[PATCH 2/2] Btrfs: make snapshot-aware defrag as a mount option
From: Liu Bo <hidden>
Date: 2012-10-27 10:36:01
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
This feature works on our crucial write endio path, so if we've got lots of fragments to process, it will be kind of a disaster to the performance, so I make such a change. One can benifit from it while mounting with '-o snap_aware_defrag'. Signed-off-by: Liu Bo <redacted> --- fs/btrfs/ctree.h | 1 + fs/btrfs/inode.c | 16 ++++++++++------ fs/btrfs/ioctl.c | 5 +++-- fs/btrfs/super.c | 12 ++++++++++-- 4 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 926c9ff..f9cd9c9 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h@@ -1756,6 +1756,7 @@ struct btrfs_ioctl_defrag_range_args { #define BTRFS_MOUNT_CHECK_INTEGRITY (1 << 20) #define BTRFS_MOUNT_CHECK_INTEGRITY_INCLUDING_EXTENT_DATA (1 << 21) #define BTRFS_MOUNT_PANIC_ON_FATAL_ERROR (1 << 22) +#define BTRFS_MOUNT_SA_DEFRAG (1 << 23) #define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt) #define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 35e6993..069499e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c@@ -2488,13 +2488,17 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) ordered_extent->file_offset + ordered_extent->len - 1, 0, &cached_state); - ret = test_range_bit(io_tree, ordered_extent->file_offset, - ordered_extent->file_offset + ordered_extent->len - 1, - EXTENT_DEFRAG, 1, cached_state); - if (ret && btrfs_root_last_snapshot(&root->root_item) >= + if (btrfs_test_opt(root, SA_DEFRAG)) { + ret = test_range_bit(io_tree, ordered_extent->file_offset, + ordered_extent->file_offset + + ordered_extent->len - 1, + EXTENT_DEFRAG, 1, cached_state); + if (ret && + btrfs_root_last_snapshot(&root->root_item) >= BTRFS_I(inode)->generation) { - /* the inode is shared */ - new = record_old_file_extents(inode, ordered_extent); + /* the inode is shared */ + new = record_old_file_extents(inode, ordered_extent); + } } if (nolock)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 6116880..1367165 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c@@ -1058,8 +1058,9 @@ again: } - set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1, - &cached_state, GFP_NOFS); + if (btrfs_test_opt(BTRFS_I(inode)->root, SA_DEFRAG)) + set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, + page_end - 1, &cached_state, GFP_NOFS); unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end - 1, &cached_state,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 915ac14..24eac5f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c@@ -308,8 +308,8 @@ enum { Opt_compress_type, Opt_compress_force, Opt_compress_force_type, Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, - Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, - Opt_no_space_cache, Opt_recovery, Opt_skip_balance, + Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_sa_defrag, + Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_skip_balance, Opt_check_integrity, Opt_check_integrity_including_extent_data, Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_err,
@@ -344,6 +344,7 @@ static match_table_t tokens = { {Opt_enospc_debug, "enospc_debug"}, {Opt_subvolrootid, "subvolrootid=%d"}, {Opt_defrag, "autodefrag"}, + {Opt_sa_defrag, "snap_aware_defrag"}, {Opt_inode_cache, "inode_cache"}, {Opt_no_space_cache, "nospace_cache"}, {Opt_recovery, "recovery"},
@@ -564,6 +565,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) printk(KERN_INFO "btrfs: enabling auto defrag\n"); btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); break; + case Opt_sa_defrag: + printk(KERN_INFO "btrfs: enabling snapshot-aware" + " defrag\n"); + btrfs_set_opt(info->mount_opt, SA_DEFRAG); + break; case Opt_recovery: printk(KERN_INFO "btrfs: enabling auto recovery\n"); btrfs_set_opt(info->mount_opt, RECOVERY);
@@ -935,6 +941,8 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) seq_puts(seq, ",enospc_debug"); if (btrfs_test_opt(root, AUTO_DEFRAG)) seq_puts(seq, ",autodefrag"); + if (btrfs_test_opt(root, SA_DEFRAG)) + seq_puts(seq, ",snap_aware_defrag"); if (btrfs_test_opt(root, INODE_MAP_CACHE)) seq_puts(seq, ",inode_cache"); if (btrfs_test_opt(root, SKIP_BALANCE))
--
1.7.7.6