This is a better solution for the problem addressed in the following
commit:
Btrfs: update commit root on snapshot creation after orphan cleanup
(3821f34888)
The previous solution wasn't the best because of 2 reasons:
1) It added another full transaction commit, which is more expensive
than just swapping the commit root with the root;
2) If a reboot happened after the first transaction commit (the one
that creates the snapshot) and before the second transaction commit,
then we would end up with the same problem if a send using that
snapshot was requested before the first transaction commit after
the reboot.
This change addresses those 2 issues. The second issue is addressed by
switching the commit root in the dentry lookup VFS callback, which is
also called by the snapshot/subvol creation ioctl and performs orphan
cleanup if needed. Like the vfs, the ioctl locks the parent inode too,
preventing race issues between a dentry lookup and snapshot creation.
Cc: Alex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Pull btrfs fixes from Chris Mason:
"We've queued up a few fixes in my for-linus branch"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix crash when starting transaction
Btrfs: fix btrfs_print_leaf for skinny metadata
Btrfs: fix race of using total_bytes_pinned
btrfs: use E2BIG instead of EIO if compression does not help
btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
Btrfs: fix use-after-free when cloning a trailing file hole
btrfs: fix null pointer dereference in btrfs_show_devname when name is null
btrfs: fix null pointer dereference in clone_fs_devices when name is null
btrfs: fix nossd and ssd_spread mount option regression
Btrfs: fix race between balance recovery and root deletion
Btrfs: atomically set inode->i_flags in btrfs_update_iflags
btrfs: only unlock block in verify_parent_transid if we locked it
Btrfs: assert send doesn't attempt to start transactions
btrfs compression: reuse recently used workspace
Btrfs: fix crash when mounting raid5 btrfs with missing disks
btrfs: create sprout should rename fsid on the sysfs as well
btrfs: dev replace should replace the sysfs entry
btrfs: dev add should add its sysfs entry
btrfs: dev delete should remove sysfs entry
btrfs: rename add_device_membership to btrfs_kobj_add_device
The transaction handle was being used after being freed.
Cc: Chris Mason <clm@fb.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
This change is based on the corresponding recent change for ext4:
ext4: atomically set inode->i_flags in ext4_set_inode_flags()
That has the following commit message that applies to btrfs as well:
"Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time."
Replacing EXT4_IMMUTABLE_FL and EXT4_APPEND_FL with BTRFS_INODE_IMMUTABLE
and BTRFS_INODE_APPEND, respectively.
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Pull more btrfs updates from Chris Mason:
"This has a few fixes since our last pull and a new ioctl for doing
btree searches from userland. It's very similar to the existing
ioctl, but lets us return larger items back down to the app"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix error handling in create_pending_snapshot
btrfs: fix use of uninit "ret" in end_extent_writepage()
btrfs: free ulist in qgroup_shared_accounting() error path
Btrfs: fix qgroups sanity test crash or hang
btrfs: prevent RCU warning when dereferencing radix tree slot
Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
btrfs: new ioctl TREE_SEARCH_V2
btrfs: tree_search, search_ioctl: direct copy to userspace
btrfs: new function read_extent_buffer_to_user
btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
btrfs: tree_search, search_ioctl: accept varying buffer
btrfs: tree_search: eliminate redundant nr_items check
This new ioctl call allows the user to supply a buffer of varying size in which
a tree search can store its results. This is much more flexible if you want to
receive items which are larger than the current fixed buffer of 3992 bytes or
if you want to fetch more items at once. Items larger than this buffer are for
example some of the type EXTENT_CSUM.
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
By copying each found item seperatly to userspace, we do not need extra
buffer in the kernel.
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
If an item in tree_search is too large to be stored in the given buffer, return
the needed size (including the header).
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
In copy_to_sk, if an item is too large for the given buffer, it now returns
-EOVERFLOW instead of copying a search_header with len = 0. For backward
compatibility for the first item it still copies such a header to the buffer,
but not any other following items, which could have fitted.
tree_search changes -EOVERFLOW back to 0 to behave similiar to the way it
behaved before this patch.
