45 -07:00
Filipe Manana 1f21ef0a34 Btrfs: check if items are ordered when a leaf is marked dirty
To ease finding bugs during development related to modifying btree leaves
in such a way that it makes its items not sorted by key anymore. Since this
is an expensive check, it's only enabled if CONFIG_BTRFS_FS_CHECK_INTEGRITY
is set, which isn't meant to be enabled for regular users.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:45 -07:00
Filipe Manana 35045bf2fd Btrfs: don't access non-existent key when csum tree is empty
When the csum tree is empty, our leaf (path->nodes[0]) has a number
of items equal to 0 and since btrfs_header_nritems() returns an
unsigned integer (and so is our local nritems variable) the following
comparison always evaluates to false:

     if (path->slots[0] >= nritems - 1) {

As the casting rules lead to:

     if ((u32)0 >= (u32)4294967295) {

This makes us access key at slot paths->slots[0] + 1 (1) of the empty leaf
some lines below:

    btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
    if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
        found_key.type != BTRFS_EXTENT_CSUM_KEY) {
		found_next = 1;
		goto insert;
    }

So just don't access such non-existent slot and don't set found_next to 1
when the tree is empty. It's very unlikely we'll get a random key with the
objectid and type values above, which is where we could go into trouble.

If nritems is 0, just set found_next to 1 anyway as it will make us insert
a csum item covering our whole extent (or the whole leaf) when the tree is
empty.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:44 -07:00
Wang Shilong de348ee022 Btrfs: make sure there are not any read requests before stopping workers
In close_ctree(), after we have stopped all workers,there maybe still
some read requests(for example readahead) to submit and this *maybe* trigger
an oops that user reported before:

kernel BUG at fs/btrfs/async-thread.c:619!

By hacking codes, i can reproduce this problem with one cpu available.
We fix this potential problem by invalidating all btree inode pages before
stopping all workers.

Thanks to Miao for pointing out this problem.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:43 -07:00
Tsutomu Itoh 59885b3930 Btrfs: fix possible memory leak in btrfs_create_tree()
In btrfs_create_tree(), if btrfs_insert_root() fails, we should
free root->commit_root.

Reported-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:42 -07:00
ZhangZhen 776e4aae55 btrfs: remove useless ACL check
posix_acl_xattr_set() already does the check, and it's the only
way to feed in an ACL from userspace.
So the check here is useless, remove it.

Signed-off-by: zhang zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:42 -07:00
Anand Jain 4d90d28b1c btrfs: btrfs_rm_device() should zero mirror SB as well
This fix will ensure all SB copies on the disk is zeroed
when the disk is intentionally removed. This helps to
better manage disks in the user land.

This version of patch also merges the Zach patch as below.

 btrfs: don't double brelse on device rm

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:41 -07:00
Miao Xie 27cdeb7096 Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:40 -07:00
Filipe Manana f959492fc1 Btrfs: send, fix more issues related to directory renames
This is a continuation of the previous changes titled:

   Btrfs: fix incremental send's decision to delay a dir move/rename
   Btrfs: part 2, fix incremental send's decision to delay a dir move/rename

There's a few more cases where a directory rename/move must be delayed which was
previously overlooked. If our immediate ancestor has a lower inode number than
ours and it doesn't have a delayed rename/move operation associated to it, it
doesn't mean there isn't any non-direct ancestor of our current inode that needs
to be renamed/moved before our current inode (i.e. with a higher inode number
than ours).

So we can't stop the search if our immediate ancestor has a lower inode number than
ours, we need to navigate the directory hierarchy upwards until we hit the root or:

1) find an ancestor with an higher inode number that was renamed/moved in the send
   root too (or already has a pending rename/move registered);
2) find an ancestor that is a new directory (higher inode number than ours and
   exists only in the send root).

Reproducer for case 1)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir -p /mnt/a/c/d
    $ mkdir /mnt/a/b/e
    $ mkdir /mnt/a/c/d/f
    $ mv /mnt/a/b /mnt/a/c/d/2b
    $ mkdir /mnt/a/x
    $ mkdir /mnt/a/y

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mv /mnt/a/x /mnt/a/y
    $ mv /mnt/a/c/d/2b/e /mnt/a/c/d/2b/2e
    $ mv /mnt/a/c/d /mnt/a/h/2d
    $ mv /mnt/a/c /mnt/a/h/2d/2b/2c

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

Simple reproducer for case 2)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir /mnt/a/c
    $ mv /mnt/a/b /mnt/a/c/b2
    $ mkdir /mnt/a/e

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mv /mnt/a/c/b2 /mnt/a/e/b3
    $ mkdir /mnt/a/e/b3/f
    $ mkdir /mnt/a/h
    $ mv /mnt/a/c /mnt/a/e/b3/f/c2
    $ mv /mnt/a/e /mnt/a/h/e2

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

Another simple reproducer for case 2)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir /mnt/a/c
    $ mkdir /mnt/a/b/d
    $ mkdir /mnt/a/c/e

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mkdir /mnt/a/b/d/f
    $ mkdir /mnt/a/b/g
    $ mv /mnt/a/c/e /mnt/a/b/g/e2
    $ mv /mnt/a/c /mnt/a/b/d/f/c2
    $ mv /mnt/a/b/d/f /mnt/a/b/g/e2/f2

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

More complex reproducer for case 2)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir -p /mnt/a/c/d
    $ mkdir /mnt/a/b/e
    $ mkdir /mnt/a/c/d/f
    $ mv /mnt/a/b /mnt/a/c/d/2b
    $ mkdir /mnt/a/x
    $ mkdir /mnt/a/y

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mv /mnt/a/x /mnt/a/y
    $ mv /mnt/a/c/d/2b/e /mnt/a/c/d/2b/2e
    $ mv /mnt/a/c/d /mnt/a/h/2d
    $ mv /mnt/a/c /mnt/a/h/2d/2b/2c

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

For both cases the incremental send would enter an infinite loop when building
path strings.

