diff options
| -rw-r--r-- | fs/xfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/xfs/scrub/dir_repair.c | 60 | ||||
| -rw-r--r-- | fs/xfs/scrub/iscan.c | 7 | ||||
| -rw-r--r-- | fs/xfs/scrub/iscan.h | 3 | ||||
| -rw-r--r-- | fs/xfs/scrub/parent.c | 3 | ||||
| -rw-r--r-- | fs/xfs/scrub/parent.h | 16 | ||||
| -rw-r--r-- | fs/xfs/scrub/parent_repair.c | 413 | ||||
| -rw-r--r-- | fs/xfs/scrub/repair.h | 2 | ||||
| -rw-r--r-- | fs/xfs/scrub/scrub.c | 2 | ||||
| -rw-r--r-- | fs/xfs/scrub/trace.h | 2 |
10 files changed, 476 insertions, 33 deletions
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index d390ab15090a..5671f221400c 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -194,6 +194,7 @@ xfs-y += $(addprefix scrub/, \ inode_repair.o \ newbt.o \ nlinks_repair.o \ + parent_repair.o \ reap.o \ refcount_repair.o \ repair.o \ diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c index 85b628565ac9..e7d52c77456b 100644 --- a/fs/xfs/scrub/dir_repair.c +++ b/fs/xfs/scrub/dir_repair.c @@ -38,6 +38,7 @@ #include "scrub/xfblob.h" #include "scrub/readdir.h" #include "scrub/reap.h" +#include "scrub/parent.h" /* * Directory Repair @@ -1017,50 +1018,36 @@ xrep_dir_rebuild_tree( } /* - * If we're the root of a directory tree, we are our own parent. If we're an - * unlinked directory, the parent /won't/ have a link to us. Set the parent - * directory to the root for both cases. Returns NULLFSINO if we don't know - * what to do. + * Look up the dotdot entry and confirm that it's really the parent. + * Returns NULLFSINO if we don't know what to do. */ static inline xfs_ino_t -xrep_dir_self_parent( +xrep_dir_lookup_parent( struct xrep_dir *rd) { struct xfs_scrub *sc = rd->sc; + xfs_ino_t parent_ino; + int error; - if (sc->ip->i_ino == sc->mp->m_sb.sb_rootino) - return sc->mp->m_sb.sb_rootino; + parent_ino = xrep_dotdot_lookup(sc); + if (parent_ino == NULLFSINO) + return parent_ino; - if (VFS_I(sc->ip)->i_nlink == 0) - return sc->mp->m_sb.sb_rootino; + error = xrep_parent_confirm(sc, &parent_ino); + if (error) + return NULLFSINO; - return NULLFSINO; + return parent_ino; } -/* - * Look up the dotdot entry. Returns NULLFSINO if we don't know what to do. - * The next patch will check this more carefully. - */ -static inline xfs_ino_t -xrep_dir_lookup_parent( - struct xrep_dir *rd) -{ - return xrep_dotdot_lookup(rd->sc); -} - -/* - * Try to find the parent of the directory being repaired. - * - * NOTE: This function will someday be augmented by the directory parent repair - * code, which will know how to check the parent and scan the filesystem if - * we cannot find anything. Inode scans will have to be done before we start - * salvaging directory entries, so we do this now. - */ +/* Try to find the parent of the directory being repaired. */ STATIC int xrep_dir_find_parent( struct xrep_dir *rd) { - rd->parent_ino = xrep_dir_self_parent(rd); + int error; + + rd->parent_ino = xrep_parent_self_reference(rd->sc); if (rd->parent_ino != NULLFSINO) return 0; @@ -1068,6 +1055,19 @@ xrep_dir_find_parent( if (rd->parent_ino != NULLFSINO) return 0; + /* + * A full filesystem scan is the last resort. On a busy filesystem, + * the scan can fail with -EBUSY if we cannot grab IOLOCKs. That means + * that we don't know what who the parent is, so we should return to + * userspace. + */ + error = xrep_parent_scan(rd->sc, &rd->parent_ino); + if (error) + return error; + + if (rd->parent_ino != NULLFSINO) + return 0; + /* NOTE: A future patch will deal with moving orphans. */ return -EFSCORRUPTED; } diff --git a/fs/xfs/scrub/iscan.c b/fs/xfs/scrub/iscan.c index 29ab56927d8a..cc3bc098818b 100644 --- a/fs/xfs/scrub/iscan.c +++ b/fs/xfs/scrub/iscan.c @@ -342,8 +342,13 @@ xchk_iscan_iget( * It's