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
rewrite search_ioctl to accept a buffer with varying size
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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>
Pull btrfs fixes from Chris Mason.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: limit the path size in send to PATH_MAX
Btrfs: correctly set profile flags on seqlock retry
Btrfs: use correct key when repeating search for extent item
Btrfs: fix inode caching vs tree log
Btrfs: fix possible memory leaks in open_ctree()
Btrfs: avoid triggering bug_on() when we fail to start inode caching task
Btrfs: move btrfs_{set,clear}_and_info() to ctree.h
btrfs: replace error code from btrfs_drop_extents
btrfs: Change the hole range to a more accurate value.
btrfs: fix use-after-free in mount_subvol()
There's a case which clone does not handle and used to BUG_ON instead,
(testcase xfstests/btrfs/035), now returns EINVAL. This error code is
confusing to the ioctl caller, as it normally signifies errorneous
arguments.
Change it to ENOPNOTSUPP which allows a fall back to copy instead of
clone. This does not affect the common reflink operation.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Pull second set of btrfs updates from Chris Mason:
"The most important changes here are from Josef, fixing a btrfs
regression in 3.14 that can cause corruptions in the extent allocation
tree when snapshots are in use.
Josef also fixed some deadlocks in send/recv and other assorted races
when balance is running"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (23 commits)
Btrfs: fix compile warnings on on avr32 platform
btrfs: allow mounting btrfs subvolumes with different ro/rw options
btrfs: export global block reserve size as space_info
btrfs: fix crash in remount(thread_pool=) case
Btrfs: abort the transaction when we don't find our extent ref
Btrfs: fix EINVAL checks in btrfs_clone
Btrfs: fix unlock in __start_delalloc_inodes()
Btrfs: scrub raid56 stripes in the right way
Btrfs: don't compress for a small write
Btrfs: more efficient io tree navigation on wait_extent_bit
Btrfs: send, build path string only once in send_hole
btrfs: filter invalid arg for btrfs resize
Btrfs: send, fix data corruption due to incorrect hole detection
Btrfs: kmalloc() doesn't return an ERR_PTR
Btrfs: fix snapshot vs nocow writting
btrfs: Change the expanding write sequence to fix snapshot related bug.
btrfs: make device scan less noisy
btrfs: fix lockdep warning with reclaim lock inversion
Btrfs: hold the commit_root_sem when getting the commit root during send
Btrfs: remove transaction from send
...
Introduce a block group type bit for a global reserve and fill the space
info for SPACE_INFO ioctl. This should replace the newly added ioctl
(01e219e806) to get just the 'size' part
of the global reserve, while the actual usage can be now visible in the
'btrfs fi df' output during ENOSPC stress.
The unpatched userspace tools will show the blockgroup as 'unknown'.
CC: Jeff Mahoney <jeffm@suse.com>
CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
btrfs_drop_extents can now return -EINVAL, but only one caller
in btrfs_clone was checking for it. This adds it to the
caller for inline extents, which is where we really need it.
Signed-off-by: Chris Mason <clm@fb.com>
Originally following cmds will work:
# btrfs fi resize -10A <mnt>
# btrfs fi resize -10Gaha <mnt>
Filter the arg by checking the return pointer of memparse.
Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
The error handling was copy and pasted from memdup_user(). It should be
checking for NULL obviously.
Fixes: abccd00f8a ('btrfs: Fix 32/64-bit problem with BTRFS_SET_RECEIVED_SUBVOL ioctl')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Pull btrfs changes from Chris Mason:
"This is a pretty long stream of bug fixes and performance fixes.
Qu Wenruo has replaced the btrfs async threads with regular kernel
workqueues. We'll keep an eye out for performance differences, but
it's nice to be using more generic code for this.
We still have some corruption fixes and other patches coming in for
the merge window, but this batch is tested and ready to go"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (108 commits)
Btrfs: fix a crash of clone with inline extents's split
btrfs: fix uninit variable warning
Btrfs: take into account total references when doing backref lookup
Btrfs: part 2, fix incremental send's decision to delay a dir move/rename
Btrfs: fix incremental send's decision to delay a dir move/rename
Btrfs: remove unnecessary inode generation lookup in send
Btrfs: fix race when updating existing ref head
btrfs: Add trace for btrfs_workqueue alloc/destroy
Btrfs: less fs tree lock contention when using autodefrag
Btrfs: return EPERM when deleting a default subvolume
Btrfs: add missing kfree in btrfs_destroy_workqueue
Btrfs: cache extent states in defrag code path
Btrfs: fix deadlock with nested trans handles
Btrfs: fix possible empty list access when flushing the delalloc inodes
Btrfs: split the global ordered extents mutex
Btrfs: don't flush all delalloc inodes when we doesn't get s_umount lock
Btrfs: reclaim delalloc metadata more aggressively
Btrfs: remove unnecessary lock in may_commit_transaction()
Btrfs: remove the unnecessary flush when preparing the pages
Btrfs: just do dirty page flush for the inode with compression before direct IO
...
xfstests's btrfs/035 triggers a BUG_ON, which we use to detect the split
of inline extents in __btrfs_drop_extents().
