v4.19.13 snapshot.
diff --git a/fs/xfs/scrub/attr.c b/fs/xfs/scrub/attr.c
new file mode 100644
index 0000000..81d5e90
--- /dev/null
+++ b/fs/xfs/scrub/attr.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#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_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/dabtree.h"
+#include "scrub/trace.h"
+
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+/* Set us up to scrub an inode's extended attributes. */
+int
+xchk_setup_xattr(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip)
+{
+ size_t sz;
+
+ /*
+ * Allocate the buffer without the inode lock held. We need enough
+ * space to read every xattr value in the file or enough space to
+ * hold three copies of the xattr free space bitmap. (Not both at
+ * the same time.)
+ */
+ sz = max_t(size_t, XATTR_SIZE_MAX, 3 * sizeof(long) *
+ BITS_TO_LONGS(sc->mp->m_attr_geo->blksize));
+ sc->buf = kmem_zalloc_large(sz, KM_SLEEP);
+ if (!sc->buf)
+ return -ENOMEM;
+
+ return xchk_setup_inode_contents(sc, ip, 0);
+}
+
+/* Extended Attributes */
+
+struct xchk_xattr {
+ struct xfs_attr_list_context context;
+ struct xfs_scrub *sc;
+};
+
+/*
+ * Check that an extended attribute key can be looked up by hash.
+ *
+ * We use the XFS attribute list iterator (i.e. xfs_attr_list_int_ilocked)
+ * to call this function for every attribute key in an inode. Once
+ * we're here, we load the attribute value to see if any errors happen,
+ * or if we get more or less data than we expected.
+ */
+static void
+xchk_xattr_listent(
+ struct xfs_attr_list_context *context,
+ int flags,
+ unsigned char *name,
+ int namelen,
+ int valuelen)
+{
+ struct xchk_xattr *sx;
+ struct xfs_da_args args = { NULL };
+ int error = 0;
+
+ sx = container_of(context, struct xchk_xattr, context);
+
+ if (flags & XFS_ATTR_INCOMPLETE) {
+ /* Incomplete attr key, just mark the inode for preening. */
+ xchk_ino_set_preen(sx->sc, context->dp->i_ino);
+ return;
+ }
+
+ args.flags = ATTR_KERNOTIME;
+ if (flags & XFS_ATTR_ROOT)
+ args.flags |= ATTR_ROOT;
+ else if (flags & XFS_ATTR_SECURE)
+ args.flags |= ATTR_SECURE;
+ args.geo = context->dp->i_mount->m_attr_geo;
+ args.whichfork = XFS_ATTR_FORK;
+ args.dp = context->dp;
+ args.name = name;
+ args.namelen = namelen;
+ args.hashval = xfs_da_hashname(args.name, args.namelen);
+ args.trans = context->tp;
+ args.value = sx->sc->buf;
+ args.valuelen = XATTR_SIZE_MAX;
+
+ error = xfs_attr_get_ilocked(context->dp, &args);
+ if (error == -EEXIST)
+ error = 0;
+ if (!xchk_fblock_process_error(sx->sc, XFS_ATTR_FORK, args.blkno,
+ &error))
+ goto fail_xref;
+ if (args.valuelen != valuelen)
+ xchk_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK,
+ args.blkno);
+fail_xref:
+ if (sx->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ context->seen_enough = 1;
+ return;
+}
+
+/*
+ * Mark a range [start, start+len) in this map. Returns true if the
+ * region was free, and false if there's a conflict or a problem.
+ *
+ * Within a char, the lowest bit of the char represents the byte with
+ * the smallest address
+ */
+STATIC bool
+xchk_xattr_set_map(
+ struct xfs_scrub *sc,
+ unsigned long *map,
+ unsigned int start,
+ unsigned int len)
+{
+ unsigned int mapsize = sc->mp->m_attr_geo->blksize;
+ bool ret = true;
+
+ if (start >= mapsize)
+ return false;
+ if (start + len > mapsize) {
+ len = mapsize - start;
+ ret = false;
+ }
+
+ if (find_next_bit(map, mapsize, start) < start + len)
+ ret = false;
+ bitmap_set(map, start, len);
+
+ return ret;
+}
+
+/*
+ * Check the leaf freemap from the usage bitmap. Returns false if the
+ * attr freemap has problems or points to used space.
+ */
+STATIC bool
+xchk_xattr_check_freemap(
+ struct xfs_scrub *sc,
+ unsigned long *map,
+ struct xfs_attr3_icleaf_hdr *leafhdr)
+{
+ unsigned long *freemap;
+ unsigned long *dstmap;
+ unsigned int mapsize = sc->mp->m_attr_geo->blksize;
+ int i;
+
+ /* Construct bitmap of freemap contents. */
+ freemap = (unsigned long *)sc->buf + BITS_TO_LONGS(mapsize);
+ bitmap_zero(freemap, mapsize);
+ for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
+ if (!xchk_xattr_set_map(sc, freemap,
+ leafhdr->freemap[i].base,
+ leafhdr->freemap[i].size))
+ return false;
+ }
+
+ /* Look for bits that are set in freemap and are marked in use. */
+ dstmap = freemap + BITS_TO_LONGS(mapsize);
+ return bitmap_and(dstmap, freemap, map, mapsize) == 0;
+}
+
+/*
+ * Check this leaf entry's relations to everything else.
+ * Returns the number of bytes used for the name/value data.
+ */
+STATIC void
+xchk_xattr_entry(
+ struct xchk_da_btree *ds,
+ int level,
+ char *buf_end,
+ struct xfs_attr_leafblock *leaf,
+ struct xfs_attr3_icleaf_hdr *leafhdr,
+ unsigned long *usedmap,
+ struct xfs_attr_leaf_entry *ent,
+ int idx,
+ unsigned int *usedbytes,
+ __u32 *last_hashval)
+{
+ struct xfs_mount *mp = ds->state->mp;
+ char *name_end;
+ struct xfs_attr_leaf_name_local *lentry;
+ struct xfs_attr_leaf_name_remote *rentry;
+ unsigned int nameidx;
+ unsigned int namesize;
+
+ if (ent->pad2 != 0)
+ xchk_da_set_corrupt(ds, level);
+
+ /* Hash values in order? */
+ if (be32_to_cpu(ent->hashval) < *last_hashval)
+ xchk_da_set_corrupt(ds, level);
+ *last_hashval = be32_to_cpu(ent->hashval);
+
+ nameidx = be16_to_cpu(ent->nameidx);
+ if (nameidx < leafhdr->firstused ||
+ nameidx >= mp->m_attr_geo->blksize) {
+ xchk_da_set_corrupt(ds, level);
+ return;
+ }
+
+ /* Check the name information. */
+ if (ent->flags & XFS_ATTR_LOCAL) {
+ lentry = xfs_attr3_leaf_name_local(leaf, idx);
+ namesize = xfs_attr_leaf_entsize_local(lentry->namelen,
+ be16_to_cpu(lentry->valuelen));
+ name_end = (char *)lentry + namesize;
+ if (lentry->namelen == 0)
+ xchk_da_set_corrupt(ds, level);
+ } else {
+ rentry = xfs_attr3_leaf_name_remote(leaf, idx);
+ namesize = xfs_attr_leaf_entsize_remote(rentry->namelen);
+ name_end = (char *)rentry + namesize;
+ if (rentry->namelen == 0 || rentry->valueblk == 0)
+ xchk_da_set_corrupt(ds, level);
+ }
+ if (name_end > buf_end)
+ xchk_da_set_corrupt(ds, level);
+
+ if (!xchk_xattr_set_map(ds->sc, usedmap, nameidx, namesize))
+ xchk_da_set_corrupt(ds, level);
+ if (!(ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+ *usedbytes += namesize;
+}
+
+/* Scrub an attribute leaf. */
+STATIC int
+xchk_xattr_block(
+ struct xchk_da_btree *ds,
+ int level)
+{
+ struct xfs_attr3_icleaf_hdr leafhdr;
+ struct xfs_mount *mp = ds->state->mp;
+ struct xfs_da_state_blk *blk = &ds->state->path.blk[level];
+ struct xfs_buf *bp = blk->bp;
+ xfs_dablk_t *last_checked = ds->private;
