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path: root/drivers/md/dm-snap-persistent.c
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Diffstat (limited to 'drivers/md/dm-snap-persistent.c')
-rw-r--r--drivers/md/dm-snap-persistent.c88
1 files changed, 53 insertions, 35 deletions
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 6e3fe4f14934..d5b2e08750d5 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -106,6 +106,13 @@ struct pstore {
void *zero_area;
/*
+ * An area used for header. The header can be written
+ * concurrently with metadata (when invalidating the snapshot),
+ * so it needs a separate buffer.
+ */
+ void *header_area;
+
+ /*
* Used to keep track of which metadata area the data in
* 'chunk' refers to.
*/
@@ -148,16 +155,27 @@ static int alloc_area(struct pstore *ps)
*/
ps->area = vmalloc(len);
if (!ps->area)
- return r;
+ goto err_area;
ps->zero_area = vmalloc(len);
- if (!ps->zero_area) {
- vfree(ps->area);
- return r;
- }
+ if (!ps->zero_area)
+ goto err_zero_area;
memset(ps->zero_area, 0, len);
+ ps->header_area = vmalloc(len);
+ if (!ps->header_area)
+ goto err_header_area;
+
return 0;
+
+err_header_area:
+ vfree(ps->zero_area);
+
+err_zero_area:
+ vfree(ps->area);
+
+err_area:
+ return r;
}
static void free_area(struct pstore *ps)
@@ -169,6 +187,10 @@ static void free_area(struct pstore *ps)
if (ps->zero_area)
vfree(ps->zero_area);
ps->zero_area = NULL;
+
+ if (ps->header_area)
+ vfree(ps->header_area);
+ ps->header_area = NULL;
}
struct mdata_req {
@@ -188,7 +210,8 @@ static void do_metadata(struct work_struct *work)
/*
* Read or write a chunk aligned and sized block of data from a device.
*/
-static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
+static int chunk_io(struct pstore *ps, void *area, chunk_t chunk, int rw,
+ int metadata)
{
struct dm_io_region where = {
.bdev = ps->store->cow->bdev,
@@ -198,7 +221,7 @@ static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
struct dm_io_request io_req = {
.bi_rw = rw,
.mem.type = DM_IO_VMA,
- .mem.ptr.vma = ps->area,
+ .mem.ptr.vma = area,
.client = ps->io_client,
.notify.fn = NULL,
};
@@ -240,7 +263,7 @@ static int area_io(struct pstore *ps, int rw)
chunk = area_location(ps, ps->current_area);
- r = chunk_io(ps, chunk, rw, 0);
+ r = chunk_io(ps, ps->area, chunk, rw, 0);
if (r)
return r;
@@ -254,20 +277,7 @@ static void zero_memory_area(struct pstore *ps)
static int zero_disk_area(struct pstore *ps, chunk_t area)
{
- struct dm_io_region where = {
- .bdev = ps->store->cow->bdev,
- .sector = ps->store->chunk_size * area_location(ps, area),
- .count = ps->store->chunk_size,
- };
- struct dm_io_request io_req = {
- .bi_rw = WRITE,
- .mem.type = DM_IO_VMA,
- .mem.ptr.vma = ps->zero_area,
- .client = ps->io_client,
- .notify.fn = NULL,
- };
-
- return dm_io(&io_req, 1, &where, NULL);
+ return chunk_io(ps, ps->zero_area, area_location(ps, area), WRITE, 0);
}
static int read_header(struct pstore *ps, int *new_snapshot)
@@ -276,6 +286,7 @@ static int read_header(struct pstore *ps, int *new_snapshot)
struct disk_header *dh;
chunk_t chunk_size;
int chunk_size_supplied = 1;
+ char *chunk_err;
/*
* Use default chunk size (or hardsect_size, if larger) if none supplied
@@ -297,11 +308,11 @@ static int read_header(struct pstore *ps, int *new_snapshot)
if (r)
return r;
- r = chunk_io(ps, 0, READ, 1);
+ r = chunk_io(ps, ps->header_area, 0, READ, 1);
if (r)
goto bad;
- dh = (struct disk_header *) ps->area;
+ dh = ps->header_area;
if (le32_to_cpu(dh->magic) == 0) {
*new_snapshot = 1;
@@ -319,20 +330,25 @@ static int read_header(struct pstore *ps, int *new_snapshot)
ps->version = le32_to_cpu(dh->version);
chunk_size = le32_to_cpu(dh->chunk_size);
- if (!chunk_size_supplied || ps->store->chunk_size == chunk_size)
+ if (ps->store->chunk_size == chunk_size)
return 0;
- DMWARN("chunk size %llu in device metadata overrides "
- "table chunk size of %llu.",
- (unsigned long long)chunk_size,
- (unsigned long long)ps->store->chunk_size);
+ if (chunk_size_supplied)
+ DMWARN("chunk size %llu in device metadata overrides "
+ "table chunk size of %llu.",
+ (unsigned long long)chunk_size,
+ (unsigned long long)ps->store->chunk_size);
/* We had a bogus chunk_size. Fix stuff up. */
free_area(ps);
- ps->store->chunk_size = chunk_size;
- ps->store->chunk_mask = chunk_size - 1;
- ps->store->chunk_shift = ffs(chunk_size) - 1;
+ r = dm_exception_store_set_chunk_size(ps->store, chunk_size,
+ &chunk_err);
+ if (r) {
+ DMERR("invalid on-disk chunk size %llu: %s.",
+ (unsigned long long)chunk_size, chunk_err);
+ return r;
+ }
r = dm_io_client_resize(sectors_to_pages(ps->store->chunk_size),
ps->io_client);
@@ -351,15 +367,15 @@ static int write_header(struct pstore *ps)
{
struct disk_header *dh;
- memset(ps->area, 0, ps->store->chunk_size << SECTOR_SHIFT);
+ memset(ps->header_area, 0, ps->store->chunk_size << SECTOR_SHIFT);
- dh = (struct disk_header *) ps->area;
+ dh = ps->header_area;
dh->magic = cpu_to_le32(SNAP_MAGIC);
dh->valid = cpu_to_le32(ps->valid);
dh->version = cpu_to_le32(ps->version);
dh->chunk_size = cpu_to_le32(ps->store->chunk_size);
- return chunk_io(ps, 0, WRITE, 1);
+ return chunk_io(ps, ps->header_area, 0, WRITE, 1);
}
/*
@@ -679,6 +695,8 @@ static int persistent_ctr(struct dm_exception_store *store,
ps->valid = 1;
ps->version = SNAPSHOT_DISK_VERSION;
ps->area = NULL;
+ ps->zero_area = NULL;
+ ps->header_area = NULL;
ps->next_free = 2; /* skipping the header and first area */
ps->current_committed = 0;