01 Dec, 2011

10 commits

  • If we don't have a cluster, don't bother trying to allocate from it,
    jumping right away to the attempt to allocate a new cluster.

    Signed-off-by: Alexandre Oliva
    Signed-off-by: Chris Mason

    Alexandre Oliva
     
  • We test whether a block group has enough free space to hold the
    requested block, but when we're doing clustered allocation, we can
    save some cycles by testing whether it has enough room for the cluster
    upfront, otherwise we end up attempting to set up a cluster and
    failing. Only in the NO_EMPTY_SIZE loop do we attempt an unclustered
    allocation, and by then we'll have zeroed the cluster size, so this
    patch won't stop us from using the block group as a last resort.

    Signed-off-by: Alexandre Oliva
    Signed-off-by: Chris Mason

    Alexandre Oliva
     
  • Instead of starting at zero (offset is always zero), request a cluster
    starting at search_start, that denotes the beginning of the current
    block group.

    Signed-off-by: Alexandre Oliva
    Signed-off-by: Chris Mason

    Alexandre Oliva
     
  • The field that indicates the size of the largest contiguous chunk of
    free space in the cluster is not initialized when setting up bitmaps,
    it's only increased when we find a larger contiguous chunk. We end up
    retaining a larger value than appropriate for highly-fragmented
    clusters, which may cause pointless searches for large contiguous
    groups, and even cause clusters that do not meet the density
    requirements to be set up.

    Signed-off-by: Alexandre Oliva
    Signed-off-by: Chris Mason

    Alexandre Oliva
     
  • We're failing to create clusters with bitmaps because
    setup_cluster_no_bitmap checks that the list is empty before inserting
    the bitmap entry in the list for setup_cluster_bitmap, but the list
    field is only initialized when it is restored from the on-disk free
    space cache, or when it is written out to disk.

    Besides a potential race condition due to the multiple use of the list
    field, filesystem performance severely degrades over time: as we use
    up all non-bitmap free extents, the try-to-set-up-cluster dance is
    done at every metadata block allocation. For every block group, we
    fail to set up a cluster, and after failing on them all up to twice,
    we fall back to the much slower unclustered allocation.

    To make matters worse, before the unclustered allocation, we try to
    create new block groups until we reach the 1% threshold, which
    introduces additional bitmaps and thus block groups that we'll iterate
    over at each metadata block request.

    Alexandre Oliva
     
  • To reproduce this bug:

    # dd if=/dev/zero of=img bs=1M count=256
    # mkfs.btrfs img
    # losetup -r /dev/loop1 img
    # mount /dev/loop1 /mnt
    OOPS!!

    It triggered BUG_ON(!nr_devices) in btrfs_calc_avail_data_space().

    To fix this, instead of checking write-only devices, we check all open
    deivces:

    # df -h /dev/loop1
    Filesystem Size Used Avail Use% Mounted on
    /dev/loop1 250M 28K 238M 1% /mnt

    Signed-off-by: Li Zefan

    Li Zefan
     
  • It seems overly harsh to fail a resize of a btrfs file system to the
    same size when a shrink or grow would succeed. User app GParted trips
    over this error. Allow it by bypassing the shrink or grow operation.

    Signed-off-by: Mike Fleetwood

    Mike Fleetwood
     
  • When I ran the xfstests, I found the test tasks was blocked on meta-data
    reservation.

    By debugging, I found the reason of this bug:
    start transaction
    |
    v
    reserve meta-data space
    |
    v
    flush delay allocation -> iput inode -> evict inode
    ^ |
    | v
    wait for delay allocation flush

    Miao Xie
     
  • The location of the btrfs-progs repository has been changed.
    This patch updates the documentation accordingly.

    Signed-off-by: Arnd Hannemann

    Arnd Hannemann
     
  • init_ipath() can return an ERR_PTR(-ENOMEM).

    Signed-off-by: Dan Carpenter

    Dan Carpenter
     

22 Nov, 2011

1 commit

  • The log replay code only partially loads block groups, since
    the block group caching code is able to detect and deal with
    extents the logging code has pinned down.

    While the logging code is pinning down block groups, there is
    a bogus WARN_ON we're hitting if the code wasn't able to find
    an extent in the cache. This commit removes the warning because
    it can happen any time there isn't a valid free space cache
    for that block group.

    Signed-off-by: Chris Mason

    Chris Mason
     

20 Nov, 2011

10 commits

  • We've been hitting BUG()'s in btrfs_cont_expand and btrfs_fallocate and anywhere
    else that calls btrfs_get_extent while running xfstests 13 in a loop. This is
    because fiemap is calling btrfs_get_extent with non-sectorsize aligned offsets,
    which will end up adding mappings that are not sectorsize aligned, which will
    cause problems in some cases for subsequent calls to btrfs_get_extent for
    similar areas that are sectorsize aligned. With this patch I ran xfstests 13 in
    a loop for a couple of hours and didn't hit the problem that I could previously
    hit in at most 20 minutes. Thanks,

    Signed-off-by: Josef Bacik

    Josef Bacik
     
  • When doing the io_ctl helpers to clean up the free space cache stuff I stopped
    using our normal prepare_pages stuff, which means I of course forgot to do
    things like set the pages extent mapped, which will cause us all sorts of
    wonderful propblems. Thanks,

    Signed-off-by: Josef Bacik

    Josef Bacik
     
  • We've been hitting panics when running xfstest 13 in a loop for long periods of
    time. And actually this problem has always existed so we've been hitting these
    things randomly for a while. Basically what happens is we get a thread coming
    into the allocator and reading the space cache off of disk and adding the
    entries to the free space cache as we go. Then we get another thread that comes
    in and tries to allocate from that block group. Since block_group->cached !=
    BTRFS_CACHE_NO it goes ahead and tries to do the allocation. We do this because
    if we're doing the old slow way of caching we don't want to hold people up and
    wait for everything to finish. The problem with this is we could end up
    discarding the space cache at some arbitrary point in the future, which means we
    could very well end up allocating space that is either bad, or when the real
    caching happens it could end up thinking the space isn't in use when it really
    is and cause all sorts of other problems.

    The solution is to add a new flag to indicate we are loading the free space
    cache from disk, and always try to cache the block group if cache->cached !=
    BTRFS_CACHE_FINISHED. That way if we are loading the space cache anybody else
    who tries to allocate from the block group will have to wait until it's finished
    to make sure it completes successfully. Thanks,

    Signed-off-by: Josef Bacik

    Josef Bacik
     
  • For the user it is confusing to find something like:
    [10197.627710] new size for /dev/mapper/vg0-usr_share is 3221225472
    in kernel log, because it doesn't point directly to btrfs.

    This patch prefixes those messages with "btrfs:" like other btrfs
    related printks.

    Signed-off-by: Arnd Hannemann
    Signed-off-by: Chris Mason

    Arnd Hannemann
     
  • Round inode bytes and delalloc bytes up to real blocksize before
    converting to sector size. Otherwise eg. files smaller than 512
    are reported with zero blocks due to incorrect rounding.

    Signed-off-by: David Sterba
    Signed-off-by: Chris Mason

    David Sterba
     
  • setup_cluster_no_bitmap() searches all the extents and bitmaps starting
    from offset. Therefore if it returns -ENOSPC, all the bitmaps starting
    from offset are in the bitmaps list, so it's sufficient to search from
    this list in setup_cluser_bitmap().

    Signed-off-by: Li Zefan
    Signed-off-by: Chris Mason

    Li Zefan
     
  • Suppose there are two bitmaps [0, 256], [256, 512] and one extent
    [100, 120] in the free space cache, and we want to setup a cluster
    with offset=100, bytes=50.

    In this case, there will be only one bitmap [256, 512] in the temporary
    bitmaps list, and then setup_cluster_bitmap() won't search bitmap [0, 256].

    The cause is, the list is constructed in setup_cluster_no_bitmap(),
    and only bitmaps with bitmap_entry->offset >= offset will be added
    into the list, and the very bitmap that convers offset has
    bitmap_entry->offset
    Signed-off-by: Chris Mason

    Li Zefan
     
  • My previous patch introduced some u64 for failed_mirror variables, this one
    makes it consistent again.

    Signed-off-by: Jan Schmidt
    Signed-off-by: Chris Mason

    Jan Schmidt
     
  • This patch casts to unsigned long before casting to a pointer and fixes
    the following warnings:
    fs/btrfs/extent_io.c:2289:20: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
    fs/btrfs/ioctl.c:2933:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
    fs/btrfs/ioctl.c:2937:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    fs/btrfs/ioctl.c:3020:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    fs/btrfs/scrub.c:275:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    fs/btrfs/backref.c:686:27: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

    Signed-off-by: Jeff Mahoney
    Signed-off-by: Chris Mason

    Jeff Mahoney
     
  • When btrfs is writing the super blocks, it send barrier flushes to make
    sure writeback caching drives get all the metadata on disk in the
    right order.

    But, we have two bugs in the way these are sent down. When doing
    full commits (not via the tree log), we are sending the barrier down
    before the last super when it should be going down before the first.

    In multi-device setups, we should be waiting for the barriers to
    complete on all devices before writing any of the supers.

    Both of these bugs can cause corruptions on power failures. We fix it
    with some new code to send down empty barriers to all devices before
    writing the first super.

    Alexandre Oliva found the multi-device bug. Arne Jansen did the async
    barrier loop.

    Signed-off-by: Chris Mason
    Reported-by: Alexandre Oliva

    Chris Mason
     

15 Nov, 2011

1 commit

  • The btrfs snapshotting code requires that once a root has been
    snapshotted, we don't change it during a commit.

    But there are two cases to lead to tree corruptions:

    1) multi-thread snapshots can commit serveral snapshots in a transaction,
    and this may change the src root when processing the following pending
    snapshots, which lead to the former snapshots corruptions;

    2) the free inode cache was changing the roots when it root the cache,
    which lead to corruptions.

    This fixes things by making sure we force COW the block after we create a
    snapshot during commiting a transaction, then any changes to the roots
    will result in COW, and we get all the fs roots and snapshot roots to be
    consistent.

    Signed-off-by: Liu Bo
    Signed-off-by: Miao Xie
    Signed-off-by: Chris Mason

    Liu Bo
     

11 Nov, 2011

11 commits

  • Rename no_space_cache option to nospace_cache to be more consistent with
    the rest, where the simple prefix 'no' is used to negate an option.

    The option has been introduced during the -rc1 cycle and there are has not been
    widely used, so it's safe.

    Signed-off-by: David Sterba
    Signed-off-by: Chris Mason

    David Sterba
     
  • Currently scrub fails with ENOMEM when bio_add_page fails. Unfortunately
    dm based targets accept only one page per bio, thus making scrub always
    fails. This patch just submits the current bio when an error is encountered
    and starts a new one.

    Signed-off-by: Arne Jansen
    Signed-off-by: Chris Mason

    Arne Jansen
     
  • We can not do flushable reservation for the relocation when we create snapshot,
    because it may make the transaction commit task and the flush task wait for
    each other and the deadlock happens.

    Signed-off-by: Miao Xie
    Signed-off-by: Chris Mason

    Miao Xie
     
  • People have been running into a warning when loading space cache because the
    page is already mapped when trying to read in a bitmap. The way we read in
    entries and pages is kind of convoluted, so fix it so that io_ctl_read_entry
    maps the entries if it needs to, and if it hits the end of the page it simply
    unmaps the page. That way we can unconditionally unmap the io_ctl before
    reading in the bitmap and we should stop hitting these warnings. Thanks,

    Signed-off-by: Josef Bacik
    Signed-off-by: Chris Mason

    Josef Bacik
     
  • If the root node of a fs/file tree is in the block group that is
    being relocated, but the others are not in the other block groups.
    when we create a snapshot for this tree between the relocation tree
    creation ends and ->create_reloc_tree is set to 0, Btrfs will create
    some backref nodes that are the lowest nodes of the backrefs cache.
    But we forget to add them into ->leaves list of the backref cache
    and deal with them, and at last, they will triggered BUG_ON().

    kernel BUG at fs/btrfs/relocation.c:239!

    This patch fixes it by adding them into ->leaves list of backref cache.

    Signed-off-by: Miao Xie
    Signed-off-by: Chris Mason

    Miao Xie
     
  • btrfs_block_rsv_add{, _noflush}() have similar code, so abstract that code.

    Signed-off-by: Miao Xie
    Signed-off-by: Chris Mason

    Miao Xie
     
  • When we did stress test for the space relocation, the deadlock happened.
    By debugging, We found it was caused by the carelessness that we forgot
    to unlock the read lock of the extent buffers in btrfs_orphan_cleanup()
    before we end the transaction handle, so the transaction commit task waited
    the task, which called btrfs_orphan_cleanup(), to unlock the extent buffer,
    but that task waited the commit task to end the transaction commit, and
    the deadlock happened. Fix it.

    Signed-ff-by: Miao Xie

    Signed-off-by: Chris Mason

    Miao Xie
     
  • I-node cache forgets to reserve the space when writing out it. And when
    we do some stress test, such as synctest, it will trigger WARN_ON() in
    use_block_rsv().

    WARNING: at fs/btrfs/extent-tree.c:5718 btrfs_alloc_free_block+0xbf/0x281 [btrfs]()
    ...
    Call Trace:
    [] warn_slowpath_common+0x80/0x98
    [] warn_slowpath_null+0x15/0x17
    [] btrfs_alloc_free_block+0xbf/0x281 [btrfs]
    [] ? __set_page_dirty_nobuffers+0xfe/0x108
    [] __btrfs_cow_block+0x118/0x3b5 [btrfs]
    [] btrfs_cow_block+0x103/0x14e [btrfs]
    [] btrfs_search_slot+0x249/0x6a4 [btrfs]
    [] btrfs_lookup_inode+0x2a/0x8a [btrfs]
    [] btrfs_update_inode+0xaa/0x141 [btrfs]
    [] btrfs_save_ino_cache+0xea/0x202 [btrfs]
    [] ? btrfs_update_reloc_root+0x17e/0x197 [btrfs]
    [] commit_fs_roots+0xaa/0x158 [btrfs]
    [] btrfs_commit_transaction+0x405/0x731 [btrfs]
    [] ? wake_up_bit+0x25/0x25
    [] ? btrfs_log_dentry_safe+0x43/0x51 [btrfs]
    [] btrfs_sync_file+0x16a/0x198 [btrfs]
    [] ? mntput+0x21/0x23
    [] vfs_fsync_range+0x18/0x21
    [] vfs_fsync+0x17/0x19
    [] do_fsync+0x29/0x3e
    [] sys_fsync+0xb/0xf
    [] system_call_fastpath+0x16/0x1b

    Sometimes it causes BUG_ON() in the reservation code of the delayed inode
    is triggered.

    So we must reserve enough space for inode cache.

    Note: If we can not reserve the enough space for inode cache, we will
    give up writing out it.

    Signed-off-by: Miao Xie
    Signed-off-by: Chris Mason

    Miao Xie
     
  • btrfs_previous_item() just search the b+ tree, do not COW the nodes or leaves,
    if we modify the result of it, the meta-data will be broken. fix it.

    Signed-off-by: Miao Xie
    Signed-off-by: Chris Mason

    Miao Xie
     
  • Chris Mason
     
  • Josef sent along an incremental to the inode reservation
    code to make sure we try and fall back to directly updating
    the inode item if things go horribly wrong.

    This reworks that patch slightly, adding a fallback function
    that will always try to update the inode item directly without
    going through the delayed_inode code.

    Signed-off-by: Chris Mason

    Chris Mason
     

10 Nov, 2011

5 commits

  • Commits 6c41761f and 45ea6095 introduced the possibility of NULL pointer
    dereference on error paths, also we would leave all devices busy and
    leak fs_info with all sub-structures on error when trying to mount an
    already mounted fs to a different directory.

    Fix this by doing all allocations before trying to open any of the
    devices, adjust error path for mount-already-mounted-fs case.

    Signed-off-by: Ilya Dryomov

    Ilya Dryomov
     
  • Fix a bug introduced by 7e662854 where we would leave devices busy on
    certain error paths in open_ctree(). fs_info is guaranteed to be
    non-NULL now so it's safe to dereference it on all error paths.

    Signed-off-by: Ilya Dryomov

    Ilya Dryomov
     
  • Fix bugs introduced by 6c41761f. Firstly, after failing to allocate any
    of the tree roots (first 'goto fail' in open_ctree()) we would
    dereference a NULL fs_info pointer in free_fs_info(). Secondly, after
    failures from init_srcu_struct(), setup_bdi() and new_inode() we would
    leak all earlier allocated roots: fs_info fields haven't been
    initialized yet so free_fs_info() is rendered useless.

    Fix this by initializing fs_info pointer and fs_info fields before any
    allocations happen.

    Signed-off-by: Ilya Dryomov

    Ilya Dryomov
     
  • btrfs_parse_early_options() can fail due to error while scanning devices
    (-o device= option), but still strdup() subvol_name string:

    mount -o subvol=SUBV,device=BAD_DEVICE

    So free subvol_name string on error.

    Signed-off-by: Ilya Dryomov

    Ilya Dryomov
     
  • Don't leak subvol_name string in case multiple subvol= options are
    given. "The lastest option is effective" behavior (consistent with
    subvolid= and subvolrootid= options) is preserved.

    Signed-off-by: Ilya Dryomov

    Ilya Dryomov
     

09 Nov, 2011

2 commits

  • People have been reporting ENOSPC crashes in finish_ordered_io. This is because
    we try to steal from the delalloc block rsv to satisfy a reservation to update
    the inode. The problem with this is we don't explicitly save space for updating
    the inode when doing delalloc. This is kind of a problem and we've gotten away
    with this because way back when we just stole from the delalloc reserve without
    any questions, and this worked out fine because generally speaking the leaf had
    been modified either by the mtime update when we did the original write or
    because we just updated the leaf when we inserted the file extent item, only on
    rare occasions had the leaf not actually been modified, and that was still ok
    because we'd just use a block or two out of the over-reservation that is
    delalloc.

    Then came the delayed inode stuff. This is amazing, except it wants a full
    reservation for updating the inode since it may do it at some point down the
    road after we've written the blocks and we have to recow everything again. This
    worked out because the delayed inode stuff just stole from the global reserve,
    that is until recently when I changed that because it caused other problems.

    So here we are, we're doing everything right and being screwed for it. So take
    an extra reservation for the inode at delalloc reservation time and carry it
    through the life of the delalloc reservation. If we need it we can steal it in
    the delayed inode stuff. If we have already stolen it try and do a normal
    metadata reservation. If that fails try to steal from the delalloc reservation.
    If _that_ fails we'll get a WARN_ON() so I can start thinking of a better way to
    solve this and in the meantime we'll steal from the global reserve.

    With this patch I ran xfstests 13 in a loop for a couple of hours and didn't see
    any problems.

    Signed-off-by: Josef Bacik
    Signed-off-by: Chris Mason

    Josef Bacik
     
  • If we fail to reserve space in the transaction during truncate, we can
    error out with a NULL trans handle. The cleanup code needs an extra
    check to make sure we aren't trying to use the bad handle.

    Signed-off-by: Chris Mason

    Chris Mason