possible that this inode has lost all of its links but * hasn't yet been inactivated. If we don't have a transaction * or it's not writable, flush the inodegc workers and wait. + * Otherwise, we have a dirty transaction in progress and the + * best we can do is to queue the inodegc workers. */ - xfs_inodegc_flush(mp); + if (!iscan->iget_nowait) + xfs_inodegc_flush(mp); + else + xfs_inodegc_push(mp); return xchk_iscan_iget_retry(mp, iscan, true); } diff --git a/fs/xfs/scrub/iscan.h b/fs/xfs/scrub/iscan.h index 947176620bc3..f10b71d9cec4 100644 --- a/fs/xfs/scrub/iscan.h +++ b/fs/xfs/scrub/iscan.h @@ -32,6 +32,9 @@ struct xchk_iscan { /* Wait this many ms to retry an iget. */ unsigned int iget_retry_delay; + + /* True if we cannot allow iget to wait indefinitely. */ + bool iget_nowait:1; }; /* Set if the scan has been aborted due to some event in the fs. */ diff --git a/fs/xfs/scrub/parent.c b/fs/xfs/scrub/parent.c index 9ca8cfe3d3d3..120e3be383fe 100644 --- a/fs/xfs/scrub/parent.c +++ b/fs/xfs/scrub/parent.c @@ -17,6 +17,7 @@ #include "scrub/scrub.h" #include "scrub/common.h" #include "scrub/readdir.h" +#include "scrub/parent.h" /* Set us up to scrub parents. */ int @@ -68,7 +69,7 @@ xchk_parent_actor( * Try to iolock the parent dir @dp in shared mode and the child dir @sc->ip * exclusively. */ -STATIC int +int xchk_parent_lock_two_dirs( struct xfs_scrub *sc, struct xfs_inode *dp) diff --git a/fs/xfs/scrub/parent.h b/fs/xfs/scrub/parent.h new file mode 100644 index 000000000000..e1979f5bb001 --- /dev/null +++ b/fs/xfs/scrub/parent.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2022 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#ifndef __XFS_SCRUB_PARENT_H__ +#define __XFS_SCRUB_PARENT_H__ + +int xchk_parent_lock_two_dirs(struct xfs_scrub *sc, struct xfs_inode *dp); + +int xrep_parent_confirm(struct xfs_scrub *sc, xfs_ino_t *parent_ino); +int xrep_parent_scan(struct xfs_scrub *sc, xfs_ino_t *parent_ino); + +xfs_ino_t xrep_parent_self_reference(struct xfs_scrub *sc); + +#endif /* __XFS_SCRUB_PARENT_H__ */ diff --git a/fs/xfs/scrub/parent_repair.c b/fs/xfs/scrub/parent_repair.c new file mode 100644 index 000000000000..1d01d00a1501 --- /dev/null +++ b/fs/xfs/scrub/parent_repair.c @@ -0,0 +1,413 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2022 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_bit.h" +#include "xfs_log_format.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_inode.h" +#include "xfs_icache.h" +#include "xfs_da_format.h" +#include "xfs_da_btree.h" +#include "xfs_dir2.h" +#include "xfs_bmap_btree.h" +#include "xfs_dir2_priv.h" +#include "xfs_trans_space.h" +#include "xfs_health.h" +#include "xfs_swapext.h" +#include "scrub/xfs_scrub.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/trace.h" +#include "scrub/repair.h" +#include "scrub/iscan.h" +#include "scrub/parent.h" +#include "scrub/readdir.h" +#include "scrub/tempfile.h" + +struct xrep_findparent_info { + /* The directory currently being scanned. */ + struct xfs_inode *dp; + + /* + * Scrub context. We're looking for a @dp containing a directory + * entry pointing to sc->ip->i_ino. + */ + struct xfs_scrub *sc; + + /* + * Parent that we've found for sc->ip. If we're scanning the entire + * directory tree, we need this to ensure that we only find /one/ + * parent directory. + */ + xfs_ino_t found_parent; + + /* + * This is set to true if @found_parent was not observed directly from + * the directory scan but by noticing a change in dotdot entries after + * cycling the sc->ip IOLOCK. + */ + bool parent_tentative; +}; + +/* + * If this directory entry points to the scrub target inode, then the directory + * we're scanning is the parent of the scrub target inode. + */ +STATIC