For inline extents, we cannot duplicate another EXTENT_DATA item, because
it breaks the rule of inline extents, that is, 'start offset' needs to be 0.
We have set limitations for the source inode's compressed inline extents,
because it needs to decompress and recompress. Now the destination inode's
inline extents also need similar limitations.
With this, xfstests btrfs/035 doesn't run into panic.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
When finding new extents during an autodefrag, don't do so many fs tree
lookups to find an extent with a size smaller then the target treshold.
Instead, after each fs tree forward search immediately unlock upper
levels and process the entire leaf while holding a read lock on the leaf,
since our leaf processing is very fast.
This reduces lock contention, allowing for higher concurrency when other
tasks want to write/update items related to other inodes in the fs tree,
as we're not holding read locks on upper tree levels while processing the
leaf and we do less tree searches.
Test:
sysbench --test=fileio --file-num=512 --file-total-size=16G \
--file-test-mode=rndrw --num-threads=32 --file-block-size=32768 \
--file-rw-ratio=3 --file-io-mode=sync --max-time=1800 \
--max-requests=10000000000 [prepare|run]
(fileystem mounted with -o autodefrag, averages of 5 runs)
Before this change: 58.852Mb/sec throughtput, read 77.589Gb, written 25.863Gb
After this change: 63.034Mb/sec throughtput, read 83.102Gb, written 27.701Gb
Test machine: quad core intel i5-3570K, 32Gb of RAM, SSD.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
The error message is confusing:
# btrfs sub delete /mnt/mysub/
Delete subvolume '/mnt/mysub'
ERROR: cannot delete '/mnt/mysub' - Directory not empty
The error message does not make sense to me: It's not about deleting a
directory but it's a subvolume, and it doesn't matter if the subvolume is
empty or not.
Maybe EPERM or is more appropriate in this case, combined with an explanatory
kernel log message. (e.g. "subvolume with ID 123 cannot be deleted because
it is configured as default subvolume.")
Reported-by: Koen De Wit <koen.de.wit@oracle.com>
Signed-off-by: Guangyu Sun <guangyu.sun@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
When locking file ranges in the inode's io_tree, cache the first
extent state that belongs to the target range, so that when unlocking
the range we don't need to search in the io_tree again, reducing cpu
time and making and therefore holding the io_tree's lock for a shorter
period.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
We needn't flush all delalloc inodes when we doesn't get s_umount lock,
or we would make the tasks wait for a long time.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
If the snapshot creation happened after the nocow write but before the dirty
data flush, we would fail to flush the dirty data because of no space.
So we must keep track of when those nocow write operations start and when they
end, if there are nocow writers, the snapshot creators must wait. In order
to implement this function, I introduce btrfs_{start, end}_nocow_write(),
which is similar to mnt_{want,drop}_write().
These two functions are only used for nocow file write operations.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
When using prealloc extents, a file defragment operation may actually
fragment the file and increase the amount of data space used by the file.
This change fixes that behaviour.
Example:
$ mkfs.btrfs -f /dev/sdb3
$ mount /dev/sdb3 /mnt
$ cd /mnt
$ xfs_io -f -c 'falloc 0 1048576' foobar && sync
$ xfs_io -c 'pwrite -S 0xff -b 100000 5000 100000' foobar
$ xfs_io -c 'pwrite -S 0xac -b 100000 200000 100000' foobar
$ xfs_io -c 'pwrite -S 0xe1 -b 100000 900000 100000' foobar && sync
Before defragmenting the file:
$ btrfs filesystem df /mnt
Data, single: total=8.00MiB, used=1.25MiB
System, DUP: total=8.00MiB, used=16.00KiB
System, single: total=4.00MiB, used=0.00
Metadata, DUP: total=1.00GiB, used=112.00KiB
Metadata, single: total=8.00MiB, used=0.00
$ btrfs-debug-tree /dev/sdb3
(...)