While solving these cases, this change also re-implements the code to detect
when directory moves/renames should be delayed. Instead of dealing with several
specific cases separately, it's now more generic handling all cases with a simple
detection algorithm and if when applying a delayed move/rename there's a path loop
detected, it further delays the move/rename registering a new ancestor inode as
the dependency inode (so our rename happens after that ancestor is renamed).

Tests for these cases is being added to xfstests too.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:40 -07:00
Filipe Manana a10c40766c Btrfs: send, remove dead code from __get_cur_name_and_parent
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:39 -07:00
Filipe Manana c992ec94f2 Btrfs: send, account for orphan directories when building path strings
If we have directories with a pending move/rename operation, we must take into
account any orphan directories that got created before executing the pending
move/rename. Those orphan directories are directories with an inode number higher
then the current send progress and that don't exist in the parent snapshot, they
are created before current progress reaches their inode number, with a generated
name of the form oN-M-I and at the root of the filesystem tree, and later when
progress matches their inode number, moved/renamed to their final location.

Reproducer:

          $ mkfs.btrfs -f /dev/sdd
          $ mount /dev/sdd /mnt

          $ mkdir -p /mnt/a/b/c/d
          $ mkdir /mnt/a/b/e
          $ mv /mnt/a/b/c /mnt/a/b/e/CC
          $ mkdir /mnt/a/b/e/CC/d/f
	  $ mkdir /mnt/a/g

          $ btrfs subvolume snapshot -r /mnt /mnt/snap1
          $ btrfs send /mnt/snap1 -f /tmp/base.send

          $ mkdir /mnt/a/g/h
	  $ mv /mnt/a/b/e /mnt/a/g/h/EE
          $ mv /mnt/a/g/h/EE/CC/d /mnt/a/g/h/EE/DD

          $ btrfs subvolume snapshot -r /mnt /mnt/snap2
          $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

The second receive command failed with the following error:

    ERROR: rename a/b/e/CC/d -> o264-7-0/EE/DD failed. No such file or directory

A test case for xfstests follows soon.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:38 -07:00
Filipe Manana b46ab97bcd Btrfs: send, avoid unnecessary inode item lookup in the btree
Regardless of whether the caller is interested or not in knowing the inode's
generation (dir_gen != NULL), get_first_ref always does a btree lookup to get
the inode item. Avoid this useless lookup if dir_gen parameter is NULL (which
is in some cases).

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:37 -07:00
Gui Hecheng 23f8f9b7ca btrfs: add dev maxs limit for __btrfs_alloc_chunk in kernel space
For RAID0,5,6,10,
For system chunk, there shouldn't be too many stripes to
make a btrfs_chunk that exceeds BTRFS_SYSTEM_CHUNK_ARRAY_SIZE
For data/meta chunk, there shouldn't be too many stripes to
make a btrfs_chunk that exceeds a leaf.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:36 -07:00
Gui Hecheng 5f43f86e3f btrfs: fix wrong max system array size check in kernel space
For system chunk array,
We copy a "disk_key" and an chunk item each time,
so there should be enough space to hold both of them,
not only the chunk item.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:36 -07:00
Qu Wenruo 65d33fd7a6 btrfs: Add check to avoid cleanup roots already in fs_info->dead_roots.
Current btrfs_orphan_cleanup will also cleanup roots which is already in
fs_info->dead_roots without protection.
This will have conditional race with fs_info->cleaner_kthread.

This patch will use refs in root->root_item to detect roots in
dead_roots and avoid conflicts.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:35 -07:00
Miao Xie 21c7e75654 Btrfs: reclaim the reserved metadata space at background
Before applying this patch, the task had to reclaim the metadata space
by itself if the metadata space was not enough. And When the task started
the space reclamation, all the other tasks which wanted to reserve the
metadata space were blocked. At some cases, they would be blocked for
a long time, it made the performance fluctuate wildly.

So we introduce the background metadata space reclamation, when the space
is about to be exhausted, we insert a reclaim work into the workqueue, the
worker of the workqueue helps us to reclaim the reserved space at the
background. By this way, the tasks needn't reclaim the space by themselves at
most cases, and even if the tasks have to reclaim the space or are blocked
for the space reclamation, they will get enough space more quickly.

