diff options
-rw-r--r-- | drivers/md/dm-snap-persistent.c | 44 |
1 files changed, 34 insertions, 10 deletions
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index 2a3d626a98d9..5d1a97580cb7 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c | |||
@@ -106,6 +106,13 @@ struct pstore { | |||
106 | void *zero_area; | 106 | void *zero_area; |
107 | 107 | ||
108 | /* | 108 | /* |
109 | * An area used for header. The header can be written | ||
110 | * concurrently with metadata (when invalidating the snapshot), | ||
111 | * so it needs a separate buffer. | ||
112 | */ | ||
113 | void *header_area; | ||
114 | |||
115 | /* | ||
109 | * Used to keep track of which metadata area the data in | 116 | * Used to keep track of which metadata area the data in |
110 | * 'chunk' refers to. | 117 | * 'chunk' refers to. |
111 | */ | 118 | */ |
@@ -148,16 +155,27 @@ static int alloc_area(struct pstore *ps) | |||
148 | */ | 155 | */ |
149 | ps->area = vmalloc(len); | 156 | ps->area = vmalloc(len); |
150 | if (!ps->area) | 157 | if (!ps->area) |
151 | return r; | 158 | goto err_area; |
152 | 159 | ||
153 | ps->zero_area = vmalloc(len); | 160 | ps->zero_area = vmalloc(len); |
154 | if (!ps->zero_area) { | 161 | if (!ps->zero_area) |
155 | vfree(ps->area); | 162 | goto err_zero_area; |
156 | return r; | ||
157 | } | ||
158 | memset(ps->zero_area, 0, len); | 163 | memset(ps->zero_area, 0, len); |
159 | 164 | ||
165 | ps->header_area = vmalloc(len); | ||
166 | if (!ps->header_area) | ||
167 | goto err_header_area; | ||
168 | |||
160 | return 0; | 169 | return 0; |
170 | |||
171 | err_header_area: | ||
172 | vfree(ps->zero_area); | ||
173 | |||
174 | err_zero_area: | ||
175 | vfree(ps->area); | ||
176 | |||
177 | err_area: | ||
178 | return r; | ||
161 | } | 179 | } |
162 | 180 | ||
163 | static void free_area(struct pstore *ps) | 181 | static void free_area(struct pstore *ps) |
@@ -169,6 +187,10 @@ static void free_area(struct pstore *ps) | |||
169 | if (ps->zero_area) | 187 | if (ps->zero_area) |
170 | vfree(ps->zero_area); | 188 | vfree(ps->zero_area); |
171 | ps->zero_area = NULL; | 189 | ps->zero_area = NULL; |
190 | |||
191 | if (ps->header_area) | ||
192 | vfree(ps->header_area); | ||
193 | ps->header_area = NULL; | ||
172 | } | 194 | } |
173 | 195 | ||
174 | struct mdata_req { | 196 | struct mdata_req { |
@@ -285,11 +307,11 @@ static int read_header(struct pstore *ps, int *new_snapshot) | |||
285 | if (r) | 307 | if (r) |
286 | return r; | 308 | return r; |
287 | 309 | ||
288 | r = chunk_io(ps, ps->area, 0, READ, 1); | 310 | r = chunk_io(ps, ps->header_area, 0, READ, 1); |
289 | if (r) | 311 | if (r) |
290 | goto bad; | 312 | goto bad; |
291 | 313 | ||
292 | dh = (struct disk_header *) ps->area; | 314 | dh = ps->header_area; |
293 | 315 | ||
294 | if (le32_to_cpu(dh->magic) == 0) { | 316 | if (le32_to_cpu(dh->magic) == 0) { |
295 | *new_snapshot = 1; | 317 | *new_snapshot = 1; |
@@ -339,15 +361,15 @@ static int write_header(struct pstore *ps) | |||
339 | { | 361 | { |
340 | struct disk_header *dh; | 362 | struct disk_header *dh; |
341 | 363 | ||
342 | memset(ps->area, 0, ps->store->chunk_size << SECTOR_SHIFT); | 364 | memset(ps->header_area, 0, ps->store->chunk_size << SECTOR_SHIFT); |
343 | 365 | ||
344 | dh = (struct disk_header *) ps->area; | 366 | dh = ps->header_area; |
345 | dh->magic = cpu_to_le32(SNAP_MAGIC); | 367 | dh->magic = cpu_to_le32(SNAP_MAGIC); |
346 | dh->valid = cpu_to_le32(ps->valid); | 368 | dh->valid = cpu_to_le32(ps->valid); |
347 | dh->version = cpu_to_le32(ps->version); | 369 | dh->version = cpu_to_le32(ps->version); |
348 | dh->chunk_size = cpu_to_le32(ps->store->chunk_size); | 370 | dh->chunk_size = cpu_to_le32(ps->store->chunk_size); |
349 | 371 | ||
350 | return chunk_io(ps, ps->area, 0, WRITE, 1); | 372 | return chunk_io(ps, ps->header_area, 0, WRITE, 1); |
351 | } | 373 | } |
352 | 374 | ||
353 | /* | 375 | /* |
@@ -667,6 +689,8 @@ static int persistent_ctr(struct dm_exception_store *store, | |||
667 | ps->valid = 1; | 689 | ps->valid = 1; |
668 | ps->version = SNAPSHOT_DISK_VERSION; | 690 | ps->version = SNAPSHOT_DISK_VERSION; |
669 | ps->area = NULL; | 691 | ps->area = NULL; |
692 | ps->zero_area = NULL; | ||
693 | ps->header_area = NULL; | ||
670 | ps->next_free = 2; /* skipping the header and first area */ | 694 | ps->next_free = 2; /* skipping the header and first area */ |
671 | ps->current_committed = 0; | 695 | ps->current_committed = 0; |
672 | 696 | ||