#include "locking.h"
#include "compat.h"
+/*
+ * when auto defrag is enabled we
+ * queue up these defrag structs to remember which
+ * inodes need defragging passes
+ */
+struct inode_defrag {
+ struct rb_node rb_node;
+ /* objectid */
+ u64 ino;
+ /*
+ * transid where the defrag was added, we search for
+ * extents newer than this
+ */
+ u64 transid;
+
+ /* root objectid */
+ u64 root;
+
+ /* last offset we were able to defrag */
+ u64 last_offset;
+
+ /* if we've wrapped around back to zero once already */
+ int cycled;
+};
+
+/* pop a record for an inode into the defrag tree. The lock
+ * must be held already
+ *
+ * If you're inserting a record for an older transid than an
+ * existing record, the transid already in the tree is lowered
+ *
+ * If an existing record is found the defrag item you
+ * pass in is freed
+ */
+static int __btrfs_add_inode_defrag(struct inode *inode,
+ struct inode_defrag *defrag)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct inode_defrag *entry;
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+
+ p = &root->fs_info->defrag_inodes.rb_node;
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct inode_defrag, rb_node);
+
+ if (defrag->ino < entry->ino)
+ p = &parent->rb_left;
+ else if (defrag->ino > entry->ino)
+ p = &parent->rb_right;
+ else {
+ /* if we're reinserting an entry for
+ * an old defrag run, make sure to
+ * lower the transid of our existing record
+ */
+ if (defrag->transid < entry->transid)
+ entry->transid = defrag->transid;
+ if (defrag->last_offset > entry->last_offset)
+ entry->last_offset = defrag->last_offset;
+ goto exists;
+ }
+ }
+ BTRFS_I(inode)->in_defrag = 1;
+ rb_link_node(&defrag->rb_node, parent, p);
+ rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
+ return 0;
+
+exists:
+ kfree(defrag);
+ return 0;
+
+}
+
+/*
+ * insert a defrag record for this inode if auto defrag is
+ * enabled
+ */
+int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
+ struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct inode_defrag *defrag;
+ int ret = 0;
+ u64 transid;
+
+ if (!btrfs_test_opt(root, AUTO_DEFRAG))
+ return 0;
+
+ if (root->fs_info->closing)
+ return 0;
+
+ if (BTRFS_I(inode)->in_defrag)
+ return 0;
+
+ if (trans)
+ transid = trans->transid;
+ else
+ transid = BTRFS_I(inode)->root->last_trans;
+
+ defrag = kzalloc(sizeof(*defrag), GFP_NOFS);
+ if (!defrag)
+ return -ENOMEM;
+
+ defrag->ino = inode->i_ino;
+ defrag->transid = transid;
+ defrag->root = root->root_key.objectid;
+
+ spin_lock(&root->fs_info->defrag_inodes_lock);
+ if (!BTRFS_I(inode)->in_defrag)
+ ret = __btrfs_add_inode_defrag(inode, defrag);
+ spin_unlock(&root->fs_info->defrag_inodes_lock);
+ return ret;
+}
+
+/*
+ * must be called with the defrag_inodes lock held
+ */
+struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, u64 ino,
+ struct rb_node **next)
+{
+ struct inode_defrag *entry = NULL;
+ struct rb_node *p;
+ struct rb_node *parent = NULL;
+
+ p = info->defrag_inodes.rb_node;
+ while (p) {
+ parent = p;
+ entry = rb_entry(parent, struct inode_defrag, rb_node);
+
+ if (ino < entry->ino)
+ p = parent->rb_left;
+ else if (ino > entry->ino)
+ p = parent->rb_right;
+ else
+ return entry;
+ }
+
+ if (next) {
+ while (parent && ino > entry->ino) {
+ parent = rb_next(parent);
+ entry = rb_entry(parent, struct inode_defrag, rb_node);
+ }
+ *next = parent;
+ }
+ return NULL;
+}
+
+/*
+ * 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;
+ 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;
+ int num_defrag;
+ int defrag_batch = 1024;
+
+ memset(&range, 0, sizeof(range));
+ range.len = (u64)-1;
+
+ atomic_inc(&fs_info->defrag_running);
+ spin_lock(&fs_info->defrag_inodes_lock);
+ while(1) {
+ n = NULL;
+
+ /* find an inode to defrag */
+ defrag = btrfs_find_defrag_inode(fs_info, first_ino, &n);
+ if (!defrag) {
+ if (n)
+ defrag = rb_entry(n, struct inode_defrag, rb_node);
+ else if (first_ino) {
+ first_ino = 0;
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ /* remove it from the rbtree */
+ first_ino = defrag->ino + 1;
+ rb_erase(&defrag->rb_node, &fs_info->defrag_inodes);
+
+ if (fs_info->closing)
+ 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 */
+ BTRFS_I(inode)->in_defrag = 0;
+ 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_add_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_add_inode_defrag(inode, defrag);
+ defrag = NULL;
+ }
+
+ iput(inode);
+next:
+ spin_lock(&fs_info->defrag_inodes_lock);
+next_free:
+ kfree(defrag);
+ }
+ spin_unlock(&fs_info->defrag_inodes_lock);
+
+ atomic_dec(&fs_info->defrag_running);
+
+ /*
+ * during unmount, we use the transaction_wait queue to
+ * wait for the defragger to stop
+ */
+ wake_up(&fs_info->transaction_wait);
+ return 0;
+}
/* simple helper to fault in pages and copy. This should go away
* and be replaced with calls into generic code.
projects / deliverable / linux.git / blobdiff