Here is my test result(Tested by compilebench):
 Memory:	2GB
 CPU:		2Cores * 1CPU
 Partition:	40GB(SSD)

Test command:
 # compilebench -D <mnt> -m

Without this patch:
 intial create total runs 30 avg 54.36 MB/s (user 0.52s sys 2.44s)
 compile total runs 30 avg 123.72 MB/s (user 0.13s sys 1.17s)
 read compiled tree total runs 3 avg 81.15 MB/s (user 0.74s sys 4.89s)
 delete compiled tree total runs 30 avg 5.32 seconds (user 0.35s sys 4.37s)

With this patch:
 intial create total runs 30 avg 59.80 MB/s (user 0.52s sys 2.53s)
 compile total runs 30 avg 151.44 MB/s (user 0.13s sys 1.11s)
 read compiled tree total runs 3 avg 83.25 MB/s (user 0.76s sys 4.91s)
 delete compiled tree total runs 30 avg 5.29 seconds (user 0.34s sys 4.34s)

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:34 -07:00
Miao Xie 32d6b47fe6 Btrfs: output warning instead of error when loading free space cache failed
If we fail to load a free space cache, we can rebuild it from the extent tree,
so it is not a serious error, we should not output a error message that
would make the users uncomfortable. This patch uses warning message instead
of it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:33 -07:00
Qu Wenruo 5a1972bd9f btrfs: Add ctime/mtime update for btrfs device add/remove.
Btrfs will send uevent to udev inform the device change,
but ctime/mtime for the block device inode is not udpated, which cause
libblkid used by btrfs-progs unable to detect device change and use old
cache, causing 'btrfs dev scan; btrfs dev rmove; btrfs dev scan' give an
error message.

Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:33 -07:00
David Sterba 61155aa04e btrfs: assert that send is not in progres before root deletion
CC: Miao Xie <miaox@cn.fujitsu.com>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:32 -07:00
David Sterba 521e0546c9 btrfs: protect snapshots from deleting during send
The patch "Btrfs: fix protection between send and root deletion"
(18f687d538) does not actually prevent to delete the snapshot
and just takes care during background cleaning, but this seems rather
user unfriendly, this patch implements the idea presented in

http://www.spinics.net/lists/linux-btrfs/msg30813.html

- add an internal root_item flag to denote a dead root
- check if the send_in_progress is set and refuse to delete, otherwise
  set the flag and proceed
- check the flag in send similar to the btrfs_root_readonly checks, for
  all involved roots

The root lookup in send via btrfs_read_fs_root_no_name will check if the
root is really dead or not. If it is, ENOENT, aborted send. If it's
alive, it's protected by send_in_progress, send can continue.

CC: Miao Xie <miaox@cn.fujitsu.com>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:31 -07:00
Daeseok Youn 944a4515b2 btrfs: remove redundant null check in btrfs_dentry_release()
It doesn't need to check NULL for kfree()

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:31 -07:00
Filipe Manana ef3b9af50b Btrfs: implement inode_operations callback tmpfile
This implements the tmpfile callback of struct inode_operations, introduced
in the linux kernel 3.11, and implemented already by some filesystems. This
callback is invoked by the VFS when the flag O_TMPFILE is passed to the open
system call.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
2014-06-09 17:20:30 -07:00
David Sterba e4ef90ff61 btrfs: make FS_INFO ioctl available to anyone
This ioctl provides basic info about the filesystem that can be obtained
in other ways (eg. sysfs), there's no reason to restrict it to
CAP_SYSADMIN.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:29 -07:00
David Sterba 7d6213c5a7 btrfs: make DEV_INFO ioctl available to anyone
This ioctl provides basic info about the devices that can be obtained in
other ways (eg. sysfs), there's no reason to restrict it to
CAP_SYSADMIN.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:28 -07:00
David Sterba df93589a17 btrfs: export more from FS_INFO to sysfs
Similar to the FS_INFO updates, export the basic filesystem info through
sysfs: node size, sector size and clone alignment.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:28 -07:00
David Sterba 80a773fbfc btrfs: retrieve more info from FS_INFO ioctl
Provide the basic information about filesystem through the ioctl:
* b-tree node size (same as leaf size)
* sector size
* expected alignment of CLONE_RANGE and EXTENT_SAME ioctl arguments

Backward compatibility: if the values are 0, kernel does not provide
this information, the applications should ignore them.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:27 -07:00
David Sterba 7d824b6f9c btrfs: balance filter: add limit of processed chunks
This started as debugging helper, to watch the effects of converting
between raid levels on multiple devices, but could be useful standalone.

In my case the usage filter was not finegrained enough and led to
converting too many chunks at once. Another example use is in connection
with drange+devid or vrange filters that allow to work with a specific
chunk or even with a chunk on a given device.

The limit filter applies last, the value of 0 means no limiting.

