* [PATCH 1/4] xfs: online repair of directories
2024-02-27 2:18 [PATCHSET v29.4 09/13] xfs: online repair of directories Darrick J. Wong
@ 2024-02-27 2:31 ` Darrick J. Wong
2024-02-28 17:16 ` Christoph Hellwig
2024-02-27 2:31 ` [PATCH 2/4] xfs: scan the filesystem to repair a directory dotdot entry Darrick J. Wong
` (2 subsequent siblings)
3 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-02-27 2:31 UTC (permalink / raw)
To: djwong; +Cc: linux-xfs, hch
From: Darrick J. Wong <djwong@kernel.org>
If a directory looks like it's in bad shape, try to sift through the
rubble to find whatever directory entries we can, scan the directory
tree for the parent (if needed), stage the new directory contents in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk. As a side effect of this patch, directory
inactivation will be able to purge any leftover dir blocks.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/Makefile | 1
fs/xfs/scrub/dir.c | 9
fs/xfs/scrub/dir_repair.c | 1351 ++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/inode_repair.c | 5
fs/xfs/scrub/nlinks.c | 23 +
fs/xfs/scrub/nlinks_repair.c | 9
fs/xfs/scrub/parent.c | 4
fs/xfs/scrub/readdir.c | 7
fs/xfs/scrub/repair.c | 1
fs/xfs/scrub/repair.h | 4
fs/xfs/scrub/scrub.c | 2
fs/xfs/scrub/tempfile.c | 13
fs/xfs/scrub/tempfile.h | 2
fs/xfs/scrub/trace.h | 112 +++
fs/xfs/xfs_inode.c | 51 ++
15 files changed, 1592 insertions(+), 2 deletions(-)
create mode 100644 fs/xfs/scrub/dir_repair.c
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 7c2f4ba3335ec..cdb2ee814300d 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -199,6 +199,7 @@ xfs-y += $(addprefix scrub/, \
attr_repair.o \
bmap_repair.o \
cow_repair.o \
+ dir_repair.o \
fscounters_repair.o \
ialloc_repair.o \
inode_repair.o \
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 7bac74621af77..3fe6ffcf9c062 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -21,12 +21,21 @@
#include "scrub/dabtree.h"
#include "scrub/readdir.h"
#include "scrub/health.h"
+#include "scrub/repair.h"
/* Set us up to scrub directories. */
int
xchk_setup_directory(
struct xfs_scrub *sc)
{
+ int error;
+
+ if (xchk_could_repair(sc)) {
+ error = xrep_setup_directory(sc);
+ if (error)
+ return error;
+ }
+
return xchk_setup_inode_contents(sc, 0);
}
diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c
new file mode 100644
index 0000000000000..959b921752e84
--- /dev/null
+++ b/fs/xfs/scrub/dir_repair.c
@@ -0,0 +1,1351 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 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_dir2_priv.h"
+#include "xfs_bmap.h"
+#include "xfs_quota.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_trans_space.h"
+#include "xfs_bmap_util.h"
+#include "xfs_exchmaps.h"
+#include "xfs_exchrange.h"
+#include "xfs_ag.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/tempfile.h"
+#include "scrub/tempexch.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/xfblob.h"
+#include "scrub/readdir.h"
+#include "scrub/reap.h"
+
+/*
+ * Directory Repair
+ * ================
+ *
+ * We repair directories by reading the directory data blocks looking for
+ * directory entries that look salvageable (name passes verifiers, entry points
+ * to a valid allocated inode, etc). Each entry worth salvaging is stashed in
+ * memory, and the stashed entries are periodically replayed into a temporary
+ * directory to constrain memory use. Batching the construction of the
+ * temporary directory in this fashion reduces lock cycling of the directory
+ * being repaired and the temporary directory, and will later become important
+ * for parent pointer scanning.
+ *
+ * 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 mapping exchange
+ * is used to commit the new directory blocks to the directory being repaired.
+ * This will disrupt readdir cursors.
+ *
+ * Legacy Locking Issues
+ * ---------------------
+ *
+ * Prior to Linux 6.5, if /a, /a/b, and /c were all directories, the VFS would
+ * not take i_rwsem on /a/b for a "mv /a/b /c/" operation. This meant that
+ * only b's ILOCK protected b's dotdot update. b's IOLOCK was not taken,
+ * unlike every other dotdot update (link, remove, mkdir). If the repair code
+ * dropped the ILOCK, we it was required either to revalidate the dotdot entry
+ * or to use dirent hooks to capture updates from other threads.
+ */
+
+/* Directory entry to be restored in the new directory. */
+struct xrep_dirent {
+ /* Cookie for retrieval of the dirent name. */
+ xfblob_cookie name_cookie;
+
+ /* Target inode number. */
+ xfs_ino_t ino;
+
+ /* Length of the dirent name. */
+ uint8_t namelen;
+
+ /* File type of the dirent. */
+ uint8_t ftype;
+};
+
+/*
+ * Stash up to 8 pages of recovered dirent data in dir_entries and dir_names
+ * before we write them to the temp dir.
+ */
+#define XREP_DIR_MAX_STASH_BYTES (PAGE_SIZE * 8)
+
+struct xrep_dir {
+ struct xfs_scrub *sc;
+
+ /* Fixed-size array of xrep_dirent structures. */
+ struct xfarray *dir_entries;
+
+ /* Blobs containing directory entry names. */
+ struct xfblob *dir_names;
+
+ /* Information for exchanging data forks at the end. */
+ struct xrep_tempexch tx;
+
+ /* Preallocated args struct for performing dir operations */
+ struct xfs_da_args args;
+
+ /*
+ * This is the parent that we're going to set on the reconstructed
+ * directory.
+ */
+ xfs_ino_t parent_ino;
+
+ /* How many subdirectories did we find? */
+ uint64_t subdirs;
+
+ /* How many dirents did we find? */
+ unsigned int dirents;
+
+ /* Directory entry name, plus the trailing null. */
+ unsigned char namebuf[MAXNAMELEN];
+};
+
+/* Tear down all the incore stuff we created. */
+static void
+xrep_dir_teardown(
+ struct xfs_scrub *sc)
+{
+ struct xrep_dir *rd = sc->buf;
+
+ xfblob_destroy(rd->dir_names);
+ xfarray_destroy(rd->dir_entries);
+}
+
+/* Set up for a directory repair. */
+int
+xrep_setup_directory(
+ struct xfs_scrub *sc)
+{
+ struct xrep_dir *rd;
+ int error;
+
+ error = xrep_tempfile_create(sc, S_IFDIR);
+ if (error)
+ return error;
+
+ rd = kvzalloc(sizeof(struct xrep_dir), XCHK_GFP_FLAGS);
+ if (!rd)
+ return -ENOMEM;
+ rd->sc = sc;
+ sc->buf = rd;
+
+ 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.
+ */
+static inline xfs_ino_t
+xrep_dir_self_parent(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->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;
+}
+
+/*
+ * 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)
+{
+ struct xfs_scrub *sc = rd->sc;
+ xfs_ino_t ino;
+ int error;
+
+ error = xfs_dir_lookup(sc->tp, sc->ip, &xfs_name_dotdot, &ino, NULL);
+ if (error)
+ return NULLFSINO;
+ if (!xfs_verify_dir_ino(sc->mp, ino))
+ return NULLFSINO;
+
+ return ino;
+}
+
+/*
+ * 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.
+ */
+STATIC int
+xrep_dir_find_parent(
+ struct xrep_dir *rd)
+{
+ xfs_ino_t ino;
+
+ ino = xrep_dir_self_parent(rd);
+ if (ino != NULLFSINO) {
+ rd->parent_ino = ino;
+ return 0;
+ }
+
+ ino = xrep_dir_lookup_parent(rd);
+ if (ino != NULLFSINO) {
+ rd->parent_ino = ino;
+ return 0;
+ }
+
+ /* NOTE: A future patch will deal with moving orphans. */
+ return -EFSCORRUPTED;
+}
+
+/*
+ * Decide if we want to salvage this entry. We don't bother with oversized
+ * names or the dot entry.
+ */
+STATIC int
+xrep_dir_want_salvage(
+ struct xrep_dir *rd,
+ const char *name,
+ int namelen,
+ xfs_ino_t ino)
+{
+ struct xfs_mount *mp = rd->sc->mp;
+
+ /* No pointers to ourselves or to garbage. */
+ if (ino == rd->sc->ip->i_ino)
+ return false;
+ if (!xfs_verify_dir_ino(mp, ino))
+ return false;
+
+ /* No weird looking names or dot entries. */
+ if (namelen >= MAXNAMELEN || namelen <= 0)
+ return false;
+ if (namelen == 1 && name[0] == '.')
+ return false;
+
+ return true;
+}
+
+/*
+ * Remember that we want to create a dirent in the tempdir. These stashed
+ * actions will be replayed later.
+ */
+STATIC int
+xrep_dir_stash_createname(
+ struct xrep_dir *rd,
+ const struct xfs_name *name,
+ xfs_ino_t ino)
+{
+ struct xrep_dirent dirent = {
+ .ino = ino,
+ .namelen = name->len,
+ .ftype = name->type,
+ };
+ int error;
+
+ trace_xrep_dir_stash_createname(rd->sc->tempip, name, ino);
+
+ error = xfblob_store(rd->dir_names, &dirent.name_cookie, name->name,
+ name->len);
+ if (error)
+ return error;
+
+ return xfarray_append(rd->dir_entries, &dirent);
+}
+
+/* Allocate an in-core record to hold entries while we rebuild the dir data. */
+STATIC int
+xrep_dir_salvage_entry(
+ struct xrep_dir *rd,
+ unsigned char *name,
+ unsigned int namelen,
+ xfs_ino_t ino)
+{
+ struct xfs_name xname = {
+ .name = name,
+ };
+ struct xfs_scrub *sc = rd->sc;
+ struct xfs_inode *ip;
+ unsigned int i = 0;
+ int error = 0;
+
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ /*
+ * Truncate the name to the first character that would trip namecheck.
+ * If we no longer have a name after that, ignore this entry.
+ */
+ while (i < namelen && name[i] != 0 && name[i] != '/')
+ i++;
+ if (i == 0)
+ return 0;
+ xname.len = i;
+
+ /* Ignore '..' entries; we already picked the new parent. */
+ if (xname.len == 2 && name[0] == '.' && name[1] == '.') {
+ trace_xrep_dir_salvaged_parent(sc->ip, ino);
+ return 0;
+ }
+
+ trace_xrep_dir_salvage_entry(sc->ip, &xname, ino);
+
+ /*
+ * Compute the ftype or dump the entry if we can't. We don't lock the
+ * inode because inodes can't change type while we have a reference.
+ */
+ error = xchk_iget(sc, ino, &ip);
+ if (error)
+ return 0;
+
+ xname.type = xfs_mode_to_ftype(VFS_I(ip)->i_mode);
+ xchk_irele(sc, ip);
+
+ return xrep_dir_stash_createname(rd, &xname, ino);
+}
+
+/* Record a shortform directory entry for later reinsertion. */
+STATIC int
+xrep_dir_salvage_sf_entry(
+ struct xrep_dir *rd,
+ struct xfs_dir2_sf_hdr *sfp,
+ struct xfs_dir2_sf_entry *sfep)
+{
+ xfs_ino_t ino;
+
+ ino = xfs_dir2_sf_get_ino(rd->sc->mp, sfp, sfep);
+ if (!xrep_dir_want_salvage(rd, sfep->name, sfep->namelen, ino))
+ return 0;
+
+ return xrep_dir_salvage_entry(rd, sfep->name, sfep->namelen, ino);
+}
+
+/* Record a regular directory entry for later reinsertion. */
+STATIC int
+xrep_dir_salvage_data_entry(
+ struct xrep_dir *rd,
+ struct xfs_dir2_data_entry *dep)
+{
+ xfs_ino_t ino;
+
+ ino = be64_to_cpu(dep->inumber);
+ if (!xrep_dir_want_salvage(rd, dep->name, dep->namelen, ino))
+ return 0;
+
+ return xrep_dir_salvage_entry(rd, dep->name, dep->namelen, ino);
+}
+
+/* Try to recover block/data format directory entries. */
+STATIC int
+xrep_dir_recover_data(
+ struct xrep_dir *rd,
+ struct xfs_buf *bp)
+{
+ struct xfs_da_geometry *geo = rd->sc->mp->m_dir_geo;
+ unsigned int offset;
+ unsigned int end;
+ int error = 0;
+
+ /*
+ * Loop over the data portion of the block.
+ * Each object is a real entry (dep) or an unused one (dup).
+ */
+ offset = geo->data_entry_offset;
+ end = min_t(unsigned int, BBTOB(bp->b_length),
+ xfs_dir3_data_end_offset(geo, bp->b_addr));
+
+ while (offset < end) {
+ struct xfs_dir2_data_unused *dup = bp->b_addr + offset;
+ struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
+
+ if (xchk_should_terminate(rd->sc, &error))
+ return error;
+
+ /* Skip unused entries. */
+ if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
+ offset += be16_to_cpu(dup->length);
+ continue;
+ }
+
+ /* Don't walk off the end of the block. */
+ offset += xfs_dir2_data_entsize(rd->sc->mp, dep->namelen);
+ if (offset > end)
+ break;
+
+ /* Ok, let's save this entry. */
+ error = xrep_dir_salvage_data_entry(rd, dep);
+ if (error)
+ return error;
+
+ }
+
+ return 0;
+}
+
+/* Try to recover shortform directory entries. */
+STATIC int
+xrep_dir_recover_sf(
+ struct xrep_dir *rd)
+{
+ struct xfs_dir2_sf_hdr *hdr;
+ struct xfs_dir2_sf_entry *sfep;
+ struct xfs_dir2_sf_entry *next;
+ struct xfs_ifork *ifp;
+ xfs_ino_t ino;
+ unsigned char *end;
+ int error = 0;
+
+ ifp = xfs_ifork_ptr(rd->sc->ip, XFS_DATA_FORK);
+ hdr = ifp->if_data;
+ end = (unsigned char *)ifp->if_data + ifp->if_bytes;
+
+ ino = xfs_dir2_sf_get_parent_ino(hdr);
+ trace_xrep_dir_salvaged_parent(rd->sc->ip, ino);
+
+ sfep = xfs_dir2_sf_firstentry(hdr);
+ while ((unsigned char *)sfep < end) {
+ if (xchk_should_terminate(rd->sc, &error))
+ return error;
+
+ next = xfs_dir2_sf_nextentry(rd->sc->mp, hdr, sfep);
+ if ((unsigned char *)next > end)
+ break;
+
+ /* Ok, let's save this entry. */
+ error = xrep_dir_salvage_sf_entry(rd, hdr, sfep);
+ if (error)
+ return error;
+
+ sfep = next;
+ }
+
+ return 0;
+}
+
+/*
+ * Try to figure out the format of this directory from the data fork mappings
+ * and the directory size. If we can be reasonably sure of format, we can be
+ * more aggressive in salvaging directory entries. On return, @magic_guess
+ * will be set to DIR3_BLOCK_MAGIC if we think this is a "block format"
+ * directory; DIR3_DATA_MAGIC if we think this is a "data format" directory,
+ * and 0 if we can't tell.
+ */
+STATIC void
+xrep_dir_guess_format(
+ struct xrep_dir *rd,
+ __be32 *magic_guess)
+{
+ struct xfs_inode *dp = rd->sc->ip;
+ struct xfs_mount *mp = rd->sc->mp;
+ struct xfs_da_geometry *geo = mp->m_dir_geo;
+ xfs_fileoff_t last;
+ int error;
+
+ ASSERT(xfs_has_crc(mp));
+
+ *magic_guess = 0;
+
+ /*
+ * If there's a single directory block and the directory size is
+ * exactly one block, this has to be a single block format directory.
+ */
+ error = xfs_bmap_last_offset(dp, &last, XFS_DATA_FORK);
+ if (!error && XFS_FSB_TO_B(mp, last) == geo->blksize &&
+ dp->i_disk_size == geo->blksize) {
+ *magic_guess = cpu_to_be32(XFS_DIR3_BLOCK_MAGIC);
+ return;
+ }
+
+ /*
+ * If the last extent before the leaf offset matches the directory
+ * size and the directory size is larger than 1 block, this is a
+ * data format directory.
+ */
+ last = geo->leafblk;
+ error = xfs_bmap_last_before(rd->sc->tp, dp, &last, XFS_DATA_FORK);
+ if (!error &&
+ XFS_FSB_TO_B(mp, last) > geo->blksize &&
+ XFS_FSB_TO_B(mp, last) == dp->i_disk_size) {
+ *magic_guess = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
+ return;
+ }
+}
+
+/* Recover directory entries from a specific directory block. */
+STATIC int
+xrep_dir_recover_dirblock(
+ struct xrep_dir *rd,
+ __be32 magic_guess,
+ xfs_dablk_t dabno)
+{
+ struct xfs_dir2_data_hdr *hdr;
+ struct xfs_buf *bp;
+ __be32 oldmagic;
+ int error;
+
+ /*
+ * Try to read buffer. We invalidate them in the next step so we don't
+ * bother to set a buffer type or ops.
+ */
+ error = xfs_da_read_buf(rd->sc->tp, rd->sc->ip, dabno,
+ XFS_DABUF_MAP_HOLE_OK, &bp, XFS_DATA_FORK, NULL);
+ if (error || !bp)
+ return error;
+
+ hdr = bp->b_addr;
+ oldmagic = hdr->magic;
+
+ trace_xrep_dir_recover_dirblock(rd->sc->ip, dabno,
+ be32_to_cpu(hdr->magic), be32_to_cpu(magic_guess));
+
+ /*
+ * If we're sure of the block's format, proceed with the salvage
+ * operation using the specified magic number.
+ */
+ if (magic_guess) {
+ hdr->magic = magic_guess;
+ goto recover;
+ }
+
+ /*
+ * If we couldn't guess what type of directory this is, then we will
+ * only salvage entries from directory blocks that match the magic
+ * number and pass verifiers.
+ */
+ switch (hdr->magic) {
+ case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
+ case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
+ if (!xrep_buf_verify_struct(bp, &xfs_dir3_block_buf_ops))
+ goto out;
+ if (xfs_dir3_block_header_check(bp, rd->sc->ip->i_ino) != NULL)
+ goto out;
+ break;
+ case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
+ case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
+ if (!xrep_buf_verify_struct(bp, &xfs_dir3_data_buf_ops))
+ goto out;
+ if (xfs_dir3_data_header_check(bp, rd->sc->ip->i_ino) != NULL)
+ goto out;
+ break;
+ default:
+ goto out;
+ }
+
+recover:
+ error = xrep_dir_recover_data(rd, bp);
+
+out:
+ hdr->magic = oldmagic;
+ xfs_trans_brelse(rd->sc->tp, bp);
+ return error;
+}
+
+static inline void
+xrep_dir_init_args(
+ struct xrep_dir *rd,
+ struct xfs_inode *dp,
+ const struct xfs_name *name)
+{
+ memset(&rd->args, 0, sizeof(struct xfs_da_args));
+ rd->args.geo = rd->sc->mp->m_dir_geo;
+ rd->args.whichfork = XFS_DATA_FORK;
+ rd->args.owner = rd->sc->ip->i_ino;
+ rd->args.trans = rd->sc->tp;
+ rd->args.dp = dp;
+ if (!name)
+ return;
+ rd->args.name = name->name;
+ rd->args.namelen = name->len;
+ rd->args.filetype = name->type;
+ rd->args.hashval = xfs_dir2_hashname(rd->sc->mp, name);
+}
+
+/* Replay a stashed createname into the temporary directory. */
+STATIC int
+xrep_dir_replay_createname(
+ struct xrep_dir *rd,
+ const struct xfs_name *name,
+ xfs_ino_t inum,
+ xfs_extlen_t total)
+{
+ struct xfs_scrub *sc = rd->sc;
+ struct xfs_inode *dp = rd->sc->tempip;
+ bool is_block, is_leaf;
+ int error;
+
+ ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
+
+ error = xfs_dir_ino_validate(sc->mp, inum);
+ if (error)
+ return error;
+
+ trace_xrep_dir_replay_createname(dp, name, inum);
+
+ xrep_dir_init_args(rd, dp, name);
+ rd->args.inumber = inum;
+ rd->args.total = total;
+ rd->args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
+
+ if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL)
+ return xfs_dir2_sf_addname(&rd->args);
+
+ error = xfs_dir2_isblock(&rd->args, &is_block);
+ if (error)
+ return error;
+ if (is_block)
+ return xfs_dir2_block_addname(&rd->args);
+
+ error = xfs_dir2_isleaf(&rd->args, &is_leaf);
+ if (error)
+ return error;
+ if (is_leaf)
+ return xfs_dir2_leaf_addname(&rd->args);
+
+ return xfs_dir2_node_addname(&rd->args);
+}
+
+/*
+ * Add this stashed incore directory entry to the temporary directory.
+ * The caller must hold the tempdir's IOLOCK, must not hold any ILOCKs, and
+ * must not be in transaction context.
+ */
+STATIC int
+xrep_dir_replay_update(
+ struct xrep_dir *rd,
+ const struct xrep_dirent *dirent)
+{
+ struct xfs_name name = {
+ .len = dirent->namelen,
+ .type = dirent->ftype,
+ .name = rd->namebuf,
+ };
+ struct xfs_mount *mp = rd->sc->mp;
+#ifdef DEBUG
+ xfs_ino_t ino;
+#endif
+ uint resblks;
+ int error;
+
+ resblks = XFS_LINK_SPACE_RES(mp, dirent->namelen);
+ error = xchk_trans_alloc(rd->sc, resblks);
+ if (error)
+ return error;
+
+ /* Lock the temporary directory and join it to the transaction */
+ xrep_tempfile_ilock(rd->sc);
+ xfs_trans_ijoin(rd->sc->tp, rd->sc->tempip, 0);
+
+ /*
+ * Create a replacement dirent in the temporary directory. Note that
+ * _createname doesn't check for existing entries. There shouldn't be
+ * any in the temporary dir, but we'll verify this in debug mode.
+ */
+#ifdef DEBUG
+ error = xchk_dir_lookup(rd->sc, rd->sc->tempip, &name, &ino);
+ if (error != -ENOENT) {
+ ASSERT(error != -ENOENT);
+ goto out_cancel;
+ }
+#endif
+
+ error = xrep_dir_replay_createname(rd, &name, dirent->ino, resblks);
+ if (error)
+ goto out_cancel;
+
+ if (name.type == XFS_DIR3_FT_DIR)
+ rd->subdirs++;
+ rd->dirents++;
+
+ /* Commit and unlock. */
+ error = xrep_trans_commit(rd->sc);
+ if (error)
+ return error;
+
+ xrep_tempfile_iunlock(rd->sc);
+ return 0;
+out_cancel:
+ xchk_trans_cancel(rd->sc);
+ xrep_tempfile_iunlock(rd->sc);
+ return error;
+}
+
+/*
+ * Flush stashed incore dirent updates that have been recorded by the scanner.
+ * This is done to reduce the memory requirements of the directory rebuild,
+ * since directories can contain up to 32GB of directory data.
+ *
+ * Caller must not hold transactions or ILOCKs. Caller must hold the tempdir
+ * IOLOCK.
+ */
+STATIC int
+xrep_dir_replay_updates(
+ struct xrep_dir *rd)
+{
+ xfarray_idx_t array_cur;
+ int error;
+
+ /* Add all the salvaged dirents to the temporary directory. */
+ foreach_xfarray_idx(rd->dir_entries, array_cur) {
+ struct xrep_dirent dirent;
+
+ error = xfarray_load(rd->dir_entries, array_cur, &dirent);
+ if (error)
+ return error;
+
+ /* The dirent name is stored in the in-core buffer. */
+ error = xfblob_load(rd->dir_names, dirent.name_cookie,
+ rd->namebuf, dirent.namelen);
+ if (error)
+ return error;
+ rd->namebuf[MAXNAMELEN - 1] = 0;
+
+ error = xrep_dir_replay_update(rd, &dirent);
+ if (error)
+ return error;
+ }
+
+ /* Empty out both arrays now that we've added the entries. */
+ xfarray_truncate(rd->dir_entries);
+ xfblob_truncate(rd->dir_names);
+ return 0;
+}
+
+/*
+ * Periodically flush stashed directory entries to the temporary dir. This
+ * is done to reduce the memory requirements of the directory rebuild, since
+ * directories can contain up to 32GB of directory data.
+ */
+STATIC int
+xrep_dir_flush_stashed(
+ struct xrep_dir *rd)
+{
+ int error;
+
+ /*
+ * Entering this function, the scrub context has a reference to the
+ * inode being repaired, the temporary file, and a scrub transaction
+ * that we use during dirent salvaging to avoid livelocking if there
+ * are cycles in the directory structures. We hold ILOCK_EXCL on both
+ * the inode being repaired and the temporary file, though they are
+ * not ijoined to the scrub transaction.
+ *
+ * To constrain kernel memory use, we occasionally write salvaged
+ * dirents from the xfarray and xfblob structures into the temporary
+ * directory in preparation for exchanging the directory structures at
+ * the end. Updating the temporary file requires a transaction, so we
+ * commit the scrub transaction and drop the two ILOCKs so that
+ * we can allocate whatever transaction we want.
+ *
+ * We still hold IOLOCK_EXCL on the inode being repaired, which
+ * prevents anyone from accessing the damaged directory data while we
+ * repair it.
+ */
+ error = xrep_trans_commit(rd->sc);
+ if (error)
+ return error;
+ xchk_iunlock(rd->sc, XFS_ILOCK_EXCL);
+
+ /*
+ * Take the IOLOCK of the temporary file while we modify dirents. This
+ * isn't strictly required because the temporary file is never revealed
+ * to userspace, but we follow the same locking rules. We still hold
+ * sc->ip's IOLOCK.
+ */
+ error = xrep_tempfile_iolock_polled(rd->sc);
+ if (error)
+ return error;
+
+ /* Write to the tempdir all the updates that we've stashed. */
+ error = xrep_dir_replay_updates(rd);
+ xrep_tempfile_iounlock(rd->sc);
+ if (error)
+ return error;
+
+ /*
+ * Recreate the salvage transaction and relock the dir we're salvaging.
+ */
+ error = xchk_trans_alloc(rd->sc, 0);
+ if (error)
+ return error;
+ xchk_ilock(rd->sc, XFS_ILOCK_EXCL);
+ return 0;
+}
+
+/* Decide if we've stashed too much dirent data in memory. */
+static inline bool
+xrep_dir_want_flush_stashed(
+ struct xrep_dir *rd)
+{
+ unsigned long long bytes;
+
+ bytes = xfarray_bytes(rd->dir_entries) + xfblob_bytes(rd->dir_names);
+ return bytes > XREP_DIR_MAX_STASH_BYTES;
+}
+
+/* Extract as many directory entries as we can. */
+STATIC int
+xrep_dir_recover(
+ struct xrep_dir *rd)
+{
+ struct xfs_bmbt_irec got;
+ struct xfs_scrub *sc = rd->sc;
+ struct xfs_da_geometry *geo = sc->mp->m_dir_geo;
+ xfs_fileoff_t offset;
+ xfs_dablk_t dabno;
+ __be32 magic_guess;
+ int nmap;
+ int error;
+
+ xrep_dir_guess_format(rd, &magic_guess);
+
+ /* Iterate each directory data block in the data fork. */
+ for (offset = 0;
+ offset < geo->leafblk;
+ offset = got.br_startoff + got.br_blockcount) {
+ nmap = 1;
+ error = xfs_bmapi_read(sc->ip, offset, geo->leafblk - offset,
+ &got, &nmap, 0);
+ if (error)
+ return error;
+ if (nmap != 1)
+ return -EFSCORRUPTED;
+ if (!xfs_bmap_is_written_extent(&got))
+ continue;
+
+ for (dabno = round_up(got.br_startoff, geo->fsbcount);
+ dabno < got.br_startoff + got.br_blockcount;
+ dabno += geo->fsbcount) {
+ if (xchk_should_terminate(rd->sc, &error))
+ return error;
+
+ error = xrep_dir_recover_dirblock(rd,
+ magic_guess, dabno);
+ if (error)
+ return error;
+
+ /* Flush dirents to constrain memory usage. */
+ if (xrep_dir_want_flush_stashed(rd)) {
+ error = xrep_dir_flush_stashed(rd);
+ if (error)
+ return error;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Find all the directory entries for this inode by scraping them out of the
+ * directory leaf blocks by hand, and flushing them into the temp dir.
+ */
+STATIC int
+xrep_dir_find_entries(
+ struct xrep_dir *rd)
+{
+ struct xfs_inode *dp = rd->sc->ip;
+ int error;
+
+ /*
+ * Salvage directory entries from the old directory, and write them to
+ * the temporary directory.
+ */
+ if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
+ error = xrep_dir_recover_sf(rd);
+ } else {
+ error = xfs_iread_extents(rd->sc->tp, dp, XFS_DATA_FORK);
+ if (error)
+ return error;
+
+ error = xrep_dir_recover(rd);
+ }
+ if (error)
+ return error;
+
+ return xrep_dir_flush_stashed(rd);
+}
+
+/* Scan all files in the filesystem for dirents. */
+STATIC int
+xrep_dir_salvage_entries(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ int error;
+
+ /*
+ * Drop the ILOCK on this directory so that we can scan for this
+ * directory's parent. Figure out who is going to be the parent of
+ * this directory, then retake the ILOCK so that we can salvage
+ * directory entries.
+ */
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+ error = xrep_dir_find_parent(rd);
+ xchk_ilock(sc, XFS_ILOCK_EXCL);
+ if (error)
+ return error;
+
+ /*
+ * Collect directory entries by parsing raw leaf blocks to salvage
+ * whatever we can. When we're done, free the staging memory before
+ * exchanging the directories to reduce memory usage.
+ */
+ error = xrep_dir_find_entries(rd);
+ if (error)
+ return error;
+
+ /*
+ * Cancel the repair transaction and drop the ILOCK so that we can
+ * (later) use the atomic mapping exchange functions to compute the
+ * correct block reservations and re-lock the inodes.
+ *
+ * We still hold IOLOCK_EXCL (aka i_rwsem) which will prevent directory
+ * modifications, but there's nothing to prevent userspace from reading
+ * the directory until we're ready for the exchange operation. Reads
+ * will return -EIO without shutting down the fs, so we're ok with
+ * that.
+ */
+ error = xrep_trans_commit(sc);
+ if (error)
+ return error;
+
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+ 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
+ * joined to a clean scrub transaction.
+ */
+STATIC int
+xrep_dir_reset_fork(
+ struct xrep_dir *rd,
+ xfs_ino_t parent_ino)
+{
+ struct xfs_scrub *sc = rd->sc;
+ struct xfs_ifork *ifp = xfs_ifork_ptr(sc->tempip, XFS_DATA_FORK);
+ int error;
+
+ /* Unmap all the directory buffers. */
+ if (xfs_ifork_has_extents(ifp)) {
+ error = xrep_reap_ifork(sc, sc->tempip, XFS_DATA_FORK);
+ if (error)
+ return error;
+ }
+
+ trace_xrep_dir_reset_fork(sc->tempip, parent_ino);
+
+ /* Reset the data fork to an empty data fork. */
+ xfs_idestroy_fork(ifp);
+ ifp->if_bytes = 0;
+ sc->tempip->i_disk_size = 0;
+
+ /* Reinitialize the short form directory. */
+ xrep_dir_init_args(rd, sc->tempip, NULL);
+ return xfs_dir2_sf_create(&rd->args, parent_ino);
+}
+
+/*
+ * Prepare both inodes' directory forks for exchanging mappings. Promote the
+ * tempfile from short format to leaf format, and if the file being repaired
+ * has a short format data fork, turn it into an empty extent list.
+ */
+STATIC int
+xrep_dir_swap_prep(
+ struct xfs_scrub *sc,
+ bool temp_local,
+ bool ip_local)
+{
+ int error;
+
+ /*
+ * If the tempfile's directory is in shortform format, convert that to
+ * a single leaf extent so that we can use the atomic mapping exchange.
+ */
+ if (temp_local) {
+ struct xfs_da_args args = {
+ .dp = sc->tempip,
+ .geo = sc->mp->m_dir_geo,
+ .whichfork = XFS_DATA_FORK,
+ .trans = sc->tp,
+ .total = 1,
+ .owner = sc->ip->i_ino,
+ };
+
+ error = xfs_dir2_sf_to_block(&args);
+ if (error)
+ return error;
+
+ /*
+ * Roll the deferred log items to get us back to a clean
+ * transaction.
+ */
+ error = xfs_defer_finish(&sc->tp);
+ if (error)
+ return error;
+ }
+
+ /*
+ * If the file being repaired had a shortform data fork, convert that
+ * to an empty extent list in preparation for the atomic mapping
+ * exchange.
+ */
+ if (ip_local) {
+ struct xfs_ifork *ifp;
+
+ ifp = xfs_ifork_ptr(sc->ip, XFS_DATA_FORK);
+ xfs_idestroy_fork(ifp);
+ ifp->if_format = XFS_DINODE_FMT_EXTENTS;
+ ifp->if_nextents = 0;
+ ifp->if_bytes = 0;
+ ifp->if_data = NULL;
+ ifp->if_height = 0;
+
+ xfs_trans_log_inode(sc->tp, sc->ip,
+ XFS_ILOG_CORE | XFS_ILOG_DDATA);
+ }
+
+ return 0;
+}
+
+/*
+ * Replace the inode number of a directory entry.
+ */
+static int
+xrep_dir_replace(
+ struct xrep_dir *rd,
+ struct xfs_inode *dp,
+ const struct xfs_name *name,
+ xfs_ino_t inum,
+ xfs_extlen_t total)
+{
+ struct xfs_scrub *sc = rd->sc;
+ bool is_block, is_leaf;
+ int error;
+
+ ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
+
+ error = xfs_dir_ino_validate(sc->mp, inum);
+ if (error)
+ return error;
+
+ xrep_dir_init_args(rd, dp, name);
+ rd->args.inumber = inum;
+ rd->args.total = total;
+
+ if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL)
+ return xfs_dir2_sf_replace(&rd->args);
+
+ error = xfs_dir2_isblock(&rd->args, &is_block);
+ if (error)
+ return error;
+ if (is_block)
+ return xfs_dir2_block_replace(&rd->args);
+
+ error = xfs_dir2_isleaf(&rd->args, &is_leaf);
+ if (error)
+ return error;
+ if (is_leaf)
+ return xfs_dir2_leaf_replace(&rd->args);
+
+ return xfs_dir2_node_replace(&rd->args);
+}
+
+/*
+ * Reset the link count of this directory and adjust the unlinked list pointers
+ * as needed.
+ */
+STATIC int
+xrep_dir_set_nlink(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ struct xfs_inode *dp = sc->ip;
+ struct xfs_perag *pag;
+ unsigned int new_nlink = rd->subdirs + 2;
+ int error;
+
+ /*
+ * The directory is not on the incore unlinked list, which means that
+ * it needs to be reachable via the directory tree. Update the nlink
+ * with our observed link count.
+ *
+ * XXX: A subsequent patch will handle parentless directories by moving
+ * them to the lost and found instead of aborting the repair.
+ */
+ if (!xfs_inode_on_unlinked_list(dp))
+ goto reset_nlink;
+
+ /*
+ * The directory is on the unlinked list and we did not find any
+ * dirents. Set the link count to zero and let the directory
+ * inactivate when the last reference drops.
+ */
+ if (rd->dirents == 0) {
+ new_nlink = 0;
+ goto reset_nlink;
+ }
+
+ /*
+ * The directory is on the unlinked list and we found dirents. This
+ * directory needs to be reachable via the directory tree. Remove the
+ * dir from the unlinked list and update nlink with the observed link
+ * count.
+ */
+ pag = xfs_perag_get(sc->mp, XFS_INO_TO_AGNO(sc->mp, dp->i_ino));
+ if (!pag) {
+ ASSERT(0);
+ return -EFSCORRUPTED;
+ }
+
+ error = xfs_iunlink_remove(sc->tp, pag, dp);
+ xfs_perag_put(pag);
+ if (error)
+ return error;
+
+reset_nlink:
+ if (VFS_I(dp)->i_nlink != new_nlink)
+ set_nlink(VFS_I(dp), new_nlink);
+ return 0;
+}
+
+/* Exchange the temporary directory's data fork with the one being repaired. */
+STATIC int
+xrep_dir_swap(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ bool ip_local, temp_local;
+ int error = 0;
+
+ /*
+ * If we found enough subdirs to overflow this directory's link count,
+ * bail out to userspace before we modify anything.
+ */
+ if (rd->subdirs + 2 > XFS_MAXLINK)
+ return -EFSCORRUPTED;
+
+ /*
+ * Reset the temporary directory's '..' entry to point to the parent
+ * that we found. The temporary directory was created with the root
+ * directory as the parent, so we can skip this if repairing a
+ * subdirectory of the root.
+ *
+ * It's also possible that this replacement could also expand a sf
+ * tempdir into block format.
+ */
+ if (rd->parent_ino != sc->mp->m_rootip->i_ino) {
+ error = xrep_dir_replace(rd, rd->sc->tempip, &xfs_name_dotdot,
+ rd->parent_ino, rd->tx.req.resblks);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Changing the dot and dotdot entries could have changed the shape of
+ * the directory, so we recompute these.
+ */
+ ip_local = sc->ip->i_df.if_format == XFS_DINODE_FMT_LOCAL;
+ temp_local = sc->tempip->i_df.if_format == XFS_DINODE_FMT_LOCAL;
+
+ /*
+ * If the both files have a local format data fork and the rebuilt
+ * directory data would fit in the repaired file's data fork, copy
+ * the contents from the tempfile and update the directory link count.
+ * We're done now.
+ */
+ if (ip_local && temp_local &&
+ sc->tempip->i_disk_size <= xfs_inode_data_fork_size(sc->ip)) {
+ xrep_tempfile_copyout_local(sc, XFS_DATA_FORK);
+ return xrep_dir_set_nlink(rd);
+ }
+
+ /*
+ * Clean the transaction before we start working on exchanging
+ * directory contents.
+ */
+ error = xrep_tempfile_roll_trans(rd->sc);
+ if (error)
+ return error;
+
+ /* Otherwise, make sure both data forks are in block-mapping mode. */
+ error = xrep_dir_swap_prep(sc, temp_local, ip_local);
+ if (error)
+ return error;
+
+ /*
+ * Set nlink of the directory in the same transaction sequence that
+ * (atomically) commits the new directory data.
+ */
+ error = xrep_dir_set_nlink(rd);
+ if (error)
+ return error;
+
+ return xrep_tempexch_contents(sc, &rd->tx);
+}
+
+/*
+ * Exchange the new directory contents (which we created in the tempfile) with
+ * the directory being repaired.
+ */
+STATIC int
+xrep_dir_rebuild_tree(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ int error;
+
+ trace_xrep_dir_rebuild_tree(sc->ip, rd->parent_ino);
+
+ /*
+ * Take the IOLOCK on the temporary file so that we can run dir
+ * operations with the same locks held as we would for a normal file.
+ * We still hold sc->ip's IOLOCK.
+ */
+ error = xrep_tempfile_iolock_polled(rd->sc);
+ if (error)
+ return error;
+
+ /* Allocate transaction and ILOCK the scrub file and the temp file. */
+ error = xrep_tempexch_trans_alloc(sc, XFS_DATA_FORK, &rd->tx);
+ if (error)
+ return error;
+
+ /*
+ * Exchange the tempdir's data fork with the file being repaired. This
+ * recreates the transaction and re-takes the ILOCK in the scrub
+ * context.
+ */
+ error = xrep_dir_swap(rd);
+ if (error)
+ return error;
+
+ /*
+ * Release the old directory blocks and reset the data fork of the temp
+ * directory to an empty shortform directory because inactivation does
+ * nothing for directories.
+ */
+ error = xrep_dir_reset_fork(rd, sc->mp->m_rootip->i_ino);
+ if (error)
+ return error;
+
+ /*
+ * Roll to get a transaction without any inodes joined to it. Then we
+ * can drop the tempfile's ILOCK and IOLOCK before doing more work on
+ * the scrub target directory.
+ */
+ error = xfs_trans_roll(&sc->tp);
+ if (error)
+ return error;
+
+ xrep_tempfile_iunlock(sc);
+ xrep_tempfile_iounlock(sc);
+ return 0;
+}
+
+/* Set up the filesystem scan so we can regenerate directory entries. */
+STATIC int
+xrep_dir_setup_scan(
+ struct xrep_dir *rd)
+{
+ struct xfs_scrub *sc = rd->sc;
+ char *descr;
+ int error;
+
+ rd->parent_ino = NULLFSINO;
+
+ /* Set up some staging memory for salvaging dirents. */
+ descr = xchk_xfile_ino_descr(sc, "directory entries");
+ error = xfarray_create(descr, 0, sizeof(struct xrep_dirent),
+ &rd->dir_entries);
+ kfree(descr);
+ if (error)
+ return error;
+
+ descr = xchk_xfile_ino_descr(sc, "directory entry names");
+ error = xfblob_create(descr, &rd->dir_names);
+ kfree(descr);
+ if (error)
+ goto out_xfarray;
+
+ return 0;
+
+out_xfarray:
+ xfarray_destroy(rd->dir_entries);
+ rd->dir_entries = NULL;
+ return error;
+}
+
+/*
+ * Repair the directory metadata.
+ *
+ * XXX: Directory entry buffers can be multiple fsblocks in size. The buffer
+ * cache in XFS can't handle aliased multiblock buffers, so this might
+ * misbehave if the directory blocks are crosslinked with other filesystem
+ * metadata.
+ *
+ * XXX: Is it necessary to check the dcache for this directory to make sure
+ * that we always recreate every cached entry?
+ */
+int
+xrep_directory(
+ struct xfs_scrub *sc)
+{
+ struct xrep_dir *rd = sc->buf;
+ int error;
+
+ /* The rmapbt is required to reap the old data fork. */
+ if (!xfs_has_rmapbt(sc->mp))
+ return -EOPNOTSUPP;
+
+ error = xrep_dir_setup_scan(rd);
+ if (error)
+ return error;
+
+ error = xrep_dir_salvage_entries(rd);
+ if (error)
+ goto out_teardown;
+
+ /* Last chance to abort before we start committing fixes. */
+ if (xchk_should_terminate(sc, &error))
+ goto out_teardown;
+
+ error = xrep_dir_rebuild_tree(rd);
+ if (error)
+ goto out_teardown;
+
+out_teardown:
+ xrep_dir_teardown(sc);
+ return error;
+}
diff --git a/fs/xfs/scrub/inode_repair.c b/fs/xfs/scrub/inode_repair.c
index 2105026d178a2..00d08eef32525 100644
--- a/fs/xfs/scrub/inode_repair.c
+++ b/fs/xfs/scrub/inode_repair.c
@@ -46,6 +46,7 @@
#include "scrub/repair.h"
#include "scrub/iscan.h"
#include "scrub/readdir.h"
+#include "scrub/tempfile.h"
/*
* Inode Record Repair
@@ -295,6 +296,10 @@ xrep_dinode_findmode_walk_directory(
unsigned int lock_mode;
int error = 0;
+ /* Ignore temporary repair directories. */
+ if (xrep_is_tempfile(dp))
+ return 0;
+
/*
* Scan the directory to see if there it contains an entry pointing to
* the directory that we are repairing.
diff --git a/fs/xfs/scrub/nlinks.c b/fs/xfs/scrub/nlinks.c
index 8a7d9557897cb..8b9aa73093d66 100644
--- a/fs/xfs/scrub/nlinks.c
+++ b/fs/xfs/scrub/nlinks.c
@@ -27,6 +27,7 @@
#include "scrub/nlinks.h"
#include "scrub/trace.h"
#include "scrub/readdir.h"
+#include "scrub/tempfile.h"
/*
* Live Inode Link Count Checking
@@ -152,6 +153,13 @@ xchk_nlinks_live_update(
xnc = container_of(nb, struct xchk_nlink_ctrs, dhook.dirent_hook.nb);
+ /*
+ * Ignore temporary directories being used to stage dir repairs, since
+ * we don't bump the link counts of the children.
+ */
+ if (xrep_is_tempfile(p->dp))
+ return NOTIFY_DONE;
+
trace_xchk_nlinks_live_update(xnc->sc->mp, p->dp, action, p->ip->i_ino,
p->delta, p->name->name, p->name->len);
@@ -303,6 +311,13 @@ xchk_nlinks_collect_dir(
unsigned int lock_mode;
int error = 0;
+ /*
+ * Ignore temporary directories being used to stage dir repairs, since
+ * we don't bump the link counts of the children.
+ */
+ if (xrep_is_tempfile(dp))
+ return 0;
+
/* Prevent anyone from changing this directory while we walk it. */
xfs_ilock(dp, XFS_IOLOCK_SHARED);
lock_mode = xfs_ilock_data_map_shared(dp);
@@ -537,6 +552,14 @@ xchk_nlinks_compare_inode(
unsigned int actual_nlink;
int error;
+ /*
+ * Ignore temporary files being used to stage repairs, since we assume
+ * they're correct for non-directories, and the directory repair code
+ * doesn't bump the link counts for the children.
+ */
+ if (xrep_is_tempfile(ip))
+ return 0;
+
xfs_ilock(ip, XFS_ILOCK_SHARED);
mutex_lock(&xnc->lock);
diff --git a/fs/xfs/scrub/nlinks_repair.c b/fs/xfs/scrub/nlinks_repair.c
index 58cacb8e94c1b..23eb08c4b5ad5 100644
--- a/fs/xfs/scrub/nlinks_repair.c
+++ b/fs/xfs/scrub/nlinks_repair.c
@@ -26,6 +26,7 @@
#include "scrub/iscan.h"
#include "scrub/nlinks.h"
#include "scrub/trace.h"
+#include "scrub/tempfile.h"
/*
* Live Inode Link Count Repair
@@ -68,6 +69,14 @@ xrep_nlinks_repair_inode(
bool dirty = false;
int error;
+ /*
+ * Ignore temporary files being used to stage repairs, since we assume
+ * they're correct for non-directories, and the directory repair code
+ * doesn't bump the link counts for the children.
+ */
+ if (xrep_is_tempfile(ip))
+ return 0;
+
xchk_ilock(sc, XFS_IOLOCK_EXCL);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &sc->tp);
diff --git a/fs/xfs/scrub/parent.c b/fs/xfs/scrub/parent.c
index 5da10ed1fe8ce..050a8e8914f6e 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/tempfile.h"
/* Set us up to scrub parents. */
int
@@ -143,7 +144,8 @@ xchk_parent_validate(
}
if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, 0, &error))
return error;
- if (dp == sc->ip || dp == sc->tempip || !S_ISDIR(VFS_I(dp)->i_mode)) {
+ if (dp == sc->ip || xrep_is_tempfile(dp) ||
+ !S_ISDIR(VFS_I(dp)->i_mode)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
goto out_rele;
}
diff --git a/fs/xfs/scrub/readdir.c b/fs/xfs/scrub/readdir.c
index 3edb0bedc0cc0..de8453c435ec6 100644
--- a/fs/xfs/scrub/readdir.c
+++ b/fs/xfs/scrub/readdir.c
@@ -333,6 +333,13 @@ xchk_dir_lookup(
if (xfs_is_shutdown(dp->i_mount))
return -EIO;
+ /*
+ * A temporary directory's block headers are written with the owner
+ * set to sc->ip, so we must switch the owner here for the lookup.
+ */
+ if (dp == sc->tempip)
+ args.owner = sc->ip->i_ino;
+
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index eabc085ff00f8..9cf0014ecd3e0 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -35,6 +35,7 @@
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_attr.h"
+#include "xfs_dir2.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index 9cbfd8da5620b..4e25aa95753a9 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -91,6 +91,7 @@ int xrep_metadata_inode_forks(struct xfs_scrub *sc);
int xrep_setup_ag_rmapbt(struct xfs_scrub *sc);
int xrep_setup_ag_refcountbt(struct xfs_scrub *sc);
int xrep_setup_xattr(struct xfs_scrub *sc);
+int xrep_setup_directory(struct xfs_scrub *sc);
/* Repair setup functions */
int xrep_setup_ag_allocbt(struct xfs_scrub *sc);
@@ -125,6 +126,7 @@ int xrep_bmap_cow(struct xfs_scrub *sc);
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);
#ifdef CONFIG_XFS_RT
int xrep_rtbitmap(struct xfs_scrub *sc);
@@ -195,6 +197,7 @@ xrep_setup_nothing(
#define xrep_setup_ag_rmapbt xrep_setup_nothing
#define xrep_setup_ag_refcountbt xrep_setup_nothing
#define xrep_setup_xattr xrep_setup_nothing
+#define xrep_setup_directory xrep_setup_nothing
#define xrep_setup_inode(sc, imap) ((void)0)
@@ -221,6 +224,7 @@ xrep_setup_nothing(
#define xrep_fscounters xrep_notsupported
#define xrep_rtsummary xrep_notsupported
#define xrep_xattr xrep_notsupported
+#define xrep_directory xrep_notsupported
#endif /* CONFIG_XFS_ONLINE_REPAIR */
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 547189a14b6bf..8e9e2bf121c2b 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -325,7 +325,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
.type = ST_INODE,
.setup = xchk_setup_directory,
.scrub = xchk_directory,
- .repair = xrep_notsupported,
+ .repair = xrep_directory,
},
[XFS_SCRUB_TYPE_XATTR] = { /* extended attributes */
.type = ST_INODE,
diff --git a/fs/xfs/scrub/tempfile.c b/fs/xfs/scrub/tempfile.c
index 37f74486abde3..dd031e6542aca 100644
--- a/fs/xfs/scrub/tempfile.c
+++ b/fs/xfs/scrub/tempfile.c
@@ -844,3 +844,16 @@ xrep_tempfile_copyout_local(
ilog_flags |= xfs_ilog_fdata(whichfork);
xfs_trans_log_inode(sc->tp, sc->ip, ilog_flags);
}
+
+/* Decide if a given XFS inode is a temporary file for a repair. */
+bool
+xrep_is_tempfile(
+ const struct xfs_inode *ip)
+{
+ const struct inode *inode = &ip->i_vnode;
+
+ if (IS_PRIVATE(inode) && !(inode->i_opflags & IOP_XATTR))
+ return true;
+
+ return false;
+}
diff --git a/fs/xfs/scrub/tempfile.h b/fs/xfs/scrub/tempfile.h
index d57e4f145a7c8..e51399f595fe9 100644
--- a/fs/xfs/scrub/tempfile.h
+++ b/fs/xfs/scrub/tempfile.h
@@ -35,11 +35,13 @@ int xrep_tempfile_set_isize(struct xfs_scrub *sc, unsigned long long isize);
int xrep_tempfile_roll_trans(struct xfs_scrub *sc);
void xrep_tempfile_copyout_local(struct xfs_scrub *sc, int whichfork);
+bool xrep_is_tempfile(const struct xfs_inode *ip);
#else
static inline void xrep_tempfile_iolock_both(struct xfs_scrub *sc)
{
xchk_ilock(sc, XFS_IOLOCK_EXCL);
}
+# define xrep_is_tempfile(ip) (false)
# define xrep_tempfile_rele(sc)
#endif /* CONFIG_XFS_ONLINE_REPAIR */
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 06d31b9dd0f47..db0caef0748ab 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -2494,6 +2494,118 @@ DEFINE_EVENT(xrep_xattr_class, name, \
DEFINE_XREP_XATTR_EVENT(xrep_xattr_rebuild_tree);
DEFINE_XREP_XATTR_EVENT(xrep_xattr_reset_fork);
+TRACE_EVENT(xrep_dir_recover_dirblock,
+ TP_PROTO(struct xfs_inode *dp, xfs_dablk_t dabno, uint32_t magic,
+ uint32_t magic_guess),
+ TP_ARGS(dp, dabno, magic, magic_guess),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, dir_ino)
+ __field(xfs_dablk_t, dabno)
+ __field(uint32_t, magic)
+ __field(uint32_t, magic_guess)
+ ),
+ TP_fast_assign(
+ __entry->dev = dp->i_mount->m_super->s_dev;
+ __entry->dir_ino = dp->i_ino;
+ __entry->dabno = dabno;
+ __entry->magic = magic;
+ __entry->magic_guess = magic_guess;
+ ),
+ TP_printk("dev %d:%d dir 0x%llx dablk 0x%x magic 0x%x magic_guess 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->dir_ino,
+ __entry->dabno,
+ __entry->magic,
+ __entry->magic_guess)
+);
+
+DECLARE_EVENT_CLASS(xrep_dir_class,
+ TP_PROTO(struct xfs_inode *dp, xfs_ino_t parent_ino),
+ TP_ARGS(dp, parent_ino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, dir_ino)
+ __field(xfs_ino_t, parent_ino)
+ ),
+ TP_fast_assign(
+ __entry->dev = dp->i_mount->m_super->s_dev;
+ __entry->dir_ino = dp->i_ino;
+ __entry->parent_ino = parent_ino;
+ ),
+ TP_printk("dev %d:%d dir 0x%llx parent 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->dir_ino,
+ __entry->parent_ino)
+)
+#define DEFINE_XREP_DIR_EVENT(name) \
+DEFINE_EVENT(xrep_dir_class, name, \
+ TP_PROTO(struct xfs_inode *dp, xfs_ino_t parent_ino), \
+ TP_ARGS(dp, parent_ino))
+DEFINE_XREP_DIR_EVENT(xrep_dir_rebuild_tree);
+DEFINE_XREP_DIR_EVENT(xrep_dir_reset_fork);
+
+DECLARE_EVENT_CLASS(xrep_dirent_class,
+ TP_PROTO(struct xfs_inode *dp, const struct xfs_name *name,
+ xfs_ino_t ino),
+ TP_ARGS(dp, name, ino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, dir_ino)
+ __field(unsigned int, namelen)
+ __dynamic_array(char, name, name->len)
+ __field(xfs_ino_t, ino)
+ __field(uint8_t, ftype)
+ ),
+ TP_fast_assign(
+ __entry->dev = dp->i_mount->m_super->s_dev;
+ __entry->dir_ino = dp->i_ino;
+ __entry->namelen = name->len;
+ memcpy(__get_str(name), name->name, name->len);
+ __entry->ino = ino;
+ __entry->ftype = name->type;
+ ),
+ TP_printk("dev %d:%d dir 0x%llx ftype %s name '%.*s' ino 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->dir_ino,
+ __print_symbolic(__entry->ftype, XFS_DIR3_FTYPE_STR),
+ __entry->namelen,
+ __get_str(name),
+ __entry->ino)
+)
+#define DEFINE_XREP_DIRENT_EVENT(name) \
+DEFINE_EVENT(xrep_dirent_class, name, \
+ TP_PROTO(struct xfs_inode *dp, const struct xfs_name *name, \
+ xfs_ino_t ino), \
+ TP_ARGS(dp, name, ino))
+DEFINE_XREP_DIRENT_EVENT(xrep_dir_salvage_entry);
+DEFINE_XREP_DIRENT_EVENT(xrep_dir_stash_createname);
+DEFINE_XREP_DIRENT_EVENT(xrep_dir_replay_createname);
+
+DECLARE_EVENT_CLASS(xrep_parent_salvage_class,
+ TP_PROTO(struct xfs_inode *dp, xfs_ino_t ino),
+ TP_ARGS(dp, ino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, dir_ino)
+ __field(xfs_ino_t, ino)
+ ),
+ TP_fast_assign(
+ __entry->dev = dp->i_mount->m_super->s_dev;
+ __entry->dir_ino = dp->i_ino;
+ __entry->ino = ino;
+ ),
+ TP_printk("dev %d:%d dir 0x%llx parent 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->dir_ino,
+ __entry->ino)
+)
+#define DEFINE_XREP_PARENT_SALVAGE_EVENT(name) \
+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_EVENT(xrep_dir_salvaged_parent);
+
#endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
#endif /* _TRACE_XFS_SCRUB_TRACE_H */
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index e6588790e39ae..4ec8a1dd7cf9a 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -16,6 +16,7 @@
#include "xfs_inode.h"
#include "xfs_dir2.h"
#include "xfs_attr.h"
+#include "xfs_bit.h"
#include "xfs_trans_space.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
@@ -1562,6 +1563,51 @@ xfs_release(
return error;
}
+/*
+ * Mark all the buffers attached to this directory stale. In theory we should
+ * never be freeing a directory with any blocks at all, but this covers the
+ * case where we've recovered a directory swap with a "temporary" directory
+ * created by online repair and now need to dump it.
+ */
+STATIC void
+xfs_inactive_dir(
+ struct xfs_inode *dp)
+{
+ struct xfs_iext_cursor icur;
+ struct xfs_bmbt_irec got;
+ struct xfs_mount *mp = dp->i_mount;
+ struct xfs_da_geometry *geo = mp->m_dir_geo;
+ struct xfs_ifork *ifp = xfs_ifork_ptr(dp, XFS_DATA_FORK);
+ xfs_fileoff_t off;
+
+ /*
+ * Invalidate each directory block. All directory blocks are of
+ * fsbcount length and alignment, so we only need to walk those same
+ * offsets. We hold the only reference to this inode, so we must wait
+ * for the buffer locks.
+ */
+ for_each_xfs_iext(ifp, &icur, &got) {
+ for (off = round_up(got.br_startoff, geo->fsbcount);
+ off < got.br_startoff + got.br_blockcount;
+ off += geo->fsbcount) {
+ struct xfs_buf *bp = NULL;
+ xfs_fsblock_t fsbno;
+ int error;
+
+ fsbno = (off - got.br_startoff) + got.br_startblock;
+ error = xfs_buf_incore(mp->m_ddev_targp,
+ XFS_FSB_TO_DADDR(mp, fsbno),
+ XFS_FSB_TO_BB(mp, geo->fsbcount),
+ XBF_LIVESCAN, &bp);
+ if (error)
+ continue;
+
+ xfs_buf_stale(bp);
+ xfs_buf_relse(bp);
+ }
+ }
+}
+
/*
* xfs_inactive_truncate
*
@@ -1872,6 +1918,11 @@ xfs_inactive(
goto out;
}
+ if (S_ISDIR(VFS_I(ip)->i_mode) && ip->i_df.if_nextents > 0) {
+ xfs_inactive_dir(ip);
+ truncate = 1;
+ }
+
if (S_ISLNK(VFS_I(ip)->i_mode))
error = xfs_inactive_symlink(ip);
else if (truncate)
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 2/4] xfs: scan the filesystem to repair a directory dotdot entry
2024-02-27 2:18 [PATCHSET v29.4 09/13] xfs: online repair of directories Darrick J. Wong
2024-02-27 2:31 ` [PATCH 1/4] " Darrick J. Wong
@ 2024-02-27 2:31 ` Darrick J. Wong
2024-02-28 17:17 ` Christoph Hellwig
2024-02-27 2:31 ` [PATCH 3/4] xfs: online repair of parent pointers Darrick J. Wong
2024-02-27 2:31 ` [PATCH 4/4] xfs: ask the dentry cache if it knows the parent of a directory Darrick J. Wong
3 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-02-27 2:31 UTC (permalink / raw)
To: djwong; +Cc: linux-xfs, hch
From: Darrick J. Wong <djwong@kernel.org>
Teach the online directory repair code to scan the filesystem so that we
can set the dotdot entry when we're rebuilding a directory. This
involves dropping ILOCK on the directory that we're repairing, which
means that the VFS can sneak in and tell us to update dotdot at any
time. Deal with these races by using a dirent hook to absorb dotdot
updates, and be careful not to check the scan results until after we've
retaken the ILOCK.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/Makefile | 1
fs/xfs/scrub/dir_repair.c | 70 +++++---
fs/xfs/scrub/findparent.c | 412 +++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/findparent.h | 49 +++++
fs/xfs/scrub/iscan.c | 18 ++
fs/xfs/scrub/iscan.h | 1
fs/xfs/scrub/trace.h | 1
7 files changed, 528 insertions(+), 24 deletions(-)
create mode 100644 fs/xfs/scrub/findparent.c
create mode 100644 fs/xfs/scrub/findparent.h
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index cdb2ee814300d..59e341083e10e 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -200,6 +200,7 @@ xfs-y += $(addprefix scrub/, \
bmap_repair.o \
cow_repair.o \
dir_repair.o \
+ findparent.o \
fscounters_repair.o \
ialloc_repair.o \
inode_repair.o \
diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c
index 959b921752e84..e6979ed49408d 100644
--- a/fs/xfs/scrub/dir_repair.c
+++ b/fs/xfs/scrub/dir_repair.c
@@ -38,8 +38,10 @@
#include "scrub/xfile.h"
#include "scrub/xfarray.h"
#include "scrub/xfblob.h"
+#include "scrub/iscan.h"
#include "scrub/readdir.h"
#include "scrub/reap.h"
+#include "scrub/findparent.h"
/*
* Directory Repair
@@ -108,10 +110,10 @@ struct xrep_dir {
struct xfs_da_args args;
/*
- * This is the parent that we're going to set on the reconstructed
- * directory.
+ * Information used to scan the filesystem to find the inumber of the
+ * dotdot entry for this directory.
*/
- xfs_ino_t parent_ino;
+ struct xrep_parent_scan_info pscan;
/* How many subdirectories did we find? */
uint64_t subdirs;
@@ -130,6 +132,7 @@ xrep_dir_teardown(
{
struct xrep_dir *rd = sc->buf;
+ xrep_findparent_scan_teardown(&rd->pscan);
xfblob_destroy(rd->dir_names);
xfarray_destroy(rd->dir_entries);
}
@@ -142,6 +145,8 @@ xrep_setup_directory(
struct xrep_dir *rd;
int error;
+ xchk_fsgates_enable(sc, XCHK_FSGATES_DIRENTS);
+
error = xrep_tempfile_create(sc, S_IFDIR);
if (error)
return error;
@@ -177,8 +182,8 @@ xrep_dir_self_parent(
}
/*
- * Look up the dotdot entry. Returns NULLFSINO if we don't know what to do.
- * The next patch will check this more carefully.
+ * 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_lookup_parent(
@@ -194,37 +199,39 @@ xrep_dir_lookup_parent(
if (!xfs_verify_dir_ino(sc->mp, ino))
return NULLFSINO;
+ error = xrep_findparent_confirm(sc, &ino);
+ if (error)
+ return NULLFSINO;
+
return ino;
}
-/*
- * 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)
{
xfs_ino_t ino;
- ino = xrep_dir_self_parent(rd);
+ ino = xrep_findparent_self_reference(rd->sc);
if (ino != NULLFSINO) {
- rd->parent_ino = ino;
+ xrep_findparent_scan_finish_early(&rd->pscan, ino);
return 0;
}
ino = xrep_dir_lookup_parent(rd);
if (ino != NULLFSINO) {
- rd->parent_ino = ino;
+ xrep_findparent_scan_finish_early(&rd->pscan, ino);
return 0;
}
- /* NOTE: A future patch will deal with moving orphans. */
- return -EFSCORRUPTED;
+ /*
+ * 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.
+ */
+ return xrep_findparent_scan(&rd->pscan);
}
/*
@@ -933,6 +940,10 @@ xrep_dir_salvage_entries(
* the directory until we're ready for the exchange operation. Reads
* will return -EIO without shutting down the fs, so we're ok with
* that.
+ *
+ * The VFS can change dotdot on us, but the findparent scan will keep
+ * our incore parent inode up to date. See the note on locking issues
+ * for more details.
*/
error = xrep_trans_commit(sc);
if (error)
@@ -1156,6 +1167,14 @@ xrep_dir_swap(
if (rd->subdirs + 2 > XFS_MAXLINK)
return -EFSCORRUPTED;
+ /*
+ * If we never found the parent for this directory, we can't fix this
+ * directory.
+ */
+ ASSERT(sc->ilock_flags & XFS_ILOCK_EXCL);
+ if (rd->pscan.parent_ino == NULLFSINO)
+ return -EFSCORRUPTED;
+
/*
* Reset the temporary directory's '..' entry to point to the parent
* that we found. The temporary directory was created with the root
@@ -1165,9 +1184,9 @@ xrep_dir_swap(
* It's also possible that this replacement could also expand a sf
* tempdir into block format.
*/
- if (rd->parent_ino != sc->mp->m_rootip->i_ino) {
+ if (rd->pscan.parent_ino != sc->mp->m_rootip->i_ino) {
error = xrep_dir_replace(rd, rd->sc->tempip, &xfs_name_dotdot,
- rd->parent_ino, rd->tx.req.resblks);
+ rd->pscan.parent_ino, rd->tx.req.resblks);
if (error)
return error;
}
@@ -1226,7 +1245,7 @@ xrep_dir_rebuild_tree(
struct xfs_scrub *sc = rd->sc;
int error;
- trace_xrep_dir_rebuild_tree(sc->ip, rd->parent_ino);
+ trace_xrep_dir_rebuild_tree(sc->ip, rd->pscan.parent_ino);
/*
* Take the IOLOCK on the temporary file so that we can run dir
@@ -1283,8 +1302,6 @@ xrep_dir_setup_scan(
char *descr;
int error;
- rd->parent_ino = NULLFSINO;
-
/* Set up some staging memory for salvaging dirents. */
descr = xchk_xfile_ino_descr(sc, "directory entries");
error = xfarray_create(descr, 0, sizeof(struct xrep_dirent),
@@ -1299,8 +1316,15 @@ xrep_dir_setup_scan(
if (error)
goto out_xfarray;
+ error = xrep_findparent_scan_start(sc, &rd->pscan);
+ if (error)
+ goto out_xfblob;
+
return 0;
+out_xfblob:
+ xfblob_destroy(rd->dir_names);
+ rd->dir_names = NULL;
out_xfarray:
xfarray_destroy(rd->dir_entries);
rd->dir_entries = NULL;
diff --git a/fs/xfs/scrub/findparent.c b/fs/xfs/scrub/findparent.c
new file mode 100644
index 0000000000000..7b3ec8d7d6cc9
--- /dev/null
+++ b/fs/xfs/scrub/findparent.c
@@ -0,0 +1,412 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 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_exchmaps.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/findparent.h"
+#include "scrub/readdir.h"
+#include "scrub/tempfile.h"
+
+/*
+ * Finding the Parent of a Directory
+ * =================================
+ *
+ * Directories have parent pointers, in the sense that each directory contains
+ * a dotdot entry that points to the single allowed parent. The brute force
+ * way to find the parent of a given directory is to scan every directory in
+ * the filesystem looking for a child dirent that references this directory.
+ *
+ * This module wraps the process of scanning the directory tree. It requires
+ * that @sc->ip is the directory whose parent we want to find, and that the
+ * caller hold only the IOLOCK on that directory. The scan itself needs to
+ * take the ILOCK of each directory visited.
+ *
+ * Because we cannot hold @sc->ip's ILOCK during a scan of the whole fs, it is
+ * necessary to use dirent hook to update the parent scan results. Callers
+ * must not read the scan results without re-taking @sc->ip's ILOCK.
