diff options
Diffstat (limited to 'fs/xfs/scrub/attr.c')
| -rw-r--r-- | fs/xfs/scrub/attr.c | 683 |
1 files changed, 683 insertions, 0 deletions
diff --git a/fs/xfs/scrub/attr.c b/fs/xfs/scrub/attr.c new file mode 100644 index 000000000000..708334f9b2bd --- /dev/null +++ b/fs/xfs/scrub/attr.c @@ -0,0 +1,683 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2017-2023 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_log_format.h" +#include "xfs_trans.h" +#include "xfs_inode.h" +#include "xfs_da_format.h" +#include "xfs_da_btree.h" +#include "xfs_attr.h" +#include "xfs_attr_leaf.h" +#include "xfs_attr_sf.h" +#include "xfs_parent.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/dabtree.h" +#include "scrub/attr.h" +#include "scrub/listxattr.h" +#include "scrub/repair.h" + +/* Free the buffers linked from the xattr buffer. */ +static void +xchk_xattr_buf_cleanup( + void *priv) +{ + struct xchk_xattr_buf *ab = priv; + + kvfree(ab->freemap); + ab->freemap = NULL; + kvfree(ab->usedmap); + ab->usedmap = NULL; + kvfree(ab->value); + ab->value = NULL; + ab->value_sz = 0; + kvfree(ab->name); + ab->name = NULL; +} + +/* + * Allocate the free space bitmap if we're trying harder; there are leaf blocks + * in the attr fork; or we can't tell if there are leaf blocks. + */ +static inline bool +xchk_xattr_want_freemap( + struct xfs_scrub *sc) +{ + struct xfs_ifork *ifp; + + if (sc->flags & XCHK_TRY_HARDER) + return true; + + if (!sc->ip) + return true; + + ifp = xfs_ifork_ptr(sc->ip, XFS_ATTR_FORK); + if (!ifp) + return false; + + return xfs_ifork_has_extents(ifp); +} + +/* + * Allocate enough memory to hold an attr value and attr block bitmaps, + * reallocating the buffer if necessary. Buffer contents are not preserved + * across a reallocation. + */ +int +xchk_setup_xattr_buf( + struct xfs_scrub *sc, + size_t value_size) +{ + size_t bmp_sz; + struct xchk_xattr_buf *ab = sc->buf; + void *new_val; + + bmp_sz = sizeof(long) * BITS_TO_LONGS(sc->mp->m_attr_geo->blksize); + + if (ab) + goto resize_value; + + ab = kvzalloc(sizeof(struct xchk_xattr_buf), XCHK_GFP_FLAGS); + if (!ab) + return -ENOMEM; + sc->buf = ab; + sc->buf_cleanup = xchk_xattr_buf_cleanup; + + ab->usedmap = kvmalloc(bmp_sz, XCHK_GFP_FLAGS); + if (!ab->usedmap) + return -ENOMEM; + + if (xchk_xattr_want_freemap(sc)) { + ab->freemap = kvmalloc(bmp_sz, XCHK_GFP_FLAGS); + if (!ab->freemap) + return -ENOMEM; + } + + if (xchk_could_repair(sc)) { + ab->name = kvmalloc(XATTR_NAME_MAX + 1, XCHK_GFP_FLAGS); + if (!ab->name) + return -ENOMEM; + } + +resize_value: + if (ab->value_sz >= value_size) + return 0; + + if (ab->value) { + kvfree(ab->value); + ab->value = NULL; + ab->value_sz = 0; + } + + new_val = kvmalloc(value_size, XCHK_GFP_FLAGS); + if (!new_val) + return -ENOMEM; + + ab->value = new_val; + ab->value_sz = value_size; + return 0; +} + +/* Set us up to scrub an inode's extended attributes. */ +int +xchk_setup_xattr( + struct xfs_scrub *sc) +{ + int error; + + if (xchk_could_repair(sc)) { + error = xrep_setup_xattr(sc); + if (error) + return error; + } + + /* + * We failed to get memory while checking attrs, so this time try to + * get all the memory we're ever going to need. Allocate the buffer + * without the inode lock held, which means we can sleep. + */ + if (sc->flags & XCHK_TRY_HARDER) { + error = xchk_setup_xattr_buf(sc, XATTR_SIZE_MAX); + if (error) + return error; + } + + return xchk_setup_inode_contents(sc, 0); +} + +/* Extended Attributes */ + +/* + * Check that an extended attribute key can be looked up by hash. + * + * We use the extended attribute walk helper 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 int +xchk_xattr_actor( + struct xfs_scrub *sc, + struct xfs_inode *ip, + unsigned int attr_flags, + const unsigned char *name, + unsigned int namelen, + const void *value, + unsigned int valuelen, + void *priv) +{ + struct xfs_da_args args = { + .attr_filter = attr_flags & XFS_ATTR_NSP_ONDISK_MASK, + .geo = sc->mp->m_attr_geo, + .whichfork = XFS_ATTR_FORK, + .dp = ip, + .name = name, + .namelen = namelen, + .trans = sc->tp, + .valuelen = valuelen, + .owner = ip->i_ino, + }; + struct xchk_xattr_buf *ab; + int error = 0; + + ab = sc->buf; + + if (xchk_should_terminate(sc, &error)) + return error; + + if (attr_flags & ~XFS_ATTR_ONDISK_MASK) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + return -ECANCELED; + } + + if (attr_flags & XFS_ATTR_INCOMPLETE) { + /* Incomplete attr key, just mark the inode for preening. */ + xchk_ino_set_preen(sc, ip->i_ino); + return 0; + } + + /* Does this name make sense? */ + if (!xfs_attr_namecheck(attr_flags, name, namelen)) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + return -ECANCELED; + } + + /* Check parent pointer record. */ + if ((attr_flags & XFS_ATTR_PARENT) && + !xfs_parent_valuecheck(sc->mp, value, valuelen)) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + return -ECANCELED; + } + + /* + * Try to allocate enough memory to extract the attr value. If that + * doesn't work, return -EDEADLOCK as a signal to try again with a + * maximally sized buffer. + */ + error = xchk_setup_xattr_buf(sc, valuelen); + if (error == -ENOMEM) + error = -EDEADLOCK; + if (error) + return error; + + /* + * Parent pointers are matched on attr name and value, so we must + * supply the xfs_parent_rec here when confirming that the dabtree + * indexing works correctly. + */ + if (attr_flags & XFS_ATTR_PARENT) + memcpy(ab->value, value, valuelen); + + args.value = ab->value; + + /* + * Get the attr value to ensure that lookup can find this attribute + * through the dabtree indexing and that remote value retrieval also + * works correctly. + */ + xfs_attr_sethash(&args); + error = xfs_attr_get_ilocked(&args); + /* ENODATA means the hash lookup failed and the attr is bad */ + if (error == -ENODATA) + error = -EFSCORRUPTED; + if (!xchk_fblock_process_error(sc, XFS_ATTR_FORK, args.blkno, + &error)) + return error; + if (args.valuelen != valuelen) + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + + return 0; +} + +/* + * 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 + */ +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, + struct xfs_attr3_icleaf_hdr *leafhdr) +{ + struct xchk_xattr_buf *ab = sc->buf; + unsigned int mapsize = sc->mp->m_attr_geo->blksize; + int i; + + /* Construct bitmap of freemap contents. */ + bitmap_zero(ab->freemap, mapsize); + for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) { + if (!xchk_xattr_set_map(sc, ab->freemap, + leafhdr->freemap[i].base, + leafhdr->freemap[i].size)) + return false; + } + + /* Look for bits that are set in freemap and are marked in use. */ + return !bitmap_intersects(ab->freemap, ab->usedmap, mapsize); +} + +/* + * 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, + struct xfs_attr_leaf_entry *ent, + int idx, + unsigned int *usedbytes, + __u32 *last_hashval) +{ + struct xfs_mount *mp = ds->state->mp; + struct xchk_xattr_buf *ab = ds->sc->buf; + 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, ab->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; + struct xchk_xattr_buf *ab = 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(ab->usedmap, mp->m_attr_geo->blksize); + + /* Check all the padding. */ + if (xfs_has_crc(ds->sc->mp)) { + struct xfs_attr3_leafblock *leaf3 = bp->b_addr; + + if (leaf3->hdr.pad1 != 0 || leaf3->hdr.pad2 != 0 || + leaf3->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); + + /* + * Empty xattr leaf blocks mapped at block 0 are probably a byproduct + * of a race between setxattr and a log shutdown. Anywhere else in the + * attr fork is a corruption. + */ + if (leafhdr.count == 0) { + if (blk->blkno == 0) + xchk_da_set_preen(ds, level); + else + xchk_da_set_corrupt(ds, level); + } + 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, ab->usedmap, 0, hdrsize)) + xchk_da_set_corrupt(ds, level); + if (leafhdr.holes) + xchk_da_set_preen(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, ab->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, + ent, i, &usedbytes, &last_hashval); + + if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + goto out; + } + + if (!xchk_xattr_check_freemap(ds->sc, &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) +{ + struct xfs_mount *mp = ds->state->mp; + struct xfs_da_state_blk *blk = &ds->state->path.blk[level]; + struct xfs_attr_leaf_name_local *lentry; + struct xfs_attr_leaf_name_remote *rentry; + struct xfs_buf *bp; + struct xfs_attr_leaf_entry *ent; + xfs_dahash_t calc_hash; + xfs_dahash_t hash; + int nameidx; + int hdrsize; + int error; + + ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC); + + ent = xfs_attr3_leaf_entryp(blk->bp->b_addr) + blk->index; + + /* 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); + if (ent->flags & ~XFS_ATTR_ONDISK_MASK) { + xchk_da_set_corrupt(ds, level); + return 0; + } + if (!xfs_attr_check_namespace(ent->flags)) { + xchk_da_set_corrupt(ds, level); + return 0; + } + + 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_attr_hashval(mp, ent->flags, lentry->nameval, + lentry->namelen, + lentry->nameval + lentry->namelen, + be16_to_cpu(lentry->valuelen)); + } 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; + } + if (ent->flags & XFS_ATTR_PARENT) { + xchk_da_set_corrupt(ds, level); + goto out; + } + calc_hash = xfs_attr_hashval(mp, ent->flags, rentry->name, + rentry->namelen, NULL, + be32_to_cpu(rentry->valuelen)); + } + if (calc_hash != hash) + xchk_da_set_corrupt(ds, level); + +out: + return error; +} + +/* Check space usage of shortform attrs. */ +STATIC int +xchk_xattr_check_sf( + struct xfs_scrub *sc) +{ + struct xchk_xattr_buf *ab = sc->buf; + struct xfs_ifork *ifp = &sc->ip->i_af; + struct xfs_attr_sf_hdr *sf = ifp->if_data; + struct xfs_attr_sf_entry *sfe = xfs_attr_sf_firstentry(sf); + struct xfs_attr_sf_entry *next; + unsigned char *end = ifp->if_data + ifp->if_bytes; + int i; + int error = 0; + + bitmap_zero(ab->usedmap, ifp->if_bytes); + xchk_xattr_set_map(sc, ab->usedmap, 0, sizeof(*sf)); + + if ((unsigned char *)sfe > end) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, 0); + return 0; + } + + for (i = 0; i < sf->count; i++) { + unsigned char *name = sfe->nameval; + unsigned char *value = &sfe->nameval[sfe->namelen]; + + if (xchk_should_terminate(sc, &error)) + return error; + + next = xfs_attr_sf_nextentry(sfe); + if ((unsigned char *)next > end) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, 0); + break; + } + + /* + * Shortform entries do not set LOCAL or INCOMPLETE, so the + * only valid flag bits here are for namespaces. + */ + if (sfe->flags & ~XFS_ATTR_NSP_ONDISK_MASK) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, 0); + break; + } + + if (!xchk_xattr_set_map(sc, ab->usedmap, + (char *)sfe - (char *)sf, + sizeof(struct xfs_attr_sf_entry))) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, 0); + break; + } + + if (!xchk_xattr_set_map(sc, ab->usedmap, + (char *)name - (char *)sf, + sfe->namelen)) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, 0); + break; + } + + if (!xchk_xattr_set_map(sc, ab->usedmap, + (char *)value - (char *)sf, + sfe->valuelen)) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, 0); + break; + } + + sfe = next; + } + + return 0; +} + +/* Scrub the extended attribute metadata. */ +int +xchk_xattr( + struct xfs_scrub *sc) +{ + xfs_dablk_t last_checked = -1U; + int error = 0; + + if (!xfs_inode_hasattr(sc->ip)) + return -ENOENT; + + /* Allocate memory for xattr checking. */ + error = xchk_setup_xattr_buf(sc, 0); + if (error == -ENOMEM) + return -EDEADLOCK; + if (error) + return error; + + /* Check the physical structure of the xattr. */ + if (sc->ip->i_af.if_format == XFS_DINODE_FMT_LOCAL) + error = xchk_xattr_check_sf(sc); + else + error = xchk_da_btree(sc, XFS_ATTR_FORK, xchk_xattr_rec, + &last_checked); + if (error) + return error; + + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return 0; + + /* + * Look up every xattr in this file by name and hash. + * + * 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 = xchk_xattr_walk(sc, sc->ip, xchk_xattr_actor, NULL, NULL); + if (!xchk_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