int +xrep_findparent_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_findparent_info *fpi = priv; + int error = 0; + + if (xchk_should_terminate(fpi->sc, &error)) + return error; + + if (ino != fpi->sc->ip->i_ino) + return 0; + + /* Ignore garbage directory entry names. */ + if (name->len == 0 || !xfs_dir2_namecheck(name->name, name->len)) + return -EFSCORRUPTED; + + /* + * Ignore dotdot and dot entries -- we're looking for parent -> child + * links only. + */ + if (name->name[0] == '.' && (name->len == 1 || + (name->len == 2 && name->name[1] == '.'))) + return 0; + + /* Uhoh, more than one parent for a dir? */ + if (fpi->found_parent != NULLFSINO && + !(fpi->parent_tentative && fpi->found_parent == fpi->dp->i_ino)) { + trace_xrep_findparent_dirent(fpi->sc->ip, 0); + return -EFSCORRUPTED; + } + + /* We found a potential parent; remember this. */ + trace_xrep_findparent_dirent(fpi->sc->ip, fpi->dp->i_ino); + fpi->found_parent = fpi->dp->i_ino; + fpi->parent_tentative = false; + return 0; +} + +/* + * If this is a directory, walk the dirents looking for any that point to the + * scrub target inode. + */ +STATIC int +xrep_findparent_walk_directory( + struct xrep_findparent_info *fpi) +{ + struct xfs_scrub *sc = fpi->sc; + struct xfs_inode *dp = fpi->dp; + unsigned int lock_mode; + int error = 0; + + /* + * The inode being scanned cannot be its own parent, nor can any + * temporary directory we created to stage this repair. + */ + if (dp == sc->ip || dp == sc->tempip) + return 0; + + /* + * Similarly, temporary files created to stage a repair cannot be the + * parent of this inode. + */ + if (xrep_is_tempfile(dp)) + return 0; + + /* Try to lock dp; if we can, we're ready to scan! */ + if (!xfs_ilock_nowait(dp, XFS_IOLOCK_SHARED)) { + xfs_ino_t orig_parent, new_parent; + + /* + * We may have to drop the lock on sc->ip to try to lock dp. + * Therefore, look up the old dotdot entry for sc->ip so that + * we can compare it after we re-lock sc->ip. + */ + orig_parent = xrep_dotdot_lookup(sc); + + error = xchk_parent_lock_two_dirs(sc, dp); + if (error) + return error; + + /* + * It is possible that sc->ip got moved elsewhere in the + * directory tree if we dropped sc->ip to grab dp. Note that + * rename operations replace the dotdot entry without checking + * the old value. + * + * If the dotdot entry was wrong but there really was only one + * parent of sc->ip, then the dotdot entry could now be + * correct. Record this new parent as a tentative parent and + * keep scanning. If there are more parents of this directory, + * we must not touch anything. + */ + new_parent = xrep_dotdot_lookup(sc); + + if (orig_parent != new_parent || VFS_I(sc->ip)->i_nlink == 0) { + fpi->found_parent = new_parent; + fpi->parent_tentative = true; + } + } + + /* + * If this directory is known to be sick, we cannot scan it reliably + * and must abort. + */ + if (xfs_inode_has_sickness(dp, XFS_SICK_INO_CORE | + XFS_SICK_INO_BMBTD | + XFS_SICK_INO_DIR)) { + error = -EFSCORRUPTED; + goto out_unlock; + } + + /* + * Scan the directory to see if there it contains an entry pointing to + * the directory that we are repairing. + */ + lock_mode = xfs_ilock_data_map_shared(dp); + error = xchk_dir_walk(sc, dp, xrep_findparent_dirent, fpi); + xfs_iunlock(dp, lock_mode); + if (error) + goto out_unlock; + +out_unlock: + xfs_iunlock(dp, XFS_IOLOCK_SHARED); + return error; +} + +/* + * Confirm that the directory @parent_ino actually contains a directory entry + * pointing to the child @sc->ip->ino. This function returns one of several + * ways: + * + * Returns 0 with @parent_ino unchanged if the parent was confirmed. + * Returns 0 with a different @parent_ino if we had to cycle inode locks to + * walk