item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
prealloc data disk byte 12845056 nr 1048576
prealloc data offset 0 nr 4096
item 7 key (257 EXTENT_DATA 4096) itemoff 15757 itemsize 53
extent data disk byte 12845056 nr 1048576
extent data offset 4096 nr 102400 ram 1048576
extent compression 0
item 8 key (257 EXTENT_DATA 106496) itemoff 15704 itemsize 53
prealloc data disk byte 12845056 nr 1048576
prealloc data offset 106496 nr 90112
item 9 key (257 EXTENT_DATA 196608) itemoff 15651 itemsize 53
extent data disk byte 12845056 nr 1048576
extent data offset 196608 nr 106496 ram 1048576
extent compression 0
item 10 key (257 EXTENT_DATA 303104) itemoff 15598 itemsize 53
prealloc data disk byte 12845056 nr 1048576
prealloc data offset 303104 nr 593920
item 11 key (257 EXTENT_DATA 897024) itemoff 15545 itemsize 53
extent data disk byte 12845056 nr 1048576
extent data offset 897024 nr 106496 ram 1048576
extent compression 0
item 12 key (257 EXTENT_DATA 1003520) itemoff 15492 itemsize 53
prealloc data disk byte 12845056 nr 1048576
prealloc data offset 1003520 nr 45056
(...)
Now defragmenting the file results in more data space used than before:
$ btrfs filesystem defragment -f foobar && sync
$ btrfs filesystem df /mnt
Data, single: total=8.00MiB, used=1.55MiB
System, DUP: total=8.00MiB, used=16.00KiB
System, single: total=4.00MiB, used=0.00
Metadata, DUP: total=1.00GiB, used=112.00KiB
Metadata, single: total=8.00MiB, used=0.00
And the corresponding file extent items are now no longer perfectly sequential
as before, and we're now needlessly using more space from data block groups:
$ btrfs-debug-tree /dev/sdb3
(...)
item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
extent data disk byte 12845056 nr 1048576
extent data offset 0 nr 4096 ram 1048576
extent compression 0
item 7 key (257 EXTENT_DATA 4096) itemoff 15757 itemsize 53
extent data disk byte 13893632 nr 102400
extent data offset 0 nr 102400 ram 102400
extent compression 0
item 8 key (257 EXTENT_DATA 106496) itemoff 15704 itemsize 53
extent data disk byte 12845056 nr 1048576
extent data offset 106496 nr 90112 ram 1048576
extent compression 0
item 9 key (257 EXTENT_DATA 196608) itemoff 15651 itemsize 53
extent data disk byte 13996032 nr 106496
extent data offset 0 nr 106496 ram 106496
extent compression 0
item 10 key (257 EXTENT_DATA 303104) itemoff 15598 itemsize 53
prealloc data disk byte 12845056 nr 1048576
prealloc data offset 303104 nr 593920
item 11 key (257 EXTENT_DATA 897024) itemoff 15545 itemsize 53
extent data disk byte 14102528 nr 106496
extent data offset 0 nr 106496 ram 106496
extent compression 0
item 12 key (257 EXTENT_DATA 1003520) itemoff 15492 itemsize 53
extent data disk byte 12845056 nr 1048576
extent data offset 1003520 nr 45056 ram 1048576
extent compression 0
(...)
With this change, the above example will no longer cause allocation of new data
space nor change the sequentiality of the file extents, that is, defragment will
be effectless, leaving all extent items pointing to the extent starting at disk
byte 12845056.
In a 20Gb filesystem I had, mounted with the autodefrag option and 20 files of
400Mb each, initially consisting of a single prealloc extent of 400Mb, having
random writes happening at a low rate, lead to a total of over ~17Gb of data
space used, not far from eventually reaching an ENOSPC state.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
When the defrag flag BTRFS_DEFRAG_RANGE_START_IO is set and compression
enabled, we weren't flushing completely, as writing compressed extents
is a 2 steps process, one to compress the data and another one to write
the compressed data to disk.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
The structure for BTRFS_SET_RECEIVED_IOCTL packs differently on 32-bit
and 64-bit systems. This means that it is impossible to use btrfs
receive on a system with a 64-bit kernel and 32-bit userspace, because
the structure size (and hence the ioctl number) is different.
This patch adds a compatibility structure and ioctl to deal with the
above case.
Signed-off-by: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: Josef Bacik <jbacik@fb.com>
