@@ -44,6 +44,7 @@
#include "scrub/reap.h"
#include "scrub/findparent.h"
#include "scrub/orphanage.h"
+#include "scrub/listxattr.h"
/*
* Directory Repair
@@ -58,6 +59,15 @@
* being repaired and the temporary directory, and will later become important
* for parent pointer scanning.
*
+ * If parent pointers are enabled on this filesystem, we instead reconstruct
+ * the directory by visiting each parent pointer of each file in the filesystem
+ * and translating the relevant parent pointer records into dirents. In this
+ * case, it is advantageous to stash all directory entries created from parent
+ * pointers for a single child file before replaying them into the temporary
+ * directory. To save memory, the live filesystem scan reuses the findparent
+ * fields. Directory repair chooses either parent pointer scanning or
+ * directory entry salvaging, but not both.
+ *
* Directory entries added to the temporary directory do not elevate the link
* counts of the inodes found. When salvaging completes, the remaining stashed
* entries are replayed to the temporary directory. An atomic extent swap is
@@ -113,7 +123,15 @@ struct xrep_dir {
/*
* Information used to scan the filesystem to find the inumber of the
- * dotdot entry for this directory.
+ * dotdot entry for this directory. For directory salvaging when
+ * parent pointers are not enabled, we use the findparent_* functions
+ * on this object and access only the parent_ino field directly.
+ *
+ * When parent pointers are enabled, however, the pptr scanner uses the
+ * iscan, hooks, lock, and parent_ino fields of this object directly.
+ * @pscan.lock coordinates access to dir_entries, dir_names,
+ * parent_ino, subdirs, dirents, and args. This reduces the memory
+ * requirements of this structure.
*/
struct xrep_parent_scan_info pscan;
@@ -999,6 +1017,259 @@ xrep_dir_salvage_entries(
}
+/*
+ * Examine an xattr of a file. If this xattr is a parent pointer that leads us
+ * back to the directory that we're rebuilding, create an incore dirent from
+ * the parent pointer and stash it.
+ */
+STATIC int
+xrep_dir_scan_parent_pointer(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip,
+ unsigned int attr_flags,
+ const unsigned char *name,
+ unsigned int namelen,
+ const void *value,
+ unsigned int valuelen,
+ void *priv)
+{
+ struct xfs_name xname;
+ struct xrep_dir *rd = priv;
+ const struct xfs_parent_name_rec *rec = (const void *)name;
+ int error;
+
+ /* Ignore incomplete xattrs */
+ if (attr_flags & XFS_ATTR_INCOMPLETE)
+ return 0;
+
+ /* Ignore anything that isn't a parent pointer. */
+ if (!(attr_flags & XFS_ATTR_PARENT))
+ return 0;
+
+ /* Does the ondisk parent pointer structure make sense? */
+ if (!xfs_parent_namecheck(sc->mp, rec, namelen, attr_flags) ||
+ !xfs_parent_valuecheck(sc->mp, value, valuelen))
+ return -EFSCORRUPTED;
+
+ xfs_parent_irec_from_disk(&rd->pptr, rec, value, valuelen);
+
+ /* Ignore parent pointers that point back to a different dir. */
+ if (rd->pptr.p_ino != sc->ip->i_ino ||
+ rd->pptr.p_gen != VFS_I(sc->ip)->i_generation)
+ return 0;
+
+ /*
+ * Transform this parent pointer into a dirent and queue it for later
+ * addition to the temporary directory.
+ */
+ xname.name = rd->pptr.p_name;
+ xname.len = rd->pptr.p_namelen;
+ xname.type = xfs_mode_to_ftype(VFS_I(ip)->i_mode);
+
+ mutex_lock(&rd->pscan.lock);
+ error = xrep_dir_stash_createname(rd, &xname, ip->i_ino);
+ mutex_unlock(&rd->pscan.lock);
+ return error;
+}
+
+/*
+ * If this child dirent points to the directory being repaired, remember that
+ * fact so that we can reset the dotdot entry if necessary.
