[PATCH] dm mirror log: sector size fix

On-disk logs for dm-mirror devices are currently hard-coded to use 512 byte
hard-sector-sizes.  This patch fixes dm-log so it will work with devices with
non-512-byte hard-sector-sizes.

To maintain full compatibility, instead of moving the clean-bits bitset to a
bitset, and enlarges the disk-header buffer to encompass both the header and
the bitset.  The I/O routines for the bitset are removed, and the I/O routines
for the disk-header now also read/write the bitset.

Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index d73779a..ae41628 100644 (file)
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -155,8 +155,6 @@ struct log_c {
 
        struct io_region header_location;
        struct log_header *disk_header;
-
-       struct io_region bits_location;
 };
 
 /*
@@ -240,29 +238,6 @@ static inline int write_header(struct log_c *log)
                             log->disk_header, &ebits);
 }
 
-/*----------------------------------------------------------------
- * Bits IO
- *--------------------------------------------------------------*/
-static int read_bits(struct log_c *log)
-{
-       int r;
-       unsigned long ebits;
-
-       r = dm_io_sync_vm(1, &log->bits_location, READ,
-                         log->clean_bits, &ebits);
-       if (r)
-               return r;
-
-       return 0;
-}
-
-static int write_bits(struct log_c *log)
-{
-       unsigned long ebits;
-       return dm_io_sync_vm(1, &log->bits_location, WRITE,
-                            log->clean_bits, &ebits);
-}
-
 /*----------------------------------------------------------------
  * core log constructor/destructor
  *
@@ -373,9 +348,10 @@ static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
                    unsigned int argc, char **argv)
 {
        int r;
-       size_t size;
+       size_t size, bitset_size;
        struct log_c *lc;
        struct dm_dev *dev;
+       uint32_t *clean_bits;
 
        if (argc < 2 || argc > 3) {
                DMWARN("wrong number of arguments to disk mirror log");
@@ -399,23 +375,26 @@ static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
        /* setup the disk header fields */
        lc->header_location.bdev = lc->log_dev->bdev;
        lc->header_location.sector = 0;
-       lc->header_location.count = 1;
 
-       /*
-        * We can't read less than this amount, even though we'll
-        * not be using most of this space.
-        */
-       lc->disk_header = vmalloc(1 << SECTOR_SHIFT);
+       /* Include both the header and the bitset in one buffer. */
+       bitset_size = lc->bitset_uint32_count * sizeof(uint32_t);
+       size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
+                          ti->limits.hardsect_size);
+       lc->header_location.count = size >> SECTOR_SHIFT;
+
+       lc->disk_header = vmalloc(size);
        if (!lc->disk_header)
                goto bad;
 
-       /* setup the disk bitset fields */
-       lc->bits_location.bdev = lc->log_dev->bdev;
-       lc->bits_location.sector = LOG_OFFSET;
+       /*
+        * Deallocate the clean_bits buffer that was allocated in core_ctr()
+        * and point it at the appropriate place in the disk_header buffer.
+        */
+       clean_bits = lc->clean_bits;
+       lc->clean_bits = (void *)lc->disk_header + (LOG_OFFSET << SECTOR_SHIFT);
+       memcpy(lc->clean_bits, clean_bits, bitset_size);
+       vfree(clean_bits);
 
-       size = dm_round_up(lc->bitset_uint32_count * sizeof(uint32_t),
-                          1 << SECTOR_SHIFT);
-       lc->bits_location.count = size >> SECTOR_SHIFT;
        return 0;
 
  bad:
@@ -429,6 +408,7 @@ static void disk_dtr(struct dirty_log *log)
        struct log_c *lc = (struct log_c *) log->context;
        dm_put_device(lc->ti, lc->log_dev);
        vfree(lc->disk_header);
+       lc->clean_bits = NULL;
        core_dtr(log);
 }
 
@@ -454,11 +434,6 @@ static int disk_resume(struct dirty_log *log)
        if (r)
                return r;
 
-       /* read the bits */
-       r = read_bits(lc);
-       if (r)
-               return r;
-
        /* set or clear any new bits */
        if (lc->sync == NOSYNC)
                for (i = lc->header.nr_regions; i < lc->region_count; i++)
@@ -473,11 +448,6 @@ static int disk_resume(struct dirty_log *log)
        memcpy(lc->sync_bits, lc->clean_bits, size);
        lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 
-       /* write the bits */
-       r = write_bits(lc);
-       if (r)
-               return r;
-
        /* set the correct number of regions in the header */
        lc->header.nr_regions = lc->region_count;
 
@@ -518,7 +488,7 @@ static int disk_flush(struct dirty_log *log)
        if (!lc->touched)
                return 0;
 
-       r = write_bits(lc);
+       r = write_header(lc);
        if (!r)
                lc->touched = 0;
 

diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 346f3a5..84f2ed6 100644 (file)
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1220,7 +1220,7 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
 
 static struct target_type mirror_target = {
        .name    = "mirror",
-       .version = {1, 0, 1},
+       .version = {1, 0, 2},
        .module  = THIS_MODULE,
        .ctr     = mirror_ctr,
        .dtr     = mirror_dtr,