20 Nov, 2011

3 commits

  • 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
     

08 Nov, 2011

1 commit

  • On error path 'tree_root' is treed in 'free_fs_info()'.
    No need to free it explicitely. Noticed by SLUB in debug mode:

    Complete reproducer under usermode linux (discovered on real
    machine):

    bdev=/dev/ubda
    btr_root=/btr
    /mkfs.btrfs $bdev
    mount $bdev $btr_root
    mkdir $btr_root/subvols/
    cd $btr_root/subvols/
    /btrfs su cr foo
    /btrfs su cr bar
    mount $bdev -osubvol=subvols/foo $btr_root/subvols/bar
    umount $btr_root/subvols/bar

    which gives

    device fsid 4d55aa28-45b1-474b-b4ec-da912322195e devid 1 transid 7 /dev/ubda
    =============================================================================
    BUG kmalloc-2048: Object already free
    -----------------------------------------------------------------------------

    INFO: Allocated in btrfs_mount+0x389/0x7f0 age=0 cpu=0 pid=277
    INFO: Freed in btrfs_mount+0x51c/0x7f0 age=0 cpu=0 pid=277
    INFO: Slab 0x0000000062886200 objects=15 used=9 fp=0x0000000070b4d2d0 flags=0x4081
    INFO: Object 0x0000000070b4d2d0 @offset=21200 fp=0x0000000070b4a968
    ...
    Call Trace:
    70b31948: [] print_trailer+0xe2/0x130
    70b31978: [] object_err+0x3a/0x50
    70b319a8: [] free_debug_processing+0x142/0x2a0
    70b319e0: [] btrfs_mount+0x55f/0x7f0
    70b319f8: [] __slab_free+0x221/0x2d0

    Signed-off-by: Sergei Trofimovich
    Cc: Arne Jansen
    Cc: Chris Mason
    Cc: David Sterba
    Signed-off-by: Chris Mason

    slyich@gmail.com
     

07 Nov, 2011

1 commit


06 Nov, 2011

16 commits

  • While we're allocating ram for a new transaction, we drop our spinlock.
    When we get the lock back, we do check to see if a transaction started
    while we slept, but we don't check to make sure it isn't blocked
    because a commit has already started.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • In case we were able to map less than we wanted (length < PAGE_SIZE
    clause is true) btrfs_bio is still allocated and we have to free it.

    Signed-off-by: Ilya Dryomov
    Signed-off-by: Chris Mason

    Ilya Dryomov
     
  • Signed-off-by: Chris Mason

    Ilya Dryomov
     
  • Signed-off-by: Chris Mason

    Ilya Dryomov
     
  • If we don't stop them, they linger around corrupting
    memory by using pointers to freed things.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • The scrub readahead branch brought in a new error handling hook,
    but it was leaking extent_buffer references.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • The new ioctls to follow backrefs are not clean for 32/64 bit
    compat. This reworks them for u64s everywhere. They are brand new, so
    there are no problems with changing the interface now.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • Conflicts:
    fs/btrfs/Makefile
    fs/btrfs/extent_io.c
    fs/btrfs/extent_io.h
    fs/btrfs/scrub.c

    Signed-off-by: Chris Mason

    Chris Mason
     
  • Conflicts:
    fs/btrfs/ctree.h

    Signed-off-by: Chris Mason

    Chris Mason
     
  • We all keep getting those stupid warnings from use_block_rsv when running
    stress.sh, and it's because the delayed insertion stuff is being stupid. It's
    not the delayed insertion stuffs fault, it's all just stupid. When marking an
    inode dirty for oh say updating the time on it, we just do a
    btrfs_join_transaction, which doesn't reserve any space. This is stupid because
    we're going to have to have space reserve to make this change, but we do it
    because it's fast because chances are we're going to call it over and over again
    and it doesn't matter. Well thanks to the delayed insertion stuff this is
    mostly the case, so we do actually need to make this reservation. So if
    trans->bytes_reserved is 0 then try to do a normal reservation. If not return
    ENOSPC which will make the btrfs_dirty_inode start a proper transaction which
    will let it do the whole ENOSPC dance and reserve enough space for the delayed
    insertion to steal the reservation from the transaction.

    The other stupid thing we do is not reserve space for the inode when writing to
    the thing. Usually this is ok since we have to update the time so we'd have
    already done all this work before we get to the endio stuff, so it doesn't
    matter. But this is stupid because we could write the data after the
    transaction commits where we changed the mtime of the inode so we have to cow
    all the way down to the inode anyway. This used to be masked by the delalloc
    reservation stuff, but because we delay the update it doesn't get masked in this
    case. So again the delayed insertion stuff bites us in the ass. So if our
    trans->block_rsv is delalloc, just steal the reservation from the delalloc
    reserve. Hopefully this won't bite us in the ass, but I've said that before.

    With this patch stress.sh no longer spits out those stupid warnings (famous last
    words). Thanks,

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

    Josef Bacik
     
  • Failure testing was tripping up over stale PageError bits in
    metadata pages. If we have an io error on a block, and later on
    end up reusing it, nobody ever clears PageError on those pages.

    During commit, we'll find PageError and think we had trouble writing
    the block, which will lead to aborts and other problems.

    This changes clean_tree_block and the btrfs writepage code to
    clear the PageError bit. In both cases we're either completely
    done with the page or the page has good stuff and the error bit
    is no longer valid.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • Because of the overcommit stuff I had to make it so that we committed the
    transaction all the time in reserve_metadata_bytes in case we had overcommitted
    because of delayed items. This was because previously we had no way of knowing
    how much space was reserved for delayed items. Now that we have the
    delayed_block_rsv we can check it to see if committing the transaction would get
    us anywhere. This patch breaks out the committing logic into a helper function
    that will check to see if committing the transaction would free enough space for
    us to get anything done. With this patch xfstests 83 goes from taking 445
    seconds to taking 28 seconds on my box. Thanks,

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

    Josef Bacik
     
  • I've been hitting warnings in use_block_rsv when running the delayed insertion
    stuff. It's because we will readjust global block rsv based on what is in use,
    which means we could end up discarding reservations that are for the delayed
    insertion stuff. So instead create a seperate block rsv for the delayed
    insertion stuff. This will also make it easier to debug problems with the
    delayed insertion reservations since we will know that only the delayed
    insertion code touches this block_rsv. Thanks,

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

    Josef Bacik
     
  • This takes some of the free space in the btrfs super block
    to record information about most of the roots in the last four
    commits.

    It also adds a -o recovery to use the root history log when
    we're not able to read the tree of tree roots, the extent
    tree root, the device tree root or the csum root.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • fs_info has now ~9kb, more than fits into one page. This will cause
    mount failure when memory is too fragmented. Top space consumers are
    super block structures super_copy and super_for_commit, ~2.8kb each.
    Allocate them dynamically. fs_info will be ~3.5kb. (measured on x86_64)

    Add a wrapper for freeing fs_info and all of it's dynamically allocated
    members.

    Signed-off-by: David Sterba

    David Sterba
     
  • We no longer use the orphan block rsv for holding the reservation for truncating
    the inode, so instead use the global block rsv and check to make sure it has
    enough space for us to truncate the space. Thanks,

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

    Josef Bacik