[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
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -155,8 +155,6 @@
struct io_region header_location;
struct log_header *disk_header;
-
- struct io_region bits_location;
};
/*
@@ -241,29 +239,6 @@
}
/*----------------------------------------------------------------
- * 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
*
* argv contains region_size followed optionally by [no]sync
@@ -373,9 +348,10 @@
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 @@
/* 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 @@
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 @@
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 @@
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 @@
if (!lc->touched)
return 0;
- r = write_bits(lc);
+ r = write_header(lc);
if (!r)
lc->touched = 0;