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| author | Joe Thornber <ejt@redhat.com> | 2012-07-27 15:08:15 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2012-07-27 15:08:15 +0100 |
| commit | 310975573ba40ab526b0d76d28225d8d0999d72b (patch) | |
| tree | 3ad362bb4fc0c70662c7337723222df16611f2eb /drivers/md | |
| parent | 4afdd680f7c106e1c87b6dd7af9751c282ecb4b0 (diff) | |
| download | linux-310975573ba40ab526b0d76d28225d8d0999d72b.tar.gz linux-310975573ba40ab526b0d76d28225d8d0999d72b.tar.bz2 linux-310975573ba40ab526b0d76d28225d8d0999d72b.zip | |
dm persistent data: introduce dm_bm_set_read_only
Introduce dm_bm_set_read_only to switch the block manager into a
read-only mode. To be used when dm-thin degrades due to io errors on
the metadata device.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/persistent-data/dm-block-manager.c | 18 | ||||
| -rw-r--r-- | drivers/md/persistent-data/dm-block-manager.h | 13 |
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c index ad1712e802f6..5ba277768d99 100644 --- a/drivers/md/persistent-data/dm-block-manager.c +++ b/drivers/md/persistent-data/dm-block-manager.c @@ -364,6 +364,7 @@ static void dm_block_manager_write_callback(struct dm_buffer *buf) *--------------------------------------------------------------*/ struct dm_block_manager { struct dm_bufio_client *bufio; + bool read_only:1; }; struct dm_block_manager *dm_block_manager_create(struct block_device *bdev, @@ -390,6 +391,8 @@ struct dm_block_manager *dm_block_manager_create(struct block_device *bdev, goto bad; } + bm->read_only = false; + return bm; bad: @@ -481,6 +484,9 @@ int dm_bm_write_lock(struct dm_block_manager *bm, void *p; int r; + if (bm->read_only) + return -EPERM; + p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result); if (unlikely(IS_ERR(p))) return PTR_ERR(p); @@ -547,6 +553,9 @@ int dm_bm_write_lock_zero(struct dm_block_manager *bm, struct buffer_aux *aux; void *p; + if (bm->read_only) + return -EPERM; + p = dm_bufio_new(bm->bufio, b, (struct dm_buffer **) result); if (unlikely(IS_ERR(p))) return PTR_ERR(p); @@ -589,6 +598,9 @@ int dm_bm_flush_and_unlock(struct dm_block_manager *bm, { int r; + if (bm->read_only) + return -EPERM; + r = dm_bufio_write_dirty_buffers(bm->bufio); if (unlikely(r)) { dm_bm_unlock(superblock); @@ -600,6 +612,12 @@ int dm_bm_flush_and_unlock(struct dm_block_manager *bm, return dm_bufio_write_dirty_buffers(bm->bufio); } +void dm_bm_set_read_only(struct dm_block_manager *bm) +{ + bm->read_only = true; +} +EXPORT_SYMBOL_GPL(dm_bm_set_read_only); + u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor) { return crc32c(~(u32) 0, data, len) ^ init_xor; diff --git a/drivers/md/persistent-data/dm-block-manager.h b/drivers/md/persistent-data/dm-block-manager.h index 327885566631..be5bff61be28 100644 --- a/drivers/md/persistent-data/dm-block-manager.h +++ b/drivers/md/persistent-data/dm-block-manager.h @@ -108,6 +108,19 @@ int dm_bm_unlock(struct dm_block *b); int dm_bm_flush_and_unlock(struct dm_block_manager *bm, struct dm_block *superblock); +/* + * Switches the bm to a read only mode. Once read-only mode + * has been entered the following functions will return -EPERM. + * + * dm_bm_write_lock + * dm_bm_write_lock_zero + * dm_bm_flush_and_unlock + * + * Additionally you should not use dm_bm_unlock_move, however no error will + * be returned if you do. + */ +void dm_bm_set_read_only(struct dm_block_manager *bm); + u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor); /*----------------------------------------------------------------*/ |