[PATCH 10/21] Btrfs: devid subset filter
From: Ilya Dryomov <idryomov@gmail.com>
Date: 2012-01-06 14:30:58
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
Select chunks which have at least one byte of at least one stripe located on a device with devid X in a given [pstart,pend) physical address range. This filter only works when devid filter is turned on. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> --- fs/btrfs/volumes.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.h | 1 + 2 files changed, 46 insertions(+), 0 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d52cfde..a5a2d65 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c@@ -2167,6 +2167,45 @@ static int chunk_devid_filter(struct extent_buffer *leaf, return 1; } +/* [pstart, pend) */ +static int chunk_drange_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + u64 stripe_offset; + u64 stripe_length; + int factor; + int i; + + BUG_ON(!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID)); + + if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) + factor = 2; + else + factor = 1; + factor = num_stripes / factor; + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) != bargs->devid) + continue; + + stripe_offset = btrfs_stripe_offset(leaf, stripe); + stripe_length = btrfs_chunk_length(leaf, chunk); + do_div(stripe_length, factor); + + if (stripe_offset < bargs->pend && + stripe_offset + stripe_length > bargs->pstart) + return 0; + } + + return 1; +} + static int should_balance_chunk(struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2206,6 +2245,12 @@ static int should_balance_chunk(struct btrfs_root *root, return 0; } + /* drange filter, makes sense only with devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) && + chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) { + return 0; + } + return 1; }
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7007a31..75fb5f2 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h@@ -202,6 +202,7 @@ struct map_lookup { #define BTRFS_BALANCE_ARGS_PROFILES (1ULL << 0) #define BTRFS_BALANCE_ARGS_USAGE (1ULL << 1) #define BTRFS_BALANCE_ARGS_DEVID (1ULL << 2) +#define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3) struct btrfs_balance_args; struct btrfs_balance_control {
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1.7.6.3