the alleged parent and the child's '..' entry was changed in the mean + * time. + * Returns 0 with @parent_ino set to NULLFSINO if the parent was not valid. + * Returns the usual negative errno if something else happened. + */ +int +xrep_parent_confirm( + struct xfs_scrub *sc, + xfs_ino_t *parent_ino) +{ + struct xrep_findparent_info fpi = { + .sc = sc, + .found_parent = NULLFSINO, + }; + int error; + + /* + * The root directory always points to itself. Unlinked dirs can point + * anywhere, so we point them at the root dir too. + */ + if (sc->ip == sc->mp->m_rootip || VFS_I(sc->ip)->i_nlink == 0) { + *parent_ino = sc->mp->m_sb.sb_rootino; + return 0; + } + + /* Reject garbage parent inode numbers and self-referential parents. */ + if (*parent_ino == NULLFSINO) + return 0; + if (!xfs_verify_dir_ino(sc->mp, *parent_ino) || + *parent_ino == sc->ip->i_ino) { + *parent_ino = NULLFSINO; + return 0; + } + + error = xchk_iget(sc, *parent_ino, &fpi.dp); + if (error) + return error; + + if (!S_ISDIR(VFS_I(fpi.dp)->i_mode)) { + *parent_ino = NULLFSINO; + goto out_rele; + } + + error = xrep_findparent_walk_directory(&fpi); + if (error) + goto out_rele; + + *parent_ino = fpi.found_parent; +out_rele: + xchk_irele(sc, fpi.dp); + return error; +} + +/* + * Scan the entire filesystem looking for a parent inode for the inode being + * scrubbed. @sc->ip must not be the root of a directory tree. + * + * Returns 0 with @parent_ino set to the parent that we found, or the current + * value of the child's '..' entry, if it changed when we had to drop the + * child's IOLOCK. + * Returns 0 with @parent_ino set to NULLFSINO if we didn't find anything. + * Returns the usual negative errno if something else happened. + */ +int +xrep_parent_scan( + struct xfs_scrub *sc, + xfs_ino_t *parent_ino) +{ + struct xrep_findparent_info fpi = { + .sc = sc, + .found_parent = NULLFSINO, + }; + struct xchk_iscan iscan = { }; + int ret; + + /* + * The caller holds a non-empty transaction and a directory ILOCK. + * Hence we cannot block the system indefinitely in iget, so we will + * retry rapidly for up to five seconds before aborting the operation. + */ + iscan.iget_nowait = true; + xchk_iscan_start(&iscan, 5000, 1); + + while ((ret = xchk_iscan_iter(sc, &iscan, &fpi.dp)) == 1) { + if (S_ISDIR(VFS_I(fpi.dp)->i_mode)) + ret = xrep_findparent_walk_directory(&fpi); + else + ret = 0; + xchk_iscan_mark_visited(&iscan, fpi.dp); + xchk_irele(sc, fpi.dp); + if (ret) + break; + + if (xchk_should_terminate(sc, &ret)) + break; + } + xchk_iscan_finish(&iscan); + if (ret) + return ret; + + *parent_ino = fpi.found_parent; + return 0; +} + +/* + * If we're the root of a directory tree, we are our own parent. If we're an + * unlinked directory, the parent /won't/ have a link to us. Set the parent + * directory to the root for both cases. Returns NULLFSINO if we don't know + * what to do. + */ +xfs_ino_t +xrep_parent_self_reference( + struct xfs_scrub *sc) +{ + if (sc->ip->i_ino == sc->mp->m_sb.sb_rootino) + return sc->mp->m_sb.sb_rootino; + + if (VFS_I(sc->ip)->i_nlink == 0) + return sc->mp->m_sb.sb_rootino; + + return NULLFSINO; +} + +/* + * Repairing The Directory Parent Pointer + * ====================================== + * + * Currently, only directories support parent pointers (in the form of '..' + * entries), so we simply scan the filesystem and update the '..' entry. + * + * Note that because the only parent pointer is the dotdot entry, we won't + * touch an unhealthy directory, since the directory repair code is perfectly + * capable of rebuilding a directory with the proper parent inode. + */ + +/* Replace a directory's parent '..' pointer. */ +STATIC int +xrep_parent_reset_dir( + struct xfs_scrub *sc, + xfs_ino_t