+ struct xfs_attr_leafblock *leaf = bp->b_addr;
+ struct xfs_attr_leaf_entry *ent;
+ struct xfs_attr_leaf_entry *entries;
+ unsigned long *usedmap = ds->sc->buf;
+ char *buf_end;
+ size_t off;
+ __u32 last_hashval = 0;
+ unsigned int usedbytes = 0;
+ unsigned int hdrsize;
+ int i;
+
+ if (*last_checked == blk->blkno)
+ return 0;
+ *last_checked = blk->blkno;
+ bitmap_zero(usedmap, mp->m_attr_geo->blksize);
+
+ /* Check all the padding. */
+ if (xfs_sb_version_hascrc(&ds->sc->mp->m_sb)) {
+ struct xfs_attr3_leafblock *leaf = bp->b_addr;
+
+ if (leaf->hdr.pad1 != 0 || leaf->hdr.pad2 != 0 ||
+ leaf->hdr.info.hdr.pad != 0)
+ xchk_da_set_corrupt(ds, level);
+ } else {
+ if (leaf->hdr.pad1 != 0 || leaf->hdr.info.pad != 0)
+ xchk_da_set_corrupt(ds, level);
+ }
+
+ /* Check the leaf header */
+ xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
+ hdrsize = xfs_attr3_leaf_hdr_size(leaf);
+
+ if (leafhdr.usedbytes > mp->m_attr_geo->blksize)
+ xchk_da_set_corrupt(ds, level);
+ if (leafhdr.firstused > mp->m_attr_geo->blksize)
+ xchk_da_set_corrupt(ds, level);
+ if (leafhdr.firstused < hdrsize)
+ xchk_da_set_corrupt(ds, level);
+ if (!xchk_xattr_set_map(ds->sc, usedmap, 0, hdrsize))
+ xchk_da_set_corrupt(ds, level);
+
+ if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ goto out;
+
+ entries = xfs_attr3_leaf_entryp(leaf);
+ if ((char *)&entries[leafhdr.count] > (char *)leaf + leafhdr.firstused)
+ xchk_da_set_corrupt(ds, level);
+
+ buf_end = (char *)bp->b_addr + mp->m_attr_geo->blksize;
+ for (i = 0, ent = entries; i < leafhdr.count; ent++, i++) {
+ /* Mark the leaf entry itself. */
+ off = (char *)ent - (char *)leaf;
+ if (!xchk_xattr_set_map(ds->sc, usedmap, off,
+ sizeof(xfs_attr_leaf_entry_t))) {
+ xchk_da_set_corrupt(ds, level);
+ goto out;
+ }
+
+ /* Check the entry and nameval. */
+ xchk_xattr_entry(ds, level, buf_end, leaf, &leafhdr,
+ usedmap, ent, i, &usedbytes, &last_hashval);
+
+ if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ goto out;
+ }
+
+ if (!xchk_xattr_check_freemap(ds->sc, usedmap, &leafhdr))
+ xchk_da_set_corrupt(ds, level);
+
+ if (leafhdr.usedbytes != usedbytes)
+ xchk_da_set_corrupt(ds, level);
+
+out:
+ return 0;
+}
+
+/* Scrub a attribute btree record. */
+STATIC int
+xchk_xattr_rec(
+ struct xchk_da_btree *ds,
+ int level,
+ void *rec)
+{
+ struct xfs_mount *mp = ds->state->mp;
+ struct xfs_attr_leaf_entry *ent = rec;
+ struct xfs_da_state_blk *blk;
+ struct xfs_attr_leaf_name_local *lentry;
+ struct xfs_attr_leaf_name_remote *rentry;
+ struct xfs_buf *bp;
+ xfs_dahash_t calc_hash;
+ xfs_dahash_t hash;
+ int nameidx;
+ int hdrsize;
+ unsigned int badflags;
+ int error;
+
+ blk = &ds->state->path.blk[level];
+
+ /* Check the whole block, if necessary. */
+ error = xchk_xattr_block(ds, level);
+ if (error)
+ goto out;
+ if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ goto out;
