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author | Paul Clements <paul.clements@steeleye.com> | 2006-10-03 01:15:49 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-03 08:04:17 -0700 |
commit | 9b1d1dac181d8c1b9492e05cee660a985d035a06 (patch) | |
tree | af12b1eaac4e0f7f3528ec26a223faeabed35845 /drivers/md | |
parent | 76186dd8b73d2b7b9b4c8629b89c845e97009801 (diff) | |
download | kernel_samsung_espresso10-9b1d1dac181d8c1b9492e05cee660a985d035a06.zip kernel_samsung_espresso10-9b1d1dac181d8c1b9492e05cee660a985d035a06.tar.gz kernel_samsung_espresso10-9b1d1dac181d8c1b9492e05cee660a985d035a06.tar.bz2 |
[PATCH] md: new sysfs interface for setting bits in the write-intent-bitmap
Add a new sysfs interface that allows the bitmap of an array to be dirtied.
The interface is write-only, and is used as follows:
echo "1000" > /sys/block/md2/md/bitmap
(dirty the bit for chunk 1000 [offset 0] in the in-memory and on-disk
bitmaps of array md2)
echo "1000-2000" > /sys/block/md1/md/bitmap
(dirty the bits for chunks 1000-2000 in md1's bitmap)
This is useful, for example, in cluster environments where you may need to
combine two disjoint bitmaps into one (following a server failure, after a
secondary server has taken over the array). By combining the bitmaps on
the two servers, a full resync can be avoided (This was discussed on the
list back on March 18, 2005, "[PATCH 1/2] md bitmap bug fixes" thread).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/bitmap.c | 14 | ||||
-rw-r--r-- | drivers/md/md.c | 31 |
2 files changed, 45 insertions, 0 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index ecc5676..0a44298 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -613,6 +613,7 @@ static inline unsigned long file_page_offset(unsigned long chunk) static inline struct page *filemap_get_page(struct bitmap *bitmap, unsigned long chunk) { + if (file_page_index(chunk) >= bitmap->file_pages) return NULL; return bitmap->filemap[file_page_index(chunk) - file_page_index(0)]; } @@ -739,6 +740,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block) } page = filemap_get_page(bitmap, chunk); + if (!page) return; bit = file_page_offset(chunk); /* set the bit */ @@ -1322,6 +1324,18 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int n } +/* dirty the memory and file bits for bitmap chunks "s" to "e" */ +void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e) +{ + unsigned long chunk; + + for (chunk = s; chunk <= e; chunk++) { + sector_t sec = chunk << CHUNK_BLOCK_SHIFT(bitmap); + bitmap_set_memory_bits(bitmap, sec, 1); + bitmap_file_set_bit(bitmap, sec); + } +} + /* * flush out any pending updates */ diff --git a/drivers/md/md.c b/drivers/md/md.c index 8b08043..b95dd8a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2524,6 +2524,36 @@ static struct md_sysfs_entry md_new_device = __ATTR(new_dev, S_IWUSR, null_show, new_dev_store); static ssize_t +bitmap_store(mddev_t *mddev, const char *buf, size_t len) +{ + char *end; + unsigned long chunk, end_chunk; + + if (!mddev->bitmap) + goto out; + /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */ + while (*buf) { + chunk = end_chunk = simple_strtoul(buf, &end, 0); + if (buf == end) break; + if (*end == '-') { /* range */ + buf = end + 1; + end_chunk = simple_strtoul(buf, &end, 0); + if (buf == end) break; + } + if (*end && !isspace(*end)) break; + bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk); + buf = end; + while (isspace(*buf)) buf++; + } + bitmap_unplug(mddev->bitmap); /* flush the bits to disk */ +out: + return len; +} + +static struct md_sysfs_entry md_bitmap = +__ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store); + +static ssize_t size_show(mddev_t *mddev, char *page) { return sprintf(page, "%llu\n", (unsigned long long)mddev->size); @@ -2843,6 +2873,7 @@ static struct attribute *md_redundancy_attrs[] = { &md_sync_completed.attr, &md_suspend_lo.attr, &md_suspend_hi.attr, + &md_bitmap.attr, NULL, }; static struct attribute_group md_redundancy_group = { |