Commit a46d11a8 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

Btrfs: add BTRFS_AVAIL_ALLOC_BIT_SINGLE bit 



Right now on-disk BTRFS_BLOCK_GROUP_* profile bits are used for
avail_{data,metadata,system}_alloc_bits fields, which gather info about
available allocation profiles in the FS.  When chunk is created or read
from disk, its profile is OR'ed with the corresponding avail_alloc_bits
field.  Since SINGLE is denoted by 0 in the on-disk format, currently
there is no way to tell when such chunks become avaialble.  Restriper
needs that information, so add a separate bit for SINGLE profile.

This bit is going to be in-memory only, it should never be written out
to disk, so it's not a disk format change.  However to avoid remappings
in future, reserve corresponding on-disk bit.

Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 52ba6929

fs/btrfs/ctree.h

+15 −0
Original line number Diff line number Diff line
@@ -758,6 +758,7 @@ struct btrfs_csum_item { 
#define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)

#define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)

#define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)

#define BTRFS_BLOCK_GROUP_RESERVED	BTRFS_AVAIL_ALLOC_BIT_SINGLE

#define BTRFS_NR_RAID_TYPES		5



#define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
@@ -768,6 +769,15 @@ struct btrfs_csum_item { 
					 BTRFS_BLOCK_GROUP_RAID1 |   \

					 BTRFS_BLOCK_GROUP_DUP |     \

					 BTRFS_BLOCK_GROUP_RAID10)

/*

 * We need a bit for restriper to be able to tell when chunks of type

 * SINGLE are available.  This "extended" profile format is used in

 * fs_info->avail_*_alloc_bits (in-memory) and balance item fields

 * (on-disk).  The corresponding on-disk bit in chunk.type is reserved

 * to avoid remappings between two formats in future.

 */

#define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)



struct btrfs_block_group_item {

	__le64 used;

	__le64 chunk_objectid;
@@ -1140,6 +1150,11 @@ struct btrfs_fs_info { 
	spinlock_t ref_cache_lock;

	u64 total_ref_cache_size;



	/*

	 * these three are in extended format (availability of single

	 * chunks is denoted by BTRFS_AVAIL_ALLOC_BIT_SINGLE bit, other

	 * types are denoted by corresponding BTRFS_BLOCK_GROUP_* bits)

	 */

	u64 avail_data_alloc_bits;

	u64 avail_metadata_alloc_bits;

	u64 avail_system_alloc_bits;

fs/btrfs/extent-tree.c

+21 −9
Original line number Diff line number Diff line
@@ -3014,7 +3014,11 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, 
static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)

{

	u64 extra_flags = flags & BTRFS_BLOCK_GROUP_PROFILE_MASK;

	if (extra_flags) {



	/* chunk -> extended profile */

	if (extra_flags == 0)

		extra_flags = BTRFS_AVAIL_ALLOC_BIT_SINGLE;



	if (flags & BTRFS_BLOCK_GROUP_DATA)

		fs_info->avail_data_alloc_bits |= extra_flags;

	if (flags & BTRFS_BLOCK_GROUP_METADATA)
@@ -3022,8 +3026,12 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) 
	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)

		fs_info->avail_system_alloc_bits |= extra_flags;

}

}



/*

 * @flags: available profiles in extended format (see ctree.h)

 *

 * Returns reduced profile in chunk format.

 */

u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)

{

	/*
@@ -3053,8 +3061,12 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) 
	if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&

	    ((flags & BTRFS_BLOCK_GROUP_RAID1) |

	     (flags & BTRFS_BLOCK_GROUP_RAID10) |

	     (flags & BTRFS_BLOCK_GROUP_DUP)))

	     (flags & BTRFS_BLOCK_GROUP_DUP))) {

		flags &= ~BTRFS_BLOCK_GROUP_RAID0;

	}



	/* extended -> chunk profile */

	flags &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;

	return flags;

}

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