Merge tag 'dm-3.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper updates from Alasdair G Kergon:
- Flip the thin target into new read-only or failed modes if errors
  are detected;
- Handle chunk sizes that are not powers of two in the snapshot and
  thin targets;
- Provide a way for userspace to avoid replacing an already-loaded
  multipath hardware handler while booting;
- Reduce dm_thin_endio_hook slab size to avoid allocation failures;
- Numerous small changes and cleanups to the code.

* tag 'dm-3.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (63 commits)
  dm thin: commit before gathering status
  dm thin: add read only and fail io modes
  dm thin metadata: introduce dm_pool_abort_metadata
  dm thin metadata: introduce dm_pool_metadata_set_read_only
  dm persistent data: introduce dm_bm_set_read_only
  dm thin: reduce number of metadata commits
  dm thin metadata: add dm_thin_changed_this_transaction
  dm thin metadata: add format option to dm_pool_metadata_open
  dm thin metadata: tidy up open and format error paths
  dm thin metadata: only check incompat features on open
  dm thin metadata: remove duplicate pmd initialisation
  dm thin metadata: remove create parameter from __create_persistent_data_objects
  dm thin metadata: move __superblock_all_zeroes to __open_or_format_metadata
  dm thin metadata: remove nr_blocks arg from __create_persistent_data_objects
  dm thin metadata: split __open or format metadata
  dm thin metadata: use struct dm_pool_metadata members in __open_or_format_metadata
  dm thin metadata: zero unused superblock uuid
  dm thin metadata: lift __begin_transaction out of __write_initial_superblock
  dm thin metadata: move dm_commit_pool_metadata into __write_initial_superblock
  dm thin metadata: factor out __write_initial_superblock
  ...

2 files changed, 26 insertions, 9 deletions

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 98f34b886f95..38d27a10aa5d 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -66,14 +66,13 @@ typedef int (*dm_request_endio_fn) (struct dm_target *ti,
                                     struct request *clone, int error,
                                     union map_info *map_context);
 
-typedef void (*dm_flush_fn) (struct dm_target *ti);
 typedef void (*dm_presuspend_fn) (struct dm_target *ti);
 typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
 typedef int (*dm_preresume_fn) (struct dm_target *ti);
 typedef void (*dm_resume_fn) (struct dm_target *ti);
 
 typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
-                             char *result, unsigned int maxlen);
+                             unsigned status_flags, char *result, unsigned maxlen);
 
 typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
 
@@ -139,7 +138,6 @@ struct target_type {
         dm_map_request_fn map_rq;
         dm_endio_fn end_io;
         dm_request_endio_fn rq_end_io;
-        dm_flush_fn flush;
         dm_presuspend_fn presuspend;
         dm_postsuspend_fn postsuspend;
         dm_preresume_fn preresume;
@@ -188,8 +186,8 @@ struct dm_target {
         sector_t begin;
         sector_t len;
 
-        /* Always a power of 2 */
-        sector_t split_io;
+        /* If non-zero, maximum size of I/O submitted to a target. */
+        uint32_t max_io_len;
 
         /*
          * A number of zero-length barrier requests that will be submitted
@@ -214,15 +212,27 @@ struct dm_target {
         char *error;
 
         /*
+         * Set if this target needs to receive flushes regardless of
+         * whether or not its underlying devices have support.
+         */
+        bool flush_supported:1;
+
+        /*
          * Set if this target needs to receive discards regardless of
          * whether or not its underlying devices have support.
          */
-        unsigned discards_supported:1;
+        bool discards_supported:1;
+
+        /*
+         * Set if the target required discard request to be split
+         * on max_io_len boundary.
+         */
+        bool split_discard_requests:1;
 
         /*
          * Set if this target does not return zeroes on discarded blocks.
          */
-        unsigned discard_zeroes_data_unsupported:1;
+        bool discard_zeroes_data_unsupported:1;
 };
 
 /* Each target can link one of these into the table */
@@ -360,6 +370,11 @@ void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callback
 int dm_table_complete(struct dm_table *t);
 
 /*
+ * Target may require that it is never sent I/O larger than len.
+ */
+int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len);
+
+/*
  * Table reference counting.
  */
 struct dm_table *dm_get_live_table(struct mapped_device *md);
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 75fd5573516e..91e3a360f611 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -267,9 +267,9 @@ enum {
 #define DM_DEV_SET_GEOMETRY     _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 
 #define DM_VERSION_MAJOR        4
-#define DM_VERSION_MINOR        22
+#define DM_VERSION_MINOR        23
 #define DM_VERSION_PATCHLEVEL   0
-#define DM_VERSION_EXTRA        "-ioctl (2011-10-19)"
+#define DM_VERSION_EXTRA        "-ioctl (2012-07-25)"
 
 /* Status bits */
 #define DM_READONLY_FLAG        (1 << 0) /* In/Out */
@@ -307,6 +307,8 @@ enum {
 
 /*
  * Set this to suspend without flushing queued ios.
+ * Also disables flushing uncommitted changes in the thin target before
+ * generating statistics for DM_TABLE_STATUS and DM_DEV_WAIT.
  */
 #define DM_NOFLUSH_FLAG         (1 << 11) /* In */