+ *
+ * There are a few shortcuts that we can take to avoid scanning the entire
+ * filesystem, such as noticing directory tree roots.
+ */
+
+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;
+
+ /* Optional scan information for a xrep_findparent_scan call. */
+ struct xrep_parent_scan_info *parent_scan;
+
+ /*
+ * 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;
+
+ if (fpi->parent_scan)
+ xrep_findparent_scan_found(fpi->parent_scan, fpi->dp->i_ino);
+
+ 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;
+
+ /*
+ * 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);
+
+ /*
+ * 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;
+ }
+
+ /*
+ * We cannot complete our parent pointer scan if a directory looks as
+ * though it has been zapped by the inode record repair code.
+ */
+ if (xchk_dir_looks_zapped(dp)) {
+ error = -EBUSY;
+ goto out_unlock;
+ }
+
+ error = xchk_dir_walk(sc, dp, xrep_findparent_dirent, fpi);
+ if (error)
+ goto out_unlock;
+
+out_unlock:
+ xfs_iunlock(dp, lock_mode);
+ return error;
+}
+
+/*
+ * Update this directory's dotdot pointer based on ongoing dirent updates.
+ */
+STATIC int
+xrep_findparent_live_update(
+ struct notifier_block *nb,
+ unsigned long action,
+ void *data)
+{
+ struct xfs_dir_update_params *p = data;
+ struct xrep_parent_scan_info *pscan;
+ struct xfs_scrub *sc;
+
+ pscan = container_of(nb, struct xrep_parent_scan_info,
+ dhook.dirent_hook.nb);
+ sc = pscan->sc;
+
+ /*
+ * If @p->ip is the subdirectory that we're interested in and we've
+ * already scanned @p->dp, update the dotdot target inumber to the
+ * parent inode.
+ */
+ if (p->ip->i_ino == sc->ip->i_ino &&
+ xchk_iscan_want_live_update(&pscan->iscan, p->dp->i_ino)) {
+ if (p->delta > 0) {
+ xrep_findparent_scan_found(pscan, p->dp->i_ino);
+ } else {
+ xrep_findparent_scan_found(pscan, NULLFSINO);
+ }
+ }
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * Set up a scan to find the parent of a directory. The provided dirent hook
+ * will be called when there is a dotdot update for the inode being repaired.
+ */
+int
+xrep_findparent_scan_start(
+ struct xfs_scrub *sc,
+ struct xrep_parent_scan_info *pscan)
+{
+ int error;
+
+ if (!(sc->flags & XCHK_FSGATES_DIRENTS)) {
+ ASSERT(sc->flags & XCHK_FSGATES_DIRENTS);
+ return -EINVAL;
+ }
+
+ pscan->sc = sc;
+ pscan->parent_ino = NULLFSINO;
+
+ mutex_init(&pscan->lock);
+
+ xchk_iscan_start(sc, 30000, 100, &pscan->iscan);
+
+ /*
+ * Hook into the dirent update code. The hook only operates on inodes
+ * that were already scanned, and the scanner thread takes each inode's
+ * ILOCK, which means that any in-progress inode updates will finish
+ * before we can scan the inode.
+ */
+ xfs_dir_hook_setup(&pscan->dhook, xrep_findparent_live_update);
+ error = xfs_dir_hook_add(sc->mp, &pscan->dhook);
+ if (error)
+ goto out_iscan;
+
+ return 0;
+out_iscan:
+ xchk_iscan_teardown(&pscan->iscan);
+ mutex_destroy(&pscan->lock);
+ 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. Callers must
+ * not hold a dirty transaction or any lock that would interfere with taking
+ * an ILOCK.
+ *
+ * Returns 0 with @pscan->parent_ino set to the parent that we found.
+ * Returns 0 with @pscan->parent_ino set to NULLFSINO if we found no parents.
+ * Returns the usual negative errno if something else happened.
+ */
+int
+xrep_findparent_scan(
+ struct xrep_parent_scan_info *pscan)
+{
+ struct xrep_findparent_info fpi = {
+ .sc = pscan->sc,
+ .found_parent = NULLFSINO,
+ .parent_scan = pscan,
+ };
+ struct xfs_scrub *sc = pscan->sc;
+ int ret;
+
+ ASSERT(S_ISDIR(VFS_IC(sc->ip)->i_mode));
+
+ while ((ret = xchk_iscan_iter(&pscan->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(&pscan->iscan, fpi.dp);
+ xchk_irele(sc, fpi.dp);
+ if (ret)
+ break;
+
+ if (xchk_should_terminate(sc, &ret))
+ break;
+ }
+ xchk_iscan_iter_finish(&pscan->iscan);
+
+ return ret;
+}
+
+/* Tear down a parent scan. */
+void
+xrep_findparent_scan_teardown(
+ struct xrep_parent_scan_info *pscan)
+{
+ xfs_dir_hook_del(pscan->sc->mp, &pscan->dhook);
+ xchk_iscan_teardown(&pscan->iscan);
+ mutex_destroy(&pscan->lock);
+}
+
+/* Finish a parent scan early. */
+void
+xrep_findparent_scan_finish_early(
+ struct xrep_parent_scan_info *pscan,
+ xfs_ino_t ino)
+{
+ xrep_findparent_scan_found(pscan, ino);
+ xchk_iscan_finish_early(&pscan->iscan);
+}
+
+/*
+ * 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 @parent_ino set to NULLFSINO if the parent was not valid.
+ * Returns the usual negative errno if something else happened.
+ */
+int
+xrep_findparent_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;
+}
+
+/*
+ * 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_findparent_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;
+}
diff --git a/fs/xfs/scrub/findparent.h b/fs/xfs/scrub/findparent.h
new file mode 100644
index 0000000000000..d946bc81f34e6
--- /dev/null
+++ b/fs/xfs/scrub/findparent.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2020-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_FINDPARENT_H__
+#define __XFS_SCRUB_FINDPARENT_H__
+
+struct xrep_parent_scan_info {
+ struct xfs_scrub *sc;
+
+ /* Inode scan cursor. */
+ struct xchk_iscan iscan;
+
+ /* Hook to capture directory entry updates. */
+ struct xfs_dir_hook dhook;
+
+ /* Lock protecting parent_ino. */
+ struct mutex lock;
+
+ /* Parent inode that we've found. */
+ xfs_ino_t parent_ino;
+
+ bool lookup_parent;
+};
+
+int xrep_findparent_scan_start(struct xfs_scrub *sc,
+ struct xrep_parent_scan_info *pscan);
+int xrep_findparent_scan(struct xrep_parent_scan_info *pscan);
+void xrep_findparent_scan_teardown(struct xrep_parent_scan_info *pscan);
+
+static inline void
+xrep_findparent_scan_found(
+ struct xrep_parent_scan_info *pscan,
+ xfs_ino_t ino)
+{
+ mutex_lock(&pscan->lock);
+ pscan->parent_ino = ino;
+ mutex_unlock(&pscan->lock);
+}
+
+void xrep_findparent_scan_finish_early(struct xrep_parent_scan_info *pscan,
+ xfs_ino_t ino);
+
+int xrep_findparent_confirm(struct xfs_scrub *sc, xfs_ino_t *parent_ino);
+
+xfs_ino_t xrep_findparent_self_reference(struct xfs_scrub *sc);
+
+#endif /* __XFS_SCRUB_FINDPARENT_H__ */
diff --git a/fs/xfs/scrub/iscan.c b/fs/xfs/scrub/iscan.c
index ec3478bc505ef..71a04f3bd91c1 100644
--- a/fs/xfs/scrub/iscan.c
+++ b/fs/xfs/scrub/iscan.c
@@ -243,6 +243,17 @@ xchk_iscan_finish(
mutex_unlock(&iscan->lock);
}
+/* Mark an inode scan finished before we actually scan anything. */
+void
+xchk_iscan_finish_early(
+ struct xchk_iscan *iscan)
+{
+ ASSERT(iscan->cursor_ino == iscan->scan_start_ino);
+ ASSERT(iscan->__visited_ino == iscan->scan_start_ino);
+
+ xchk_iscan_finish(iscan);
+}
+
/*
* Advance ino to the next inode that the inobt thinks is allocated, being
* careful to jump to the next AG if we've reached the right end of this AG's
@@ -402,8 +413,13 @@ 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.
+ * If we have a non-empty transaction, we must not block on
+ * inodegc, which allocates its own transactions.
*/
- xfs_inodegc_flush(mp);
+ if (sc->tp && !(sc->tp->t_flags & XFS_TRANS_NO_WRITECOUNT))
+ xfs_inodegc_push(mp);
+ else
+ xfs_inodegc_flush(mp);
return xchk_iscan_iget_retry(iscan, true);
}
diff --git a/fs/xfs/scrub/iscan.h b/fs/xfs/scrub/iscan.h
index 71f657552dfac..4c442fce2d8f5 100644
--- a/fs/xfs/scrub/iscan.h
+++ b/fs/xfs/scrub/iscan.h
@@ -73,6 +73,7 @@ xchk_iscan_abort(struct xchk_iscan *iscan)
void xchk_iscan_start(struct xfs_scrub *sc, unsigned int iget_timeout,
unsigned int iget_retry_delay, struct xchk_iscan *iscan);
+void xchk_iscan_finish_early(struct xchk_iscan *iscan);
void xchk_iscan_teardown(struct xchk_iscan *iscan);
int xchk_iscan_iter(struct xchk_iscan *iscan, struct xfs_inode **ipp);
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index db0caef0748ab..8a254180de4f9 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -2605,6 +2605,7 @@ 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_EVENT(xrep_dir_salvaged_parent);
+DEFINE_XREP_PARENT_SALVAGE_EVENT(xrep_findparent_dirent);
#endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
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