#define LOG_INODE_ALL 0
#define LOG_INODE_EXISTS 1
+/*
+ * directory trouble cases
+ *
+ * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
+ * log, we must force a full commit before doing an fsync of the directory
+ * where the unlink was done.
+ * ---> record transid of last unlink/rename per directory
+ *
+ * mkdir foo/some_dir
+ * normal commit
+ * rename foo/some_dir foo2/some_dir
+ * mkdir foo/some_dir
+ * fsync foo/some_dir/some_file
+ *
+ * The fsync above will unlink the original some_dir without recording
+ * it in its new location (foo2). After a crash, some_dir will be gone
+ * unless the fsync of some_file forces a full commit
+ *
+ * 2) we must log any new names for any file or dir that is in the fsync
+ * log. ---> check inode while renaming/linking.
+ *
+ * 2a) we must log any new names for any file or dir during rename
+ * when the directory they are being removed from was logged.
+ * ---> check inode and old parent dir during rename
+ *
+ * 2a is actually the more important variant. With the extra logging
+ * a crash might unlink the old name without recreating the new one
+ *
+ * 3) after a crash, we must go through any directories with a link count
+ * of zero and redo the rm -rf
+ *
+ * mkdir f1/foo
+ * normal commit
+ * rm -rf f1/foo
+ * fsync(f1)
+ *
+ * The directory f1 was fully removed from the FS, but fsync was never
+ * called on f1, only its parent dir. After a crash the rm -rf must
+ * be replayed. This must be able to recurse down the entire
+ * directory tree. The inode link count fixup code takes care of the
+ * ugly details.
+ */
+
/*
* stages for the tree walking. The first
* stage (0) is to only pin down the blocks we find
#define LOG_WALK_REPLAY_INODES 1
#define LOG_WALK_REPLAY_ALL 2
-static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
int inode_only);
static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid);
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid, int del_all);
/*
* tree logging is a special write ahead log used to make sure that
return ret;
}
+/*
+ * This either makes the current running log transaction wait
+ * until you call btrfs_end_log_trans() or it makes any future
+ * log transactions wait until you call btrfs_end_log_trans()
+ */
+int btrfs_pin_log_trans(struct btrfs_root *root)
+{
+ int ret = -ENOENT;
+
+ mutex_lock(&root->log_mutex);
+ atomic_inc(&root->log_writers);
+ mutex_unlock(&root->log_mutex);
+ return ret;
+}
+
/*
* indicate we're done making changes to the log tree
* and wake up anyone waiting to do a sync
*/
-static int end_log_trans(struct btrfs_root *root)
+int btrfs_end_log_trans(struct btrfs_root *root)
{
if (atomic_dec_and_test(&root->log_writers)) {
smp_mb();
mutex_lock(&log->fs_info->pinned_mutex);
btrfs_update_pinned_extents(log->fs_info->extent_root,
eb->start, eb->len, 1);
- mutex_unlock(&log->fs_info->pinned_mutex);
}
if (btrfs_buffer_uptodate(eb, gen)) {
ret = link_to_fixup_dir(trans, root, path, location.objectid);
BUG_ON(ret);
+
ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
BUG_ON(ret);
kfree(name);
victim_name_len)) {
btrfs_inc_nlink(inode);
btrfs_release_path(root, path);
+
ret = btrfs_unlink_inode(trans, root, dir,
inode, victim_name,
victim_name_len);
key.offset--;
btrfs_release_path(root, path);
}
- btrfs_free_path(path);
+ btrfs_release_path(root, path);
if (nlink != inode->i_nlink) {
inode->i_nlink = nlink;
btrfs_update_inode(trans, root, inode);
}
BTRFS_I(inode)->index_cnt = (u64)-1;
+ if (inode->i_nlink == 0 && S_ISDIR(inode->i_mode)) {
+ ret = replay_dir_deletes(trans, root, NULL, path,
+ inode->i_ino, 1);
+ BUG_ON(ret);
+ }
+ btrfs_free_path(path);
+
return 0;
}
iput(inode);
- if (key.offset == 0)
- break;
- key.offset--;
+ /*
+ * fixup on a directory may create new entries,
+ * make sure we always look for the highset possible
+ * offset
+ */
+ key.offset = (u64)-1;
}
btrfs_release_path(root, path);
return 0;
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
log_di = NULL;
- if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
+ if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
log_di = btrfs_lookup_dir_item(trans, log, log_path,
dir_key->objectid,
name, name_len, 0);
- } else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
+ } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
log_di = btrfs_lookup_dir_index_item(trans, log,
log_path,
dir_key->objectid,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
- u64 dirid)
+ u64 dirid, int del_all)
{
u64 range_start;
u64 range_end;
range_start = 0;
range_end = 0;
while (1) {
- ret = find_dir_range(log, path, dirid, key_type,
- &range_start, &range_end);
- if (ret != 0)
- break;
+ if (del_all)
+ range_end = (u64)-1;
+ else {
+ ret = find_dir_range(log, path, dirid, key_type,
+ &range_start, &range_end);
+ if (ret != 0)
+ break;
+ }
dir_key.offset = range_start;
while (1) {
break;
ret = check_item_in_log(trans, root, log, path,
- log_path, dir, &found_key);
+ log_path, dir,
+ &found_key);
BUG_ON(ret);
if (found_key.offset == (u64)-1)
break;
mode = btrfs_inode_mode(eb, inode_item);
if (S_ISDIR(mode)) {
ret = replay_dir_deletes(wc->trans,
- root, log, path, key.objectid);
+ root, log, path, key.objectid, 0);
BUG_ON(ret);
}
ret = overwrite_item(wc->trans, root, path,
root, inode, inode->i_size,
BTRFS_EXTENT_DATA_KEY);
BUG_ON(ret);
+
+ /* if the nlink count is zero here, the iput
+ * will free the inode. We bump it to make
+ * sure it doesn't get freed until the link
+ * count fixup is done
+ */
+ if (inode->i_nlink == 0) {
+ btrfs_inc_nlink(inode);
+ btrfs_update_inode(wc->trans,
+ root, inode);
+ }
iput(inode);
}
ret = link_to_fixup_dir(wc->trans, root,
return ret;
}
-static int wait_log_commit(struct btrfs_root *root, unsigned long transid)
+static int wait_log_commit(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, unsigned long transid)
{
DEFINE_WAIT(wait);
int index = transid % 2;
prepare_to_wait(&root->log_commit_wait[index],
&wait, TASK_UNINTERRUPTIBLE);
mutex_unlock(&root->log_mutex);
- if (root->log_transid < transid + 2 &&
+
+ if (root->fs_info->last_trans_log_full_commit !=
+ trans->transid && root->log_transid < transid + 2 &&
atomic_read(&root->log_commit[index]))
schedule();
+
finish_wait(&root->log_commit_wait[index], &wait);
mutex_lock(&root->log_mutex);
} while (root->log_transid < transid + 2 &&
return 0;
}
-static int wait_for_writer(struct btrfs_root *root)
+static int wait_for_writer(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
{
DEFINE_WAIT(wait);
while (atomic_read(&root->log_writers)) {
prepare_to_wait(&root->log_writer_wait,
&wait, TASK_UNINTERRUPTIBLE);
mutex_unlock(&root->log_mutex);
- if (atomic_read(&root->log_writers))
+ if (root->fs_info->last_trans_log_full_commit !=
+ trans->transid && atomic_read(&root->log_writers))
schedule();
mutex_lock(&root->log_mutex);
finish_wait(&root->log_writer_wait, &wait);
/*
* btrfs_sync_log does sends a given tree log down to the disk and
* updates the super blocks to record it. When this call is done,
- * you know that any inodes previously logged are safely on disk
+ * you know that any inodes previously logged are safely on disk only
+ * if it returns 0.
+ *
+ * Any other return value means you need to call btrfs_commit_transaction.
+ * Some of the edge cases for fsyncing directories that have had unlinks
+ * or renames done in the past mean that sometimes the only safe
+ * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
+ * that has happened.
*/
int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
mutex_lock(&root->log_mutex);
index1 = root->log_transid % 2;
if (atomic_read(&root->log_commit[index1])) {
- wait_log_commit(root, root->log_transid);
+ wait_log_commit(trans, root, root->log_transid);
mutex_unlock(&root->log_mutex);
return 0;
}
/* wait for previous tree log sync to complete */
if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
- wait_log_commit(root, root->log_transid - 1);
+ wait_log_commit(trans, root, root->log_transid - 1);
while (1) {
unsigned long batch = root->log_batch;
mutex_unlock(&root->log_mutex);
schedule_timeout_uninterruptible(1);
mutex_lock(&root->log_mutex);
- wait_for_writer(root);
+
+ wait_for_writer(trans, root);
if (batch == root->log_batch)
break;
}
+ /* bail out if we need to do a full commit */
+ if (root->fs_info->last_trans_log_full_commit == trans->transid) {
+ ret = -EAGAIN;
+ mutex_unlock(&root->log_mutex);
+ goto out;
+ }
+
ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
BUG_ON(ret);
index2 = log_root_tree->log_transid % 2;
if (atomic_read(&log_root_tree->log_commit[index2])) {
- wait_log_commit(log_root_tree, log_root_tree->log_transid);
+ wait_log_commit(trans, log_root_tree,
+ log_root_tree->log_transid);
mutex_unlock(&log_root_tree->log_mutex);
goto out;
}
atomic_set(&log_root_tree->log_commit[index2], 1);
- if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2]))
- wait_log_commit(log_root_tree, log_root_tree->log_transid - 1);
+ if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
+ wait_log_commit(trans, log_root_tree,
+ log_root_tree->log_transid - 1);
+ }
+
+ wait_for_writer(trans, log_root_tree);
- wait_for_writer(log_root_tree);
+ /*
+ * now that we've moved on to the tree of log tree roots,
+ * check the full commit flag again
+ */
+ if (root->fs_info->last_trans_log_full_commit == trans->transid) {
+ mutex_unlock(&log_root_tree->log_mutex);
+ ret = -EAGAIN;
+ goto out_wake_log_root;
+ }
ret = btrfs_write_and_wait_marked_extents(log_root_tree,
&log_root_tree->dirty_log_pages);
* in and cause problems either.
*/
write_ctree_super(trans, root->fs_info->tree_root, 2);
+ ret = 0;
+out_wake_log_root:
atomic_set(&log_root_tree->log_commit[index2], 0);
smp_mb();
if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
return 0;
}
-/* * free all the extents used by the tree log. This should be called
+/*
+ * free all the extents used by the tree log. This should be called
* at commit time of the full transaction
*/
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
btrfs_free_path(path);
mutex_unlock(&BTRFS_I(dir)->log_mutex);
- end_log_trans(root);
+ btrfs_end_log_trans(root);
return 0;
}
ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
dirid, &index);
mutex_unlock(&BTRFS_I(inode)->log_mutex);
- end_log_trans(root);
+ btrfs_end_log_trans(root);
return ret;
}
*
* This handles both files and directories.
*/
-static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
int inode_only)
{
min_key.offset = 0;
max_key.objectid = inode->i_ino;
+
+ /* today the code can only do partial logging of directories */
+ if (!S_ISDIR(inode->i_mode))
+ inode_only = LOG_INODE_ALL;
+
if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
max_key.type = BTRFS_XATTR_ITEM_KEY;
else
max_key.type = (u8)-1;
max_key.offset = (u64)-1;
- /*
- * if this inode has already been logged and we're in inode_only
- * mode, we don't want to delete the things that have already
- * been written to the log.
- *
- * But, if the inode has been through an inode_only log,
- * the logged_trans field is not set. This allows us to catch
- * any new names for this inode in the backrefs by logging it
- * again
- */
- if (inode_only == LOG_INODE_EXISTS &&
- BTRFS_I(inode)->logged_trans == trans->transid) {
- btrfs_free_path(path);
- btrfs_free_path(dst_path);
- goto out;
- }
mutex_lock(&BTRFS_I(inode)->log_mutex);
/*
if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
btrfs_release_path(root, path);
btrfs_release_path(log, dst_path);
- BTRFS_I(inode)->log_dirty_trans = 0;
ret = log_directory_changes(trans, root, inode, path, dst_path);
BUG_ON(ret);
}
btrfs_free_path(path);
btrfs_free_path(dst_path);
-out:
return 0;
}
-int btrfs_log_inode(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, struct inode *inode,
- int inode_only)
+/*
+ * follow the dentry parent pointers up the chain and see if any
+ * of the directories in it require a full commit before they can
+ * be logged. Returns zero if nothing special needs to be done or 1 if
+ * a full commit is required.
+ */
+static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
+ struct inode *inode,
+ struct dentry *parent,
+ struct super_block *sb,
+ u64 last_committed)
{
- int ret;
+ int ret = 0;
+ struct btrfs_root *root;
- start_log_trans(trans, root);
- ret = __btrfs_log_inode(trans, root, inode, inode_only);
- end_log_trans(root);
+ /*
+ * for regular files, if its inode is already on disk, we don't
+ * have to worry about the parents at all. This is because
+ * we can use the last_unlink_trans field to record renames
+ * and other fun in this file.
+ */
+ if (S_ISREG(inode->i_mode) &&
+ BTRFS_I(inode)->generation <= last_committed &&
+ BTRFS_I(inode)->last_unlink_trans <= last_committed)
+ goto out;
+
+ if (!S_ISDIR(inode->i_mode)) {
+ if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
+ goto out;
+ inode = parent->d_inode;
+ }
+
+ while (1) {
+ BTRFS_I(inode)->logged_trans = trans->transid;
+ smp_mb();
+
+ if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
+ root = BTRFS_I(inode)->root;
+
+ /*
+ * make sure any commits to the log are forced
+ * to be full commits
+ */
+ root->fs_info->last_trans_log_full_commit =
+ trans->transid;
+ ret = 1;
+ break;
+ }
+
+ if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
+ break;
+
+ if (parent == sb->s_root)
+ break;
+
+ parent = parent->d_parent;
+ inode = parent->d_inode;
+
+ }
+out:
return ret;
}
* only logging is done of any parent directories that are older than
* the last committed transaction
*/
-int btrfs_log_dentry(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, struct dentry *dentry)
+int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct inode *inode,
+ struct dentry *parent, int exists_only)
{
- int inode_only = LOG_INODE_ALL;
+ int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
struct super_block *sb;
- int ret;
+ int ret = 0;
+ u64 last_committed = root->fs_info->last_trans_committed;
+
+ sb = inode->i_sb;
+
+ if (root->fs_info->last_trans_log_full_commit >
+ root->fs_info->last_trans_committed) {
+ ret = 1;
+ goto end_no_trans;
+ }
+
+ ret = check_parent_dirs_for_sync(trans, inode, parent,
+ sb, last_committed);
+ if (ret)
+ goto end_no_trans;
start_log_trans(trans, root);
- sb = dentry->d_inode->i_sb;
- while (1) {
- ret = __btrfs_log_inode(trans, root, dentry->d_inode,
- inode_only);
- BUG_ON(ret);
- inode_only = LOG_INODE_EXISTS;
- dentry = dentry->d_parent;
- if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
+ ret = btrfs_log_inode(trans, root, inode, inode_only);
+ BUG_ON(ret);
+
+ /*
+ * for regular files, if its inode is already on disk, we don't
+ * have to worry about the parents at all. This is because
+ * we can use the last_unlink_trans field to record renames
+ * and other fun in this file.
+ */
+ if (S_ISREG(inode->i_mode) &&
+ BTRFS_I(inode)->generation <= last_committed &&
+ BTRFS_I(inode)->last_unlink_trans <= last_committed)
+ goto no_parent;
+
+ inode_only = LOG_INODE_EXISTS;
+ while (1) {
+ if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
break;
- if (BTRFS_I(dentry->d_inode)->generation <=
- root->fs_info->last_trans_committed)
+ inode = parent->d_inode;
+ if (BTRFS_I(inode)->generation >
+ root->fs_info->last_trans_committed) {
+ ret = btrfs_log_inode(trans, root, inode, inode_only);
+ BUG_ON(ret);
+ }
+ if (parent == sb->s_root)
break;
+
+ parent = parent->d_parent;
}
- end_log_trans(root);
- return 0;
+no_parent:
+ ret = 0;
+ btrfs_end_log_trans(root);
+end_no_trans:
+ return ret;
}
/*
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct dentry *dentry)
{
- u64 gen;
- gen = root->fs_info->last_trans_new_blockgroup;
- if (gen > root->fs_info->last_trans_committed)
- return 1;
- else
- return btrfs_log_dentry(trans, root, dentry);
+ return btrfs_log_inode_parent(trans, root, dentry->d_inode,
+ dentry->d_parent, 0);
}
/*
kfree(log_root_tree);
return 0;
}
+
+/*
+ * there are some corner cases where we want to force a full
+ * commit instead of allowing a directory to be logged.
+ *
+ * They revolve around files there were unlinked from the directory, and
+ * this function updates the parent directory so that a full commit is
+ * properly done if it is fsync'd later after the unlinks are done.
+ */
+void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
+ struct inode *dir, struct inode *inode,
+ int for_rename)
+{
+ /*
+ * when we're logging a file, if it hasn't been renamed
+ * or unlinked, and its inode is fully committed on disk,
+ * we don't have to worry about walking up the directory chain
+ * to log its parents.
+ *
+ * So, we use the last_unlink_trans field to put this transid
+ * into the file. When the file is logged we check it and
+ * don't log the parents if the file is fully on disk.
+ */
+ if (S_ISREG(inode->i_mode))
+ BTRFS_I(inode)->last_unlink_trans = trans->transid;
+
+ /*
+ * if this directory was already logged any new
+ * names for this file/dir will get recorded
+ */
+ smp_mb();
+ if (BTRFS_I(dir)->logged_trans == trans->transid)
+ return;
+
+ /*
+ * if the inode we're about to unlink was logged,
+ * the log will be properly updated for any new names
+ */
+ if (BTRFS_I(inode)->logged_trans == trans->transid)
+ return;
+
+ /*
+ * when renaming files across directories, if the directory
+ * there we're unlinking from gets fsync'd later on, there's
+ * no way to find the destination directory later and fsync it
+ * properly. So, we have to be conservative and force commits
+ * so the new name gets discovered.
+ */
+ if (for_rename)
+ goto record;
+
+ /* we can safely do the unlink without any special recording */
+ return;
+
+record:
+ BTRFS_I(dir)->last_unlink_trans = trans->transid;
+}
+
+/*
+ * Call this after adding a new name for a file and it will properly
+ * update the log to reflect the new name.
+ *
+ * It will return zero if all goes well, and it will return 1 if a
+ * full transaction commit is required.
+ */
+int btrfs_log_new_name(struct btrfs_trans_handle *trans,
+ struct inode *inode, struct inode *old_dir,
+ struct dentry *parent)
+{
+ struct btrfs_root * root = BTRFS_I(inode)->root;
+
+ /*
+ * this will force the logging code to walk the dentry chain
+ * up for the file
+ */
+ if (S_ISREG(inode->i_mode))
+ BTRFS_I(inode)->last_unlink_trans = trans->transid;
+
+ /*
+ * if this inode hasn't been logged and directory we're renaming it
+ * from hasn't been logged, we don't need to log it
+ */
+ if (BTRFS_I(inode)->logged_trans <=
+ root->fs_info->last_trans_committed &&
+ (!old_dir || BTRFS_I(old_dir)->logged_trans <=
+ root->fs_info->last_trans_committed))
+ return 0;
+
+ return btrfs_log_inode_parent(trans, root, inode, parent, 1);
+}
+
git.openpandora.org / pandora-kernel.git / blobdiff