Eric Lee / smarc-fsl-linux-kernel

09 Jan, 2016

1 commit

  • 385277bfb   dm snapshot: fix hung bios when copy error occurs ... Browse Code »

    When there is an error copying a chunk dm-snapshot can incorrectly hold
    associated bios indefinitely, resulting in hung IO.

    The function copy_callback sets pe->error if there was error copying the
    chunk, and then calls complete_exception. complete_exception calls
    pending_complete on error, otherwise it calls commit_exception with
    commit_callback (and commit_callback calls complete_exception).

    The persistent exception store (dm-snap-persistent.c) assumes that calls
    to prepare_exception and commit_exception are paired.
    persistent_prepare_exception increases ps->pending_count and
    persistent_commit_exception decreases it.

    If there is a copy error, persistent_prepare_exception is called but
    persistent_commit_exception is not. This results in the variable
    ps->pending_count never returning to zero and that causes some pending
    exceptions (and their associated bios) to be held forever.

    Fix this by unconditionally calling commit_exception regardless of
    whether the copy was successful. A new "valid" parameter is added to
    commit_exception -- when the copy fails this parameter is set to zero so
    that the chunk that failed to copy (and all following chunks) is not
    recorded in the snapshot store. Also, remove commit_callback now that
    it is merely a wrapper around pending_complete.

    Signed-off-by: Mikulas Patocka
    Signed-off-by: Mike Snitzer
    Cc: stable@vger.kernel.org

    Mikulas Patocka
     

10 Oct, 2015

1 commit

  • b0d3cc011   dm snapshot: add new persistent store option to support overflow ... Browse Code »

    Commit 76c44f6d80 introduced the possibly for "Overflow" to be reported
    by the snapshot device's status. Older userspace (e.g. lvm2) does not
    handle the "Overflow" status response.

    Fix this incompatibility by requiring newer userspace code, that can
    cope with "Overflow", request the persistent store with overflow support
    by using "PO" (Persistent with Overflow) for the snapshot store type.

    Reported-by: Zdenek Kabelac
    Fixes: 76c44f6d80 ("dm snapshot: don't invalidate on-disk image on snapshot write overflow")
    Reviewed-by: Mikulas Patocka
    Signed-off-by: Mike Snitzer

    Mike Snitzer
     

01 Nov, 2011

1 commit

11 Dec, 2009

3 commits

  • fc56f6fbc   dm snapshot: move cow ref from exception store to snap core ... Browse Code »

    Store the reference to the snapshot cow device in the core snapshot
    code instead of each exception store. It can be accessed through the
    new function dm_snap_cow(). Exception stores should each now maintain a
    reference to their parent snapshot struct.

    This is cleaner and makes part of the forthcoming snapshot merge code simpler.

    Signed-off-by: Mike Snitzer
    Signed-off-by: Alasdair G Kergon
    Reviewed-by: Jonathan Brassow
    Cc: Mikulas Patocka

    Mike Snitzer
     
  • 985903bb3   dm snapshot: add allocated metadata to snapshot status ... Browse Code »

    Add number of sectors used by metadata to the end of the snapshot's status
    line.

    Renamed dm_exception_store_type's 'fraction_full' to 'usage'. Renamed
    arguments to be clearer about what is being returned. Also added
    'metadata_sectors'.

    Signed-off-by: Mike Snitzer
    Signed-off-by: Alasdair G Kergon

    Mike Snitzer
     
  • 1d4989c85   dm snapshot: rename dm_snap_exception to dm_exception ... Browse Code »

    The exception structure is not necessarily just a snapshot
    element (especially after we pull it out of dm-snap.c).

    Renaming appropriately.

    Signed-off-by: Jonathan Brassow
    Reviewed-by: Mike Snitzer
    Signed-off-by: Alasdair G Kergon

    Jon Brassow
     

03 Apr, 2009

6 commits

06 Jan, 2009

2 commits