+
+ /* Check the hash of the entry. */
+ error = xchk_da_btree_hash(ds, level, &ent->hashval);
+ if (error)
+ goto out;
+
+ /* Find the attr entry's location. */
+ bp = blk->bp;
+ hdrsize = xfs_attr3_leaf_hdr_size(bp->b_addr);
+ nameidx = be16_to_cpu(ent->nameidx);
+ if (nameidx < hdrsize || nameidx >= mp->m_attr_geo->blksize) {
+ xchk_da_set_corrupt(ds, level);
+ goto out;
+ }
+
+ /* Retrieve the entry and check it. */
+ hash = be32_to_cpu(ent->hashval);
+ badflags = ~(XFS_ATTR_LOCAL | XFS_ATTR_ROOT | XFS_ATTR_SECURE |
+ XFS_ATTR_INCOMPLETE);
+ if ((ent->flags & badflags) != 0)
+ xchk_da_set_corrupt(ds, level);
+ if (ent->flags & XFS_ATTR_LOCAL) {
+ lentry = (struct xfs_attr_leaf_name_local *)
+ (((char *)bp->b_addr) + nameidx);
+ if (lentry->namelen <= 0) {
+ xchk_da_set_corrupt(ds, level);
+ goto out;
+ }
+ calc_hash = xfs_da_hashname(lentry->nameval, lentry->namelen);
+ } else {
+ rentry = (struct xfs_attr_leaf_name_remote *)
+ (((char *)bp->b_addr) + nameidx);
+ if (rentry->namelen <= 0) {
+ xchk_da_set_corrupt(ds, level);
+ goto out;
+ }
+ calc_hash = xfs_da_hashname(rentry->name, rentry->namelen);
+ }
+ if (calc_hash != hash)
+ xchk_da_set_corrupt(ds, level);
+
+out:
+ return error;
+}
+
+/* Scrub the extended attribute metadata. */
+int
+xchk_xattr(
+ struct xfs_scrub *sc)
+{
+ struct xchk_xattr sx;
+ struct attrlist_cursor_kern cursor = { 0 };
+ xfs_dablk_t last_checked = -1U;
+ int error = 0;
+
+ if (!xfs_inode_hasattr(sc->ip))
+ return -ENOENT;
+
+ memset(&sx, 0, sizeof(sx));
+ /* Check attribute tree structure */
+ error = xchk_da_btree(sc, XFS_ATTR_FORK, xchk_xattr_rec,
+ &last_checked);
+ if (error)
+ goto out;
+
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ goto out;
+
+ /* Check that every attr key can also be looked up by hash. */
+ sx.context.dp = sc->ip;
+ sx.context.cursor = &cursor;
+ sx.context.resynch = 1;
+ sx.context.put_listent = xchk_xattr_listent;
+ sx.context.tp = sc->tp;
+ sx.context.flags = ATTR_INCOMPLETE;
+ sx.sc = sc;
+
+ /*
+ * Look up every xattr in this file by name.
+ *
+ * Use the backend implementation of xfs_attr_list to call
+ * xchk_xattr_listent on every attribute key in this inode.
+ * In other words, we use the same iterator/callback mechanism
+ * that listattr uses to scrub extended attributes, though in our
+ * _listent function, we check the value of the attribute.
+ *
+ * The VFS only locks i_rwsem when modifying attrs, so keep all
+ * three locks held because that's the only way to ensure we're
+ * the only thread poking into the da btree. We traverse the da
+ * btree while holding a leaf buffer locked for the xattr name
+ * iteration, which doesn't really follow the usual buffer
+ * locking order.
+ */
+ error = xfs_attr_list_int_ilocked(&sx.context);
+ if (!xchk_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error))
+ goto out;
+out:
+ return error;
+}