parent_ino) +{ + unsigned int spaceres; + int error; + + trace_xrep_parent_reset_dir(sc->ip, parent_ino); + + /* + * Reserve more space just in case we have to expand the dir. We're + * allowed to exceed quota to repair inconsistent metadata. + */ + spaceres = XFS_RENAME_SPACE_RES(sc->mp, 2); + error = xfs_trans_reserve_more_inode(sc->tp, sc->ip, spaceres, 0, + true); + if (error) + return error; + + /* Replace the dotdot entry. */ + return xfs_dir_replace(sc->tp, sc->ip, &xfs_name_dotdot, parent_ino, + spaceres); +} + +int +xrep_parent( + struct xfs_scrub *sc) +{ + xfs_ino_t parent_ino, curr_parent; + unsigned int sick, checked; + int error; + + /* + * Avoid sick directories. The parent pointer scrubber dropped the + * ILOCK and MMAPLOCK, but we still hold IOLOCK_EXCL on the directory. + * There shouldn't be anyone else clearing the directory's sick status. + */ + xfs_inode_measure_sickness(sc->ip, &sick, &checked); + if (sick & XFS_SICK_INO_DIR) + return -EFSCORRUPTED; + + parent_ino = xrep_parent_self_reference(sc); + if (parent_ino != NULLFSINO) + goto reset_parent; + + /* Scan the entire filesystem for a parent. */ + error = xrep_parent_scan(sc, &parent_ino); + if (error) + return error; + if (parent_ino == NULLFSINO) + return -EFSCORRUPTED; + +reset_parent: + /* If the '..' entry is already set to the parent inode, we're done. */ + curr_parent = xrep_dotdot_lookup(sc); + if (curr_parent != NULLFSINO && curr_parent == parent_ino) + return 0; + + /* Last chance to abort before we start committing fixes. */ + if (xchk_should_terminate(sc, &error)) + return error; + + /* Re-take the ILOCK, we're going to need it to modify the dir. */ + xchk_ilock(sc, XFS_ILOCK_EXCL); + xfs_trans_ijoin(sc->tp, sc->ip, 0); + + error = xrep_ino_dqattach(sc); + if (error) + return error; + + return xrep_parent_reset_dir(sc, parent_ino); +} diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h index bc0ce5a4b414..d1a5faafcee0 100644 --- a/fs/xfs/scrub/repair.h +++ b/fs/xfs/scrub/repair.h @@ -119,6 +119,7 @@ int xrep_nlinks(struct xfs_scrub *sc); int xrep_fscounters(struct xfs_scrub *sc); int xrep_xattr(struct xfs_scrub *sc); int xrep_directory(struct xfs_scrub *sc); +int xrep_parent(struct xfs_scrub *sc); #ifdef CONFIG_XFS_RT int xrep_rtbitmap(struct xfs_scrub *sc); @@ -229,6 +230,7 @@ xrep_setup_rtsummary( #define xrep_rtsummary xrep_notsupported #define xrep_xattr xrep_notsupported #define xrep_directory xrep_notsupported +#define xrep_parent xrep_notsupported #endif /* CONFIG_XFS_ONLINE_REPAIR */ diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c index 1695e9d2f104..39ad06e6b2d0 100644 --- a/fs/xfs/scrub/scrub.c +++ b/fs/xfs/scrub/scrub.c @@ -345,7 +345,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = { .type = ST_INODE, .setup = xchk_setup_parent, .scrub = xchk_parent, - .repair = xrep_notsupported, + .repair = xrep_parent, }, [XFS_SCRUB_TYPE_RTBITMAP] = { /* realtime bitmap */ .type = ST_FS, diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index b19a1ecadad3..3ce859a23119 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -2446,6 +2446,7 @@ DEFINE_EVENT(xrep_dir_class, name, \ TP_ARGS(dp, parent_ino)) DEFINE_XREP_DIR_CLASS(xrep_dir_rebuild_tree); DEFINE_XREP_DIR_CLASS(xrep_dir_reset_fork); +DEFINE_XREP_DIR_CLASS(xrep_parent_reset_dir); DECLARE_EVENT_CLASS(xrep_dirent_class, TP_PROTO(struct xfs_inode *dp, struct xfs_name *name, xfs_ino_t ino), @@ -2503,6 +2504,7 @@ DEFINE_EVENT(xrep_parent_salvage_class, name, \ TP_PROTO(struct xfs_inode *dp, xfs_ino_t ino), \ TP_ARGS(dp, ino)) DEFINE_XREP_PARENT_SALVAGE_CLASS(xrep_dir_salvaged_parent); +DEFINE_XREP_PARENT_SALVAGE_CLASS(xrep_findparent_dirent); #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */ |