kernel/linux.git/drivers/md/dm-snap-persistent.c, branch linux-4.20.y

dm bufio: move dm-bufio.h to include/linux/

2018-04-03T19:04:23+00:00

Move dm-bufio.h to include/linux/ so that external GPL'd DM target modules can use it. It is better to allow the use of dm-bufio than force external modules to implement the equivalent buffered IO mechanism in some new way. The hope is this will encourage the use of dm-bufio; which will then make it easier for a GPL'd external DM target module to be included upstream. A couple dm-bufio EXPORT_SYMBOL exports have also been updated to use EXPORT_SYMBOL_GPL. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm: make flush bios explicitly sync

2017-05-31T14:50:23+00:00

Commit b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous") removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...} definitions. generic_make_request_checks() however strips REQ_FUA and REQ_PREFLUSH flags from a bio when the storage doesn't report volatile write cache and thus write effectively becomes asynchronous which can lead to performance regressions. Fix the problem by making sure all bios which are synchronous are properly marked with REQ_SYNC. Fixes: b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous") Cc: stable@vger.kernel.org Signed-off-by: Jan Kara Signed-off-by: Mike Snitzer

block,fs: use REQ_* flags directly

2016-11-01T15:43:26+00:00

Remove the WRITE_* and READ_SYNC wrappers, and just use the flags directly. Where applicable this also drops usage of the bio_set_op_attrs wrapper. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

dm: use bio op accessors

2016-06-07T19:41:38+00:00

Separate the op from the rq_flag_bits and have dm set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

dm snapshot: fix hung bios when copy error occurs

2016-01-09T01:03:05+00:00

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

Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2015-11-05T05:19:53+00:00

Pull device mapper updates from Mike Snitzer: "Smaller set of DM changes for this merge. I've based these changes on Jens' for-4.4/reservations branch because the associated DM changes required it. - Revert a dm-multipath change that caused a regression for unprivledged users (e.g. kvm guests) that issued ioctls when a multipath device had no available paths. - Include Christoph's refactoring of DM's ioctl handling and add support for passing through persistent reservations with DM multipath. - All other changes are very simple cleanups" * tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm switch: simplify conditional in alloc_region_table() dm delay: document that offsets are specified in sectors dm delay: capitalize the start of an delay_ctr() error message dm delay: Use DM_MAPIO macros instead of open-coded equivalents dm linear: remove redundant target name from error messages dm persistent data: eliminate unnecessary return values dm: eliminate unused "bioset" process for each bio-based DM device dm: convert ffs to __ffs dm: drop NULL test before kmem_cache_destroy() and mempool_destroy() dm: add support for passing through persistent reservations dm: refactor ioctl handling Revert "dm mpath: fix stalls when handling invalid ioctls" dm: initialize non-blk-mq queue data before queue is used

dm: convert ffs to __ffs

2015-10-31T23:06:01+00:00

ffs counts bit starting with 1 (for the least significant bit), __ffs counts bits starting with 0. This patch changes various occurrences of ffs to __ffs and removes subtraction of 1 from the result. Note that __ffs (unlike ffs) is not defined when called with zero argument, but it is not called with zero argument in any of these cases. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm snapshot persistent: fix missing cleanup in persistent_ctr error path

2015-10-13T16:20:54+00:00

If an unsupported option is given then the early return from persistent_ctr() leaked memory allocated for the 'pstore' and never destroyed the 'metadata_wq'. Fixes: b0d3cc011e53 ("dm snapshot: add new persistent store option to support overflow") Signed-off-by: Sudip Mukherjee Signed-off-by: Mike Snitzer

dm snapshot: add new persistent store option to support overflow

2015-10-09T20:57:03+00:00

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

dm: remove unlikely() before IS_ERR()

2015-08-12T15:32:21+00:00

IS_ERR() already contains an 'unlikely' compiler flag so there is no need to do that again from IS_ERR() callers. Signed-off-by: Viresh Kumar Signed-off-by: Mike Snitzer