From 26176e7c2aa923327becdc25b5aca2cb907ac932 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Mon, 26 Nov 2012 09:26:20 +0000 Subject: [PATCH] Btrfs: restructure btrfs_run_defrag_inodes() This patch restructure btrfs_run_defrag_inodes() and make the code of the auto defragment more readable. Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 2 +- fs/btrfs/file.c | 197 +++++++++++++++++++++++++++++------------------------ 3 files changed, 109 insertions(+), 91 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 389c057..6ba56ae 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3510,6 +3510,7 @@ void btrfs_auto_defrag_exit(void); int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, struct inode *inode); int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info); +void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info); int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync); void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, int skip_pinned); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 76b8250..3229531 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3329,7 +3329,7 @@ int close_ctree(struct btrfs_root *root) (atomic_read(&fs_info->defrag_running) == 0)); /* clear out the rbtree of defraggable inodes */ - btrfs_run_defrag_inodes(fs_info); + btrfs_cleanup_defrag_inodes(fs_info); if (!(fs_info->sb->s_flags & MS_RDONLY)) { ret = btrfs_commit_super(root); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 0091832..3c6f747 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -216,11 +216,11 @@ out: } /* - * must be called with the defrag_inodes lock held + * pick the defragable inode that we want, if it doesn't exist, we will get + * the next one. */ -struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, - u64 root, u64 ino, - struct rb_node **next) +static struct inode_defrag * +btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino) { struct inode_defrag *entry = NULL; struct inode_defrag tmp; @@ -231,7 +231,8 @@ struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, tmp.ino = ino; tmp.root = root; - p = info->defrag_inodes.rb_node; + spin_lock(&fs_info->defrag_inodes_lock); + p = fs_info->defrag_inodes.rb_node; while (p) { parent = p; entry = rb_entry(parent, struct inode_defrag, rb_node); @@ -242,52 +243,128 @@ struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, else if (ret > 0) p = parent->rb_right; else - return entry; + goto out; } - if (next) { - while (parent && __compare_inode_defrag(&tmp, entry) > 0) { - parent = rb_next(parent); + if (parent && __compare_inode_defrag(&tmp, entry) > 0) { + parent = rb_next(parent); + if (parent) entry = rb_entry(parent, struct inode_defrag, rb_node); - } - *next = parent; + else + entry = NULL; } - return NULL; +out: + if (entry) + rb_erase(parent, &fs_info->defrag_inodes); + spin_unlock(&fs_info->defrag_inodes_lock); + return entry; } -/* - * run through the list of inodes in the FS that need - * defragging - */ -int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) +void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info) { struct inode_defrag *defrag; + struct rb_node *node; + + spin_lock(&fs_info->defrag_inodes_lock); + node = rb_first(&fs_info->defrag_inodes); + while (node) { + rb_erase(node, &fs_info->defrag_inodes); + defrag = rb_entry(node, struct inode_defrag, rb_node); + kmem_cache_free(btrfs_inode_defrag_cachep, defrag); + + if (need_resched()) { + spin_unlock(&fs_info->defrag_inodes_lock); + cond_resched(); + spin_lock(&fs_info->defrag_inodes_lock); + } + + node = rb_first(&fs_info->defrag_inodes); + } + spin_unlock(&fs_info->defrag_inodes_lock); +} + +#define BTRFS_DEFRAG_BATCH 1024 + +static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info, + struct inode_defrag *defrag) +{ struct btrfs_root *inode_root; struct inode *inode; - struct rb_node *n; struct btrfs_key key; struct btrfs_ioctl_defrag_range_args range; - u64 first_ino = 0; - u64 root_objectid = 0; int num_defrag; - int defrag_batch = 1024; + /* get the inode */ + key.objectid = defrag->root; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + key.offset = (u64)-1; + inode_root = btrfs_read_fs_root_no_name(fs_info, &key); + if (IS_ERR(inode_root)) { + kmem_cache_free(btrfs_inode_defrag_cachep, defrag); + return PTR_ERR(inode_root); + } + + key.objectid = defrag->ino; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + key.offset = 0; + inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL); + if (IS_ERR(inode)) { + kmem_cache_free(btrfs_inode_defrag_cachep, defrag); + return PTR_ERR(inode); + } + + /* do a chunk of defrag */ + clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); memset(&range, 0, sizeof(range)); range.len = (u64)-1; + range.start = defrag->last_offset; + num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid, + BTRFS_DEFRAG_BATCH); + /* + * if we filled the whole defrag batch, there + * must be more work to do. Queue this defrag + * again + */ + if (num_defrag == BTRFS_DEFRAG_BATCH) { + defrag->last_offset = range.start; + btrfs_requeue_inode_defrag(inode, defrag); + } else if (defrag->last_offset && !defrag->cycled) { + /* + * we didn't fill our defrag batch, but + * we didn't start at zero. Make sure we loop + * around to the start of the file. + */ + defrag->last_offset = 0; + defrag->cycled = 1; + btrfs_requeue_inode_defrag(inode, defrag); + } else { + kmem_cache_free(btrfs_inode_defrag_cachep, defrag); + } + + iput(inode); + return 0; +} + +/* + * run through the list of inodes in the FS that need + * defragging + */ +int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) +{ + struct inode_defrag *defrag; + u64 first_ino = 0; + u64 root_objectid = 0; atomic_inc(&fs_info->defrag_running); - spin_lock(&fs_info->defrag_inodes_lock); while(1) { - n = NULL; + if (!__need_auto_defrag(fs_info->tree_root)) + break; /* find an inode to defrag */ - defrag = btrfs_find_defrag_inode(fs_info, root_objectid, - first_ino, &n); + defrag = btrfs_pick_defrag_inode(fs_info, root_objectid, + first_ino); if (!defrag) { - if (n) { - defrag = rb_entry(n, struct inode_defrag, - rb_node); - } else if (root_objectid || first_ino) { + if (root_objectid || first_ino) { root_objectid = 0; first_ino = 0; continue; @@ -296,71 +373,11 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) } } - /* remove it from the rbtree */ first_ino = defrag->ino + 1; root_objectid = defrag->root; - rb_erase(&defrag->rb_node, &fs_info->defrag_inodes); - - if (btrfs_fs_closing(fs_info)) - goto next_free; - spin_unlock(&fs_info->defrag_inodes_lock); - - /* get the inode */ - key.objectid = defrag->root; - btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); - key.offset = (u64)-1; - inode_root = btrfs_read_fs_root_no_name(fs_info, &key); - if (IS_ERR(inode_root)) - goto next; - - key.objectid = defrag->ino; - btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); - key.offset = 0; - - inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL); - if (IS_ERR(inode)) - goto next; - - /* do a chunk of defrag */ - clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); - range.start = defrag->last_offset; - num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid, - defrag_batch); - /* - * if we filled the whole defrag batch, there - * must be more work to do. Queue this defrag - * again - */ - if (num_defrag == defrag_batch) { - defrag->last_offset = range.start; - btrfs_requeue_inode_defrag(inode, defrag); - /* - * we don't want to kfree defrag, we added it back to - * the rbtree - */ - defrag = NULL; - } else if (defrag->last_offset && !defrag->cycled) { - /* - * we didn't fill our defrag batch, but - * we didn't start at zero. Make sure we loop - * around to the start of the file. - */ - defrag->last_offset = 0; - defrag->cycled = 1; - btrfs_requeue_inode_defrag(inode, defrag); - defrag = NULL; - } - - iput(inode); -next: - spin_lock(&fs_info->defrag_inodes_lock); -next_free: - if (defrag) - kmem_cache_free(btrfs_inode_defrag_cachep, defrag); + __btrfs_run_defrag_inode(fs_info, defrag); } - spin_unlock(&fs_info->defrag_inodes_lock); - atomic_dec(&fs_info->defrag_running); /* -- 2.7.4