+ */
+STATIC int
+xrep_dir_scan_dirent(
+ struct xfs_scrub *sc,
+ struct xfs_inode *dp,
+ xfs_dir2_dataptr_t dapos,
+ const struct xfs_name *name,
+ xfs_ino_t ino,
+ void *priv)
+{
+ struct xrep_dir *rd = priv;
+
+ /* Dirent doesn't point to this directory. */
+ if (ino != rd->sc->ip->i_ino)
+ return 0;
+
+ /* Ignore garbage inum. */
+ if (!xfs_verify_dir_ino(rd->sc->mp, ino))
+ return 0;
+
+ /* No weird looking names. */
+ if (name->len >= MAXNAMELEN || name->len <= 0)
+ return 0;
+
+ /* Don't pick up dot or dotdot entries; we only want child dirents. */
+ if (xfs_dir2_samename(name, &xfs_name_dotdot) ||
+ xfs_dir2_samename(name, &xfs_name_dot))
+ return 0;
+
+ trace_xrep_dir_stash_createname(sc->tempip, &xfs_name_dotdot,
+ dp->i_ino);
+
+ xrep_findparent_scan_found(&rd->pscan, dp->i_ino);
+ return 0;
+}
+
+/*
+ * Decide if we want to look for child dirents or parent pointers in this file.
+ * Skip the dir being repaired and any files being used to stage repairs.
+ */
+static inline bool
+xrep_dir_want_scan(
+ struct xrep_dir *rd,
+ const struct xfs_inode *ip)
+{
+ return ip != rd->sc->ip && !xrep_is_tempfile(ip);
+}
+
+/*
+ * Take ILOCK on a file that we want to scan.
+ *
+ * Select ILOCK_EXCL if the file is a directory with an unloaded data bmbt or
+ * has an unloaded attr bmbt. Otherwise, take ILOCK_SHARED.
+ */
+static inline unsigned int
+xrep_dir_scan_ilock(
+ struct xrep_dir *rd,
+ struct xfs_inode *ip)
+{
+ uint lock_mode = XFS_ILOCK_SHARED;
+
+ /* Need to take the shared ILOCK to advance the iscan cursor. */
+ if (!xrep_dir_want_scan(rd, ip))
+ goto lock;
+
+ if (S_ISDIR(VFS_I(ip)->i_mode) && xfs_need_iread_extents(&ip->i_df)) {
+ lock_mode = XFS_ILOCK_EXCL;
+ goto lock;
+ }
+
+ if (xfs_inode_has_attr_fork(ip) && xfs_need_iread_extents(&ip->i_af))
+ lock_mode = XFS_ILOCK_EXCL;
+
+lock:
+ xfs_ilock(ip, lock_mode);
+ return lock_mode;
+}
+
+/*
+ * Scan this file for relevant child dirents or parent pointers that point to
+ * the directory we're rebuilding.
+ */
+STATIC int
+xrep_dir_scan_file(
+ struct xrep_dir *rd,
+ struct xfs_inode *ip)
+{
+ unsigned int lock_mode;
+ int error = 0;
+
+ lock_mode = xrep_dir_scan_ilock(rd, ip);
+
+ if (!xrep_dir_want_scan(rd, ip))
+ goto scan_done;
+
+ error = xchk_xattr_walk(rd->sc, ip, xrep_dir_scan_parent_pointer, rd);
+ if (error)
+ goto scan_done;
+
+ if (S_ISDIR(VFS_I(ip)->i_mode)) {
+ error = xchk_dir_walk(rd->sc, ip, xrep_dir_scan_dirent, rd);
+ if (error)
+ goto scan_done;
+ }
+
+scan_done:
+ xchk_iscan_mark_visited(&rd->pscan.iscan, ip);
+ xfs_iunlock(ip, lock_mode);
+ return error;
+}
+
+/*
+ * Scan all files in the filesystem for parent pointers that we can turn into
+ * replacement dirents, and a dirent that we can use to set the dotdot pointer.
+ */
+STATIC int
+xrep_dir_scan_dirtree(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ struct xfs_inode *ip;
+ int error;
+
+ /* Roots of directory trees are their own parents. */
+ if (sc->ip == sc->mp->m_rootip)
+ xrep_findparent_scan_found(&rd->pscan, sc->ip->i_ino);
+
+ /*
+ * Filesystem scans are time consuming. Drop the directory ILOCK and
+ * all other resources for the duration of the scan and hope for the
+ * best. The live update hooks will keep our scan information up to
+ * date even though we've dropped the locks.
+ */
+ xchk_trans_cancel(sc);
+ if (sc->ilock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL))
+ xchk_iunlock(sc, sc->ilock_flags & (XFS_ILOCK_SHARED |
+ XFS_ILOCK_EXCL));
+ error = xchk_trans_alloc_empty(sc);
+ if (error)
+ return error;
+
+ while ((error = xchk_iscan_iter(&rd->pscan.iscan, &ip)) == 1) {
+ bool flush;
+
+ error = xrep_dir_scan_file(rd, ip);
+ xchk_irele(sc, ip);
+ if (error)
+ break;
+
+ /* Flush stashed dirent updates to constrain memory usage. */
+ mutex_lock(&rd->pscan.lock);
+ flush = xrep_dir_want_flush_stashed(rd);
+ mutex_unlock(&rd->pscan.lock);
+ if (flush) {
+ xchk_trans_cancel(sc);
+
+ error = xrep_tempfile_iolock_polled(sc);
+ if (error)
+ break;
+
+ mutex_lock(&rd->pscan.lock);
+ error = xrep_dir_replay_updates(rd);
+ mutex_unlock(&rd->pscan.lock);
+ xrep_tempfile_iounlock(sc);
+ if (error)
+ break;
+
+ error = xchk_trans_alloc_empty(sc);
+ if (error)
+ break;
+ }
+
+ if (xchk_should_terminate(sc, &error))
+ break;
+ }
+ xchk_iscan_iter_finish(&rd->pscan.iscan);
+ if (error) {
+ /*
+ * If we couldn't grab an inode that was busy with a state
+ * change, change the error code so that we exit to userspace
+ * as quickly as possible.
+ */
+ if (error == -EBUSY)
+ return -ECANCELED;
+ return error;
+ }
+
+ /*
+ * Cancel the empty transaction so that we can (later) use the atomic
+ * extent swap helpers to lock files and commit the new directory.
+ */
+ xchk_trans_cancel(rd->sc);
+ return 0;
+}
+
/*
* Free all the directory blocks and reset the data fork. The caller must
* join the inode to the transaction. This function returns with the inode
@@ -1198,6 +1469,44 @@ xrep_dir_set_nlink(
return 0;
}
+/*
+ * Finish replaying stashed dirent updates, allocate a transaction for swapping
+ * extents, and take the ILOCKs of both directories before we commit the new
+ * directory structure.
+ */
+STATIC int
+xrep_dir_finalize_tempdir(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ int error;
+
+ if (!xfs_has_parent(sc->mp))
+ return xrep_tempswap_trans_alloc(sc, XFS_DATA_FORK, &rd->tx);
+
+ do {
+ error = xrep_dir_replay_updates(rd);
+ if (error)
+ return error;
+
+ error = xrep_tempswap_trans_alloc(sc, XFS_DATA_FORK, &rd->tx);
+ if (error)
+ return error;
+
+ /*
+ * We rely on the ILOCK to quiesce all directory updates
+ * because the VFS does not take the IOLOCK when moving a
+ * directory child during a rename.
+ */
+ if (xfarray_length(rd->dir_entries) == 0)
+ break;
+
+ xchk_trans_cancel(sc);
+ xrep_tempfile_iunlock_both(sc);
+ } while (!xchk_should_terminate(sc, &error));
+ return error;
+}
+
/* Swap the temporary directory's data fork with the one being repaired. */
STATIC int
xrep_dir_swap(
@@ -1297,7 +1606,12 @@ xrep_dir_rebuild_tree(
if (error)
return error;
- error = xrep_tempswap_trans_alloc(sc, XFS_DATA_FORK, &rd->tx);
+ /*
+ * Allocate transaction, lock inodes, and make sure that we've replayed
+ * all the stashed dirent updates to the tempdir. After this point,
+ * we're ready to swapext.
+ */
+ error = xrep_dir_finalize_tempdir(rd);
if (error)
return error;
@@ -1464,7 +1778,10 @@ xrep_directory(
if (error)
return error;
- error = xrep_dir_salvage_entries(rd);
+ if (xfs_has_parent(sc->mp))
+ error = xrep_dir_scan_dirtree(rd);
+ else
+ error = xrep_dir_salvage_entries(rd);
if (error)
goto out_teardown;