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author | Stefan Behrens <sbehrens@giantdisaster.de> | 2012-11-06 14:43:46 +0100 |
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committer | Josef Bacik <jbacik@fusionio.com> | 2012-12-12 17:15:43 -0500 |
commit | 472262f35a6b3407e761b700d74c53530e5f144d (patch) | |
tree | 56165ccfa9fe72a9b0e2d455fe023300c0a4b434 /fs/btrfs/volumes.c | |
parent | 29a8d9a0bce6a5abac1f313400c2e189e8d10e67 (diff) | |
download | op-kernel-dev-472262f35a6b3407e761b700d74c53530e5f144d.zip op-kernel-dev-472262f35a6b3407e761b700d74c53530e5f144d.tar.gz |
Btrfs: changes to live filesystem are also written to replacement disk
During a running dev replace operation, all write requests to
the live filesystem are duplicated to also write to the target
drive. Therefore btrfs_map_block() is changed to duplicate
stripes that are written to the source disk of a device replace
procedure to be written to the target disk as well.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs/volumes.c')
-rw-r--r-- | fs/btrfs/volumes.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index de0c05c..4d3bf18 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4044,6 +4044,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, int num_stripes; int max_errors = 0; struct btrfs_bio *bbio = NULL; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + int dev_replace_is_ongoing = 0; + int num_alloc_stripes; read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, logical, *length); @@ -4089,6 +4092,11 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, if (!bbio_ret) goto out; + btrfs_dev_replace_lock(dev_replace); + dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace); + if (!dev_replace_is_ongoing) + btrfs_dev_replace_unlock(dev_replace); + num_stripes = 1; stripe_index = 0; stripe_nr_orig = stripe_nr; @@ -4155,7 +4163,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, } BUG_ON(stripe_index >= map->num_stripes); - bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS); + num_alloc_stripes = num_stripes; + if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD))) + num_alloc_stripes <<= 1; + bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS); if (!bbio) { ret = -ENOMEM; goto out; @@ -4250,11 +4261,48 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, } } + if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) && + dev_replace->tgtdev != NULL) { + int index_where_to_add; + u64 srcdev_devid = dev_replace->srcdev->devid; + + /* + * duplicate the write operations while the dev replace + * procedure is running. Since the copying of the old disk + * to the new disk takes place at run time while the + * filesystem is mounted writable, the regular write + * operations to the old disk have to be duplicated to go + * to the new disk as well. + * Note that device->missing is handled by the caller, and + * that the write to the old disk is already set up in the + * stripes array. + */ + index_where_to_add = num_stripes; + for (i = 0; i < num_stripes; i++) { + if (bbio->stripes[i].dev->devid == srcdev_devid) { + /* write to new disk, too */ + struct btrfs_bio_stripe *new = + bbio->stripes + index_where_to_add; + struct btrfs_bio_stripe *old = + bbio->stripes + i; + + new->physical = old->physical; + new->length = old->length; + new->dev = dev_replace->tgtdev; + index_where_to_add++; + max_errors++; + } + } + num_stripes = index_where_to_add; + } + *bbio_ret = bbio; bbio->num_stripes = num_stripes; bbio->max_errors = max_errors; bbio->mirror_num = mirror_num; out: + if (dev_replace_is_ongoing) + btrfs_dev_replace_unlock(dev_replace); free_extent_map(em); return ret; } |