Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'for-4.18/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fix from Mike Snitzer:
"Fix DM writecache target to allow an optional offset to the start of
the data and metadata area.
This allows userspace tools (e.g. LVM2) to place a header and metadata
at the front of the writecache device for its use"
* tag 'for-4.18/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm writecache: support optional offset for start of device
+31
-14
+2
Documentation/device-mapper/writecache.txt
+2
Documentation/device-mapper/writecache.txt
···
15
15
size)
16
16
5. the number of optional parameters (the parameters with an argument
17
17
count as two)
18
+
start_sector n (default: 0)
19
+
offset from the start of cache device in 512-byte sectors
18
20
high_watermark n (default: 50)
19
21
start writeback when the number of used blocks reach this
20
22
watermark
+29
-14
drivers/md/dm-writecache.c
+29
-14
drivers/md/dm-writecache.c
···
136
136
struct dm_target *ti;
137
137
struct dm_dev *dev;
138
138
struct dm_dev *ssd_dev;
139
+
sector_t start_sector;
139
140
void *memory_map;
140
141
uint64_t memory_map_size;
141
142
size_t metadata_sectors;
···
294
293
}
295
294
296
295
dax_read_unlock(id);
296
+
297
+
wc->memory_map += (size_t)wc->start_sector << SECTOR_SHIFT;
298
+
wc->memory_map_size -= (size_t)wc->start_sector << SECTOR_SHIFT;
299
+
297
300
return 0;
298
301
err3:
299
302
kvfree(pages);
···
316
311
static void persistent_memory_release(struct dm_writecache *wc)
317
312
{
318
313
if (wc->memory_vmapped)
319
-
vunmap(wc->memory_map);
314
+
vunmap(wc->memory_map - ((size_t)wc->start_sector << SECTOR_SHIFT));
320
315
}
321
316
322
317
static struct page *persistent_memory_page(void *addr)
···
364
359
365
360
static sector_t cache_sector(struct dm_writecache *wc, struct wc_entry *e)
366
361
{
367
-
return wc->metadata_sectors +
362
+
return wc->start_sector + wc->metadata_sectors +
368
363
((sector_t)e->index << (wc->block_size_bits - SECTOR_SHIFT));
369
364
}
370
365
···
476
471
if (unlikely(region.sector + region.count > wc->metadata_sectors))
477
472
region.count = wc->metadata_sectors - region.sector;
478
473
474
+
region.sector += wc->start_sector;
479
475
atomic_inc(&endio.count);
480
476
req.bi_op = REQ_OP_WRITE;
481
477
req.bi_op_flags = REQ_SYNC;
···
1952
1946
}
1953
1947
wc->memory_map_size = i_size_read(wc->ssd_dev->bdev->bd_inode);
1954
1948
1955
-
if (WC_MODE_PMEM(wc)) {
1956
-
r = persistent_memory_claim(wc);
1957
-
if (r) {
1958
-
ti->error = "Unable to map persistent memory for cache";
1959
-
goto bad;
1960
-
}
1961
-
}
1962
-
1963
1949
/*
1964
1950
* Parse the cache block size
1965
1951
*/
···
1980
1982
1981
1983
while (opt_params) {
1982
1984
string = dm_shift_arg(&as), opt_params--;
1983
-
if (!strcasecmp(string, "high_watermark") && opt_params >= 1) {
1985
+
if (!strcasecmp(string, "start_sector") && opt_params >= 1) {
1986
+
unsigned long long start_sector;
1987
+
string = dm_shift_arg(&as), opt_params--;
1988
+
if (sscanf(string, "%llu%c", &start_sector, &dummy) != 1)
1989
+
goto invalid_optional;
1990
+
wc->start_sector = start_sector;
1991
+
if (wc->start_sector != start_sector ||
1992
+
wc->start_sector >= wc->memory_map_size >> SECTOR_SHIFT)
1993
+
goto invalid_optional;
1994
+
} else if (!strcasecmp(string, "high_watermark") && opt_params >= 1) {
1984
1995
string = dm_shift_arg(&as), opt_params--;
1985
1996
if (sscanf(string, "%d%c", &high_wm_percent, &dummy) != 1)
1986
1997
goto invalid_optional;
···
2046
2039
goto bad;
2047
2040
}
2048
2041
2049
-
if (!WC_MODE_PMEM(wc)) {
2042
+
if (WC_MODE_PMEM(wc)) {
2043
+
r = persistent_memory_claim(wc);
2044
+
if (r) {
2045
+
ti->error = "Unable to map persistent memory for cache";
2046
+
goto bad;
2047
+
}
2048
+
} else {
2050
2049
struct dm_io_region region;
2051
2050
struct dm_io_request req;
2052
2051
size_t n_blocks, n_metadata_blocks;
2053
2052
uint64_t n_bitmap_bits;
2053
+
2054
+
wc->memory_map_size -= (uint64_t)wc->start_sector << SECTOR_SHIFT;
2054
2055
2055
2056
bio_list_init(&wc->flush_list);
2056
2057
wc->flush_thread = kthread_create(writecache_flush_thread, wc, "dm_writecache_flush");
···
2112
2097
}
2113
2098
2114
2099
region.bdev = wc->ssd_dev->bdev;
2115
-
region.sector = 0;
2100
+
region.sector = wc->start_sector;
2116
2101
region.count = wc->metadata_sectors;
2117
2102
req.bi_op = REQ_OP_READ;
2118
2103
req.bi_op_flags = REQ_SYNC;
···
2280
2265
2281
2266
static struct target_type writecache_target = {
2282
2267
.name = "writecache",
2283
-
.version = {1, 0, 0},
2268
+
.version = {1, 1, 0},
2284
2269
.module = THIS_MODULE,
2285
2270
.ctr = writecache_ctr,
2286
2271
.dtr = writecache_dtr,