1 files changed, 73 insertions, 84 deletions

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index d73779a42417..64b764bd02cc 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -12,6 +12,8 @@
 #include "dm-log.h"
 #include "dm-io.h"
 
+#define DM_MSG_PREFIX "mirror log"
+
 static LIST_HEAD(_log_types);
 static DEFINE_SPINLOCK(_lock);
 
@@ -155,8 +157,6 @@ struct log_c {
 
         struct io_region header_location;
         struct log_header *disk_header;
-
-        struct io_region bits_location;
 };
 
 /*
@@ -241,43 +241,21 @@ static inline int write_header(struct log_c *log)
 }
 
 /*----------------------------------------------------------------
- * 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
  *--------------------------------------------------------------*/
 #define BYTE_SHIFT 3
-static int core_ctr(struct dirty_log *log, struct dm_target *ti,
-                    unsigned int argc, char **argv)
+static int create_log_context(struct dirty_log *log, struct dm_target *ti,
+                              unsigned int argc, char **argv,
+                              struct dm_dev *dev)
 {
         enum sync sync = DEFAULTSYNC;
 
         struct log_c *lc;
         uint32_t region_size;
         unsigned int region_count;
-        size_t bitset_size;
+        size_t bitset_size, buf_size;
 
         if (argc < 1 || argc > 2) {
                 DMWARN("wrong number of arguments to mirror log");
@@ -319,22 +297,53 @@ static int core_ctr(struct dirty_log *log, struct dm_target *ti,
          * Work out how many "unsigned long"s we need to hold the bitset.
          */
         bitset_size = dm_round_up(region_count,
-                                  sizeof(unsigned long) << BYTE_SHIFT);
+                                  sizeof(*lc->clean_bits) << BYTE_SHIFT);
         bitset_size >>= BYTE_SHIFT;
 
-        lc->bitset_uint32_count = bitset_size / 4;
-        lc->clean_bits = vmalloc(bitset_size);
-        if (!lc->clean_bits) {
-                DMWARN("couldn't allocate clean bitset");
-                kfree(lc);
-                return -ENOMEM;
+        lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
+
+        /*
+         * Disk log?
+         */
+        if (!dev) {
+                lc->clean_bits = vmalloc(bitset_size);
+                if (!lc->clean_bits) {
+                        DMWARN("couldn't allocate clean bitset");
+                        kfree(lc);
+                        return -ENOMEM;
+                }
+                lc->disk_header = NULL;
+        } else {
+                lc->log_dev = dev;
+                lc->header_location.bdev = lc->log_dev->bdev;
+                lc->header_location.sector = 0;
+
+                /*
+                 * Buffer holds both header and bitset.
+                 */
+                buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
+                                       bitset_size, ti->limits.hardsect_size);
+                lc->header_location.count = buf_size >> SECTOR_SHIFT;
+
+                lc->disk_header = vmalloc(buf_size);
+                if (!lc->disk_header) {
+                        DMWARN("couldn't allocate disk log buffer");
+                        kfree(lc);
+                        return -ENOMEM;
+                }
+
+                lc->clean_bits = (void *)lc->disk_header +
+                                 (LOG_OFFSET << SECTOR_SHIFT);
         }
+
         memset(lc->clean_bits, -1, bitset_size);
 
         lc->sync_bits = vmalloc(bitset_size);
         if (!lc->sync_bits) {
                 DMWARN("couldn't allocate sync bitset");
-                vfree(lc->clean_bits);
+                if (!dev)
+                        vfree(lc->clean_bits);
+                vfree(lc->disk_header);
                 kfree(lc);
                 return -ENOMEM;
         }
@@ -345,25 +354,40 @@ static int core_ctr(struct dirty_log *log, struct dm_target *ti,
         if (!lc->recovering_bits) {
                 DMWARN("couldn't allocate sync bitset");
                 vfree(lc->sync_bits);
-                vfree(lc->clean_bits);
+                if (!dev)
+                        vfree(lc->clean_bits);
+                vfree(lc->disk_header);
                 kfree(lc);
                 return -ENOMEM;
         }
         memset(lc->recovering_bits, 0, bitset_size);
         lc->sync_search = 0;
         log->context = lc;
+
         return 0;
 }
 
-static void core_dtr(struct dirty_log *log)
+static int core_ctr(struct dirty_log *log, struct dm_target *ti,
+                    unsigned int argc, char **argv)
+{
+        return create_log_context(log, ti, argc, argv, NULL);
+}
+
+static void destroy_log_context(struct log_c *lc)
 {
-        struct log_c *lc = (struct log_c *) log->context;
-        vfree(lc->clean_bits);
         vfree(lc->sync_bits);
         vfree(lc->recovering_bits);
         kfree(lc);
 }
 
+static void core_dtr(struct dirty_log *log)
+{
+        struct log_c *lc = (struct log_c *) log->context;
+
+        vfree(lc->clean_bits);
+        destroy_log_context(lc);
+}
+
 /*----------------------------------------------------------------
  * disk log constructor/destructor
  *
@@ -373,8 +397,6 @@ static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
                     unsigned int argc, char **argv)
 {
         int r;
-        size_t size;
-        struct log_c *lc;
         struct dm_dev *dev;
 
         if (argc < 2 || argc > 3) {
@@ -387,49 +409,22 @@ static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
         if (r)
                 return r;
 
-        r = core_ctr(log, ti, argc - 1, argv + 1);
+        r = create_log_context(log, ti, argc - 1, argv + 1, dev);
         if (r) {
                 dm_put_device(ti, dev);
                 return r;
         }
 
-        lc = (struct log_c *) log->context;
-        lc->log_dev = dev;
-
-        /* 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);
-        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;
-
-        size = dm_round_up(lc->bitset_uint32_count * sizeof(uint32_t),
-                           1 << SECTOR_SHIFT);
-        lc->bits_location.count = size >> SECTOR_SHIFT;
         return 0;
-
- bad:
-        dm_put_device(ti, lc->log_dev);
-        core_dtr(log);
-        return -ENOMEM;
 }
 
 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);
-        core_dtr(log);
+        destroy_log_context(lc);
 }
 
 static int count_bits32(uint32_t *addr, unsigned size)
@@ -454,12 +449,7 @@ 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 */
+        /* set or clear any new bits -- device has grown */
         if (lc->sync == NOSYNC)
                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
                         /* FIXME: amazingly inefficient */
@@ -469,15 +459,14 @@ static int disk_resume(struct dirty_log *log)
                         /* FIXME: amazingly inefficient */
                         log_clear_bit(lc, lc->clean_bits, i);
 
+        /* clear any old bits -- device has shrunk */
+        for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
+                log_clear_bit(lc, lc->clean_bits, i);
+
         /* copy clean across to sync */
         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 +507,7 @@ 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;