CC: Ilya Dryomov <idryomov@gmail.com>
CC: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:26 -07:00
Filipe Manana fc19c5e736 Btrfs: fix leaf corruption caused by ENOSPC while hole punching
While running a stress test with multiple threads writing to the same btrfs
file system, I ended up with a situation where a leaf was corrupted in that
it had 2 file extent item keys that had the same exact key. I was able to
detect this quickly thanks to the following patch which triggers an assertion
as soon as a leaf is marked dirty if there are duplicated keys or out of order
keys:

    Btrfs: check if items are ordered when a leaf is marked dirty
    (https://patchwork.kernel.org/patch/3955431/)

Basically while running the test, I got the following in dmesg:

    [28877.415877] WARNING: CPU: 2 PID: 10706 at fs/btrfs/file.c:553 btrfs_drop_extent_cache+0x435/0x440 [btrfs]()
    (...)
    [28877.415917] Call Trace:
    [28877.415922]  [<ffffffff816f1189>] dump_stack+0x4e/0x68
    [28877.415926]  [<ffffffff8104a32c>] warn_slowpath_common+0x8c/0xc0
    [28877.415929]  [<ffffffff8104a37a>] warn_slowpath_null+0x1a/0x20
    [28877.415944]  [<ffffffffa03775a5>] btrfs_drop_extent_cache+0x435/0x440 [btrfs]
    [28877.415949]  [<ffffffff8118e7be>] ? kmem_cache_alloc+0xfe/0x1c0
    [28877.415962]  [<ffffffffa03777d9>] fill_holes+0x229/0x3e0 [btrfs]
    [28877.415972]  [<ffffffffa0345865>] ? block_rsv_add_bytes+0x55/0x80 [btrfs]
    [28877.415984]  [<ffffffffa03792cb>] btrfs_fallocate+0xb6b/0xc20 [btrfs]
    (...)
    [29854.132560] BTRFS critical (device sdc): corrupt leaf, bad key order: block=955232256,root=1, slot=24
    [29854.132565] BTRFS info (device sdc): leaf 955232256 total ptrs 40 free space 778
    (...)
    [29854.132637] 	item 23 key (3486 108 667648) itemoff 2694 itemsize 53
    [29854.132638] 		extent data disk bytenr 14574411776 nr 286720
    [29854.132639] 		extent data offset 0 nr 286720 ram 286720
    [29854.132640] 	item 24 key (3486 108 954368) itemoff 2641 itemsize 53
    [29854.132641] 		extent data disk bytenr 0 nr 0
    [29854.132643] 		extent data offset 0 nr 0 ram 0
    [29854.132644] 	item 25 key (3486 108 954368) itemoff 2588 itemsize 53
    [29854.132645] 		extent data disk bytenr 8699670528 nr 77824
    [29854.132646] 		extent data offset 0 nr 77824 ram 77824
    [29854.132647] 	item 26 key (3486 108 1146880) itemoff 2535 itemsize 53
    [29854.132648] 		extent data disk bytenr 8699670528 nr 77824
    [29854.132649] 		extent data offset 0 nr 77824 ram 77824
    (...)
    [29854.132707] kernel BUG at fs/btrfs/ctree.h:3901!
    (...)
    [29854.132771] Call Trace:
    [29854.132779]  [<ffffffffa0342b5c>] setup_items_for_insert+0x2dc/0x400 [btrfs]
    [29854.132791]  [<ffffffffa0378537>] __btrfs_drop_extents+0xba7/0xdd0 [btrfs]
    [29854.132794]  [<ffffffff8109c0d6>] ? trace_hardirqs_on_caller+0x16/0x1d0
    [29854.132797]  [<ffffffff8109c29d>] ? trace_hardirqs_on+0xd/0x10
    [29854.132800]  [<ffffffff8118e7be>] ? kmem_cache_alloc+0xfe/0x1c0
    [29854.132810]  [<ffffffffa036783b>] insert_reserved_file_extent.constprop.66+0xab/0x310 [btrfs]
    [29854.132820]  [<ffffffffa036a6c6>] __btrfs_prealloc_file_range+0x116/0x340 [btrfs]
    [29854.132830]  [<ffffffffa0374d53>] btrfs_prealloc_file_range+0x23/0x30 [btrfs]
    (...)

So this is caused by getting an -ENOSPC error while punching a file hole, more
specifically, we get -ENOSPC error from __btrfs_drop_extents in the while loop
of file.c:btrfs_punch_hole() when it's unable to modify the btree to delete one
or more file extent items due to lack of enough free space. When this happens,
in btrfs_punch_hole(), we attempt to reclaim free space by switching our transaction
block reservation object to root->fs_info->trans_block_rsv, end our transaction and
start a new transaction basically - and, we keep increasing our current offset
(cur_offset) as long as it's smaller than the end of the target range (lockend) -
this makes use leave the loop with cur_offset == drop_end which in turn makes us
call fill_holes() for inserting a file extent item that represents a 0 bytes range
hole (and this insertion succeeds, as in the meanwhile more space became available).

This 0 bytes file hole extent item is a problem because any subsequent caller of
__btrfs_drop_extents (regular file writes, or fallocate calls for e.g.), with a
start file offset that is equal to the offset of the hole, will not remove this
extent item due to the following conditional in the while loop of
__btrfs_drop_extents:

    if (extent_end <= search_start) {
            path->slots[0]++;
            goto next_slot;
    }

This later makes the call to setup_items_for_insert() (at the very end of
__btrfs_drop_extents), insert a new file extent item with the same offset as
the 0 bytes file hole extent item that follows it. Needless is to say that this
causes chaos, either when reading the leaf from disk (btree_readpage_end_io_hook),
where we perform leaf sanity checks or in subsequent operations that manipulate
file extent items, as in the fallocate call as shown by the dmesg trace above.

Without my other patch to perform the leaf sanity checks once a leaf is marked
as dirty (if the integrity checker is enabled), it would have been much harder
to debug this issue.

This change might fix a few similar issues reported by users in the mailing
list regarding assertion failures in btrfs_set_item_key_safe calls performed
by __btrfs_drop_extents, such as the following report:

    http://comments.gmane.org/gmane.comp.file-systems.btrfs/32938

Asking fill_holes() to create a 0 bytes wide file hole item also produced the
first warning in the trace above, as we passed a range to btrfs_drop_extent_cache
that has an end smaller (by -1) than its start.

On 3.14 kernels this issue manifests itself through leaf corruption, as we get
duplicated file extent item keys in a leaf when calling setup_items_for_insert(),
but on older kernels, setup_items_for_insert() isn't called by __btrfs_drop_extents(),
instead we have callers of __btrfs_drop_extents(), namely the functions
inode.c:insert_inline_extent() and inode.c:insert_reserved_file_extent(), calling
btrfs_insert_empty_item() to insert the new file extent item, which would fail with
error -EEXIST, instead of inserting a duplicated key - which is still a serious
issue as it would make all similar file extent item replace operations keep
failing if they target the same file range.

Cc: stable@vger.kernel.org
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:26 -07:00
Liu Bo d2cbf2a260 Btrfs: do not increment on bio_index one by one
'bio_index' is just a index, it's really not necessary to do increment
one by one.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:25 -07:00
Filipe Manana a1a50f60a6 Btrfs: read inode size after acquiring the mutex when punching a hole
In a previous change, commit 12870f1c9b,
I accidentally moved the roundup of inode->i_size to outside of the
critical section delimited by the inode mutex, which is not atomic and
not correct since the size can be changed by other task before we acquire
the mutex. Therefore fix it.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:24 -07:00
Tobias Klauser 7fb18a0664 btrfs: Remove unnecessary check for NULL
iput() already checks for the inode being NULL, thus it's unnecessary to
check before calling.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:23 -07:00
Zach Brown 166ae5a418 btrfs: fix inline compressed read err corruption
uncompress_inline() is dropping the error from btrfs_decompress() after
testing it and zeroing the page that was supposed to hold decompressed
data.  This can silently turn compressed inline data in to zeros if
decompression fails due to corrupt compressed data or memory allocation
failure.

I verified this by manually forcing the error from btrfs_decompress()
for a silly named copy of od:

	if (!strcmp(current->comm, "failod"))
		ret = -ENOMEM;

  # od -x /mnt/btrfs/dir/80 | head -1
  0000000 3031 3038 310a 2d30 6f70 6e69 0a74 3031
  # echo 3 > /proc/sys/vm/drop_caches
  # cp $(which od) /tmp/failod
  # /tmp/failod -x /mnt/btrfs/dir/80 | head -1
  0000000 0000 0000 0000 0000 0000 0000 0000 0000

The fix is to pass the error to its caller.  Which still has a BUG_ON().
So we fix that too.

There seems to be no reason for the zeroing of the page on the error
from btrfs_decompress() but not from the allocation error a few lines
above.  So the page zeroing is removed.

Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:23 -07:00
Zach Brown 774bcb35f0 btrfs: return ptr error from compression workspace
The btrfs compression wrappers translated errors from workspace
allocation to either -ENOMEM or -1.  The compression type workspace
allocators are already returning a ERR_PTR(-ENOMEM).  Just return that
and get rid of the magical -1.

This helps a future patch return errors from the compression wrappers.

Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:22 -07:00
Zach Brown 60e1975acb btrfs: return errno instead of -1 from compression
The compression layer seems to have been built to return -1 and have
callers make up errors that make sense.  This isn't great because there
are different errors that originate down in the compression layer.

Let's return real negative errnos from the compression layer so that
callers can pass on the error without having to guess what happened.
ENOMEM for allocation failure, E2BIG when compression exceeds the
uncompressed input, and EIO for everything else.

This helps a future path return errors from btrfs_decompress().

Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:21 -07:00
Stefan Behrens 98806b446d btrfs: check_int: propagate out-of-memory error upwards
This issue was not causing any harm but IMO (and in the opinion of the
static code checker) it is better to propagate this error status upwards.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:21 -07:00
Filipe Manana 61391d5622 Btrfs: fix hang on error (such as ENOSPC) when writing extent pages
When running low on available disk space and having several processes
doing buffered file IO, I got the following trace in dmesg:

[ 4202.720152] INFO: task kworker/u8:1:5450 blocked for more than 120 seconds.
[ 4202.720401]       Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.720596] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.720874] kworker/u8:1    D 0000000000000001     0  5450      2 0x00000000
[ 4202.720904] Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs]
[ 4202.720908]  ffff8801f62ddc38 0000000000000082 ffff880203ac2490 00000000001d3f40
[ 4202.720913]  ffff8801f62ddfd8 00000000001d3f40 ffff8800c4f0c920 ffff880203ac2490
[ 4202.720918]  00000000001d4a40 ffff88020fe85a40 ffff88020fe85ab8 0000000000000001
[ 4202.720922] Call Trace:
[ 4202.720931]  [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.720950]  [<ffffffffa01ec48d>] btrfs_start_ordered_extent+0x6d/0x110 [btrfs]
[ 4202.720956]  [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.720972]  [<ffffffffa01ec559>] btrfs_run_ordered_extent_work+0x29/0x40 [btrfs]
[ 4202.720988]  [<ffffffffa0201987>] normal_work_helper+0x137/0x2c0 [btrfs]
[ 4202.720994]  [<ffffffff810680e5>] process_one_work+0x1f5/0x530
(...)
[ 4202.721027] 2 locks held by kworker/u8:1/5450:
[ 4202.721028]  #0:  (%s-%s){++++..}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721037]  #1:  ((&work->normal_work)){+.+...}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721054] INFO: task btrfs:7891 blocked for more than 120 seconds.
[ 4202.721258]       Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.721444] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.721699] btrfs           D 0000000000000001     0  7891   7890 0x00000001
[ 4202.721704]  ffff88018c2119e8 0000000000000086 ffff8800a33d2490 00000000001d3f40
[ 4202.721710]  ffff88018c211fd8 00000000001d3f40 ffff8802144b0000 ffff8800a33d2490
[ 4202.721714]  ffff8800d8576640 ffff88020fe85bc0 ffff88020fe85bc8 7fffffffffffffff
[ 4202.721718] Call Trace:
[ 4202.721723]  [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.721727]  [<ffffffff816a2ebc>] schedule_timeout+0x1dc/0x270
[ 4202.721732]  [<ffffffff8109bd79>] ? mark_held_locks+0xb9/0x140
[ 4202.721736]  [<ffffffff816a90c0>] ? _raw_spin_unlock_irq+0x30/0x40
[ 4202.721740]  [<ffffffff8109bf0d>] ? trace_hardirqs_on_caller+0x10d/0x1d0
[ 4202.721744]  [<ffffffff816a488f>] wait_for_completion+0xdf/0x120
[ 4202.721749]  [<ffffffff8107fa90>] ? try_to_wake_up+0x310/0x310
[ 4202.721765]  [<ffffffffa01ebee4>] btrfs_wait_ordered_extents+0x1f4/0x280 [btrfs]
[ 4202.721781]  [<ffffffffa020526e>] btrfs_mksubvol.isra.62+0x30e/0x5a0 [btrfs]
[ 4202.721786]  [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.721799]  [<ffffffffa02056a9>] btrfs_ioctl_snap_create_transid+0x1a9/0x1b0 [btrfs]
[ 4202.721813]  [<ffffffffa020583a>] btrfs_ioctl_snap_create_v2+0x10a/0x170 [btrfs]
(...)

It turns out that extent_io.c:__extent_writepage(), which ends up being called
through filemap_fdatawrite_range() in btrfs_start_ordered_extent(), was getting
-ENOSPC when calling the fill_delalloc callback. In this situation, it returned
without the writepage_end_io_hook callback (inode.c:btrfs_writepage_end_io_hook)
ever being called for the respective page, which prevents the ordered extent's
bytes_left count from ever reaching 0, and therefore a finish_ordered_fn work
is never queued into the endio_write_workers queue. This makes the task that
called btrfs_start_ordered_extent() hang forever on the wait queue of the ordered
extent.

This is fairly easy to reproduce using a small filesystem and fsstress on
a quad core vm:

    mkfs.btrfs -f -b `expr 2100 \* 1024 \* 1024` /dev/sdd
    mount /dev/sdd /mnt

    fsstress -p 6 -d /mnt -n 100000 -x \
        "btrfs subvolume snapshot -r /mnt /mnt/mysnap" \
	    -f allocsp=0 \
	    -f bulkstat=0 \
	    -f bulkstat1=0 \
	    -f chown=0 \
	    -f creat=1 \
	    -f dread=0 \
	    -f dwrite=0 \
	    -f fallocate=1 \
	    -f fdatasync=0 \
	    -f fiemap=0 \
	    -f freesp=0 \
	    -f fsync=0 \
	    -f getattr=0 \
	    -f getdents=0 \
	    -f link=0 \
	    -f mkdir=0 \
	    -f mknod=0 \
	    -f punch=1 \
	    -f read=0 \
	    -f readlink=0 \
	    -f rename=0 \
	    -f resvsp=0 \
	    -f rmdir=0 \
	    -f setxattr=0 \
	    -f stat=0 \
	    -f symlink=0 \
	    -f sync=0 \
	    -f truncate=1 \
	    -f unlink=0 \
	    -f unresvsp=0 \
	    -f write=4

So just ensure that if an error happens while writing the extent page
we call the writepage_end_io_hook callback. Also make it return the
error code and ensure the caller (extent_write_cache_pages) processes
all pages in the page vector even if an error happens only for some
of them, so that ordered extents end up released.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:20 -07:00
Linus Torvalds 3f17ea6dea Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...
2014-06-08 11:31:16 -07:00
Filipe Manana 01a9a8a9e2 Btrfs: send, fix corrupted path strings for long paths
If a path has more than 230 characters, we allocate a new buffer to
use for the path, but we were forgotting to copy the contents of the
previous buffer into the new one, which has random content from the
kmalloc call.

Test:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    TEST_PATH="/mnt/fdmanana/.config/google-chrome-mysetup/Default/Pepper_Data/Shockwave_Flash/WritableRoot/#SharedObjects/JSHJ4ZKN/s.wsj.net/[[IMPORT]]/players.edgesuite.net/flash/plugins/osmf/advanced-streaming-plugin/v2.7/osmf1.6/Ak#"
    mkdir -p $TEST_PATH
    echo "hello world" > $TEST_PATH/amaiAdvancedStreamingPlugin.txt

    btrfs subvolume snapshot -r /mnt /mnt/mysnap1
    btrfs send /mnt/mysnap1 -f /tmp/1.snap

A test for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Cc: Marc Merlin <marc@merlins.org>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-06 12:00:46 -07:00
Mel Gorman 2457aec637 mm: non-atomically mark page accessed during page cache allocation where possible
aops->write_begin may allocate a new page and make it visible only to have
mark_page_accessed called almost immediately after.  Once the page is
visible the atomic operations are necessary which is noticable overhead
when writing to an in-memory filesystem like tmpfs but should also be
noticable with fast storage.  The objective of the patch is to initialse
the accessed information with non-atomic operations before the page is
visible.

The bulk of filesystems directly or indirectly use
grab_cache_page_write_begin or find_or_create_page for the initial
allocation of a page cache page.  This patch adds an init_page_accessed()
helper which behaves like the first call to mark_page_accessed() but may
called before the page is visible and can be done non-atomically.

The primary APIs of concern in this care are the following and are used
by most filesystems.

	find_get_page
	find_lock_page
	find_or_create_page
	grab_cache_page_nowait
	grab_cache_page_write_begin

All of them are very similar in detail to the patch creates a core helper
pagecache_get_page() which takes a flags parameter that affects its
behavior such as whether the page should be marked accessed or not.  Then
old API is preserved but is basically a thin wrapper around this core
function.

Each of the filesystems are then updated to avoid calling
mark_page_accessed when it is known that the VM interfaces have already
done the job.  There is a slight snag in that the timing of the
mark_page_accessed() has now changed so in rare cases it's possible a page
gets to the end of the LRU as PageReferenced where as previously it might
have been repromoted.  This is expected to be rare but it's worth the
filesystem people thinking about it in case they see a problem with the
timing change.  It is also the case that some filesystems may be marking
pages accessed that previously did not but it makes sense that filesystems
have consistent behaviour in this regard.

The test case used to evaulate this is a simple dd of a large file done
multiple times with the file deleted on each iterations.  The size of the
file is 1/10th physical memory to avoid dirty page balancing.  In the
async case it will be possible that the workload completes without even
hitting the disk and will have variable results but highlight the impact
of mark_page_accessed for async IO.  The sync results are expected to be
more stable.  The exception is tmpfs where the normal case is for the "IO"
to not hit the disk.

The test machine was single socket and UMA to avoid any scheduling or NUMA
artifacts.  Throughput and wall times are presented for sync IO, only wall
times are shown for async as the granularity reported by dd and the
variability is unsuitable for comparison.  As async results were variable
do to writback timings, I'm only reporting the maximum figures.  The sync
results were stable enough to make the mean and stddev uninteresting.

The performance results are reported based on a run with no profiling.
Profile data is based on a separate run with oprofile running.

async dd
                                    3.15.0-rc3            3.15.0-rc3
                                       vanilla           accessed-v2
ext3    Max      elapsed     13.9900 (  0.00%)     11.5900 ( 17.16%)
tmpfs	Max      elapsed      0.5100 (  0.00%)      0.4900 (  3.92%)
btrfs   Max      elapsed     12.8100 (  0.00%)     12.7800 (  0.23%)
ext4	Max      elapsed     18.6000 (  0.00%)     13.3400 ( 28.28%)
xfs	Max      elapsed     12.5600 (  0.00%)      2.0900 ( 83.36%)

The XFS figure is a bit strange as it managed to avoid a worst case by
sheer luck but the average figures looked reasonable.

        samples percentage
ext3       86107    0.9783  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
ext3       23833    0.2710  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext3        5036    0.0573  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
ext4       64566    0.8961  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
ext4        5322    0.0713  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext4        2869    0.0384  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs        62126    1.7675  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
xfs         1904    0.0554  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs          103    0.0030  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
btrfs      10655    0.1338  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
btrfs       2020    0.0273  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
btrfs        587    0.0079  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
tmpfs      59562    3.2628  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
tmpfs       1210    0.0696  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
tmpfs         94    0.0054  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed

[akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:10 -07:00
Linus Torvalds 776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00
Linus Torvalds 11da37b263 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull two btrfs fixes from Chris Mason:
 "This has two fixes that we've been testing for 3.16, but since both
  are safe and fix real bugs, it makes sense to send for 3.15 instead"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: send, fix incorrect ref access when using extrefs
  Btrfs: fix EIO on reading file after ioctl clone works on it
2014-05-22 05:40:13 +09:00
Filipe Manana 51a60253a5 Btrfs: send, fix incorrect ref access when using extrefs
When running send, if an inode only has extended reference items
associated to it and no regular references, send.c:get_first_ref()
was incorrectly assuming the reference it found was of type
BTRFS_INODE_REF_KEY due to use of the wrong key variable.
This caused weird behaviour when using the found item has a regular
reference, such as weird path string, and occasionally (when lucky)
a crash:

[  190.600652] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[  190.600994] Modules linked in: btrfs xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc psmouse serio_raw evbug pcspkr i2c_piix4 e1000 floppy
[  190.602565] CPU: 2 PID: 14520 Comm: btrfs Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[  190.602728] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  190.602868] task: ffff8800d447c920 ti: ffff8801fa79e000 task.ti: ffff8801fa79e000
[  190.603030] RIP: 0010:[<ffffffff813266b4>]  [<ffffffff813266b4>] memcpy+0x54/0x110
[  190.603262] RSP: 0018:ffff8801fa79f880  EFLAGS: 00010202
[  190.603395] RAX: ffff8800d4326e3f RBX: 000000000000036a RCX: ffff880000000000
[  190.603553] RDX: 000000000000032a RSI: ffe708844042936a RDI: ffff8800d43271a9
[  190.603710] RBP: ffff8801fa79f8c8 R08: 00000000003a4ef0 R09: 0000000000000000
[  190.603867] R10: 793a4ef09f000000 R11: 9f0000000053726f R12: ffff8800d43271a9
[  190.604020] R13: 0000160000000000 R14: ffff8802110134f0 R15: 000000000000036a
[  190.604020] FS:  00007fb423d09b80(0000) GS:ffff880216200000(0000) knlGS:0000000000000000
[  190.604020] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  190.604020] CR2: 00007fb4229d4b78 CR3: 00000001f5d76000 CR4: 00000000000006e0
[  190.604020] Stack:
[  190.604020]  ffffffffa01f4d49 ffff8801fa79f8f0 00000000000009f9 ffff8801fa79f8c8
[  190.604020]  00000000000009f9 ffff880211013260 000000000000f971 ffff88021147dba8
[  190.604020]  00000000000009f9 ffff8801fa79f918 ffffffffa02367f5 ffff8801fa79f928
[  190.604020] Call Trace:
[  190.604020]  [<ffffffffa01f4d49>] ? read_extent_buffer+0xb9/0x120 [btrfs]
[  190.604020]  [<ffffffffa02367f5>] fs_path_add_from_extent_buffer+0x45/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238806>] get_first_ref+0x1f6/0x210 [btrfs]
[  190.604020]  [<ffffffffa0238994>] __get_cur_name_and_parent+0x174/0x3a0 [btrfs]
[  190.604020]  [<ffffffff8118df3d>] ? kmem_cache_alloc_trace+0x11d/0x1e0
[  190.604020]  [<ffffffffa0236674>] ? fs_path_alloc+0x24/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238c91>] get_cur_path+0xd1/0x240 [btrfs]
(...)

Steps to reproduce (either crash or some weirdness like an odd path string):

    mkfs.btrfs -f -O extref /dev/sdd
    mount /dev/sdd /mnt

    mkdir /mnt/testdir
    touch /mnt/testdir/foobar

    for i in `seq 1 2550`; do
        ln /mnt/testdir/foobar /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    ln /mnt/testdir/foobar /mnt/testdir/final_foobar_name

    rm -f /mnt/testdir/foobar
    for i in `seq 1 2550`; do
        rm -f /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    btrfs subvolume snapshot -r /mnt /mnt/mysnap
    btrfs send /mnt/mysnap -f /tmp/mysnap.send

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2014-05-20 10:18:26 -07:00
Liu Bo d3ecfcdf91 Btrfs: fix EIO on reading file after ioctl clone works on it
For inline data extent, we need to make its length aligned, otherwise,
we can get a phantom extent map which confuses readpages() to return -EIO.

This can be detected by xfstests/btrfs/035.

Reported-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-05-20 10:17:48 -07:00
Al Viro b30ac0fc41 btrfs: switch to ->write_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:39:41 -04:00
Al Viro aad4f8bb42 switch simple generic_file_aio_read() users to ->read_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:37:55 -04:00
Al Viro 0c949334a9 iov_iter_truncate()
Now It Can Be Done(tm) - we don't need to do iov_shorten() in
generic_file_direct_write() anymore, now that all ->direct_IO()
instances are converted to proper iov_iter methods and honour
iter->count and iter->iov_offset properly.

Get rid of count/ocount arguments of generic_file_direct_write(),
while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:54 -04:00
Al Viro 28060d5d9b btrfs: switch check_direct_IO() to iov_iter
... and don't open-code iov_iter_alignment() there

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:53 -04:00
Al Viro 71d8e532b1 start adding the tag to iov_iter
For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment.  Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:49 -04:00
Al Viro 31b140398c switch {__,}blockdev_direct_IO() to iov_iter
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:46 -04:00
Al Viro a6cbcd4a4a get rid of pointless iov_length() in ->direct_IO()
all callers have iov_length(iter->iov, iter->nr_segs) == iov_iter_count(iter)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:45 -04:00
Al Viro d8d3d94b80 pass iov_iter to ->direct_IO()
unmodified, for now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:44 -04:00
Al Viro cb66a7a1f1 kill generic_segment_checks()
all callers of ->aio_read() and ->aio_write() have iov/nr_segs already
checked - generic_segment_checks() done after that is just an odd way
to spell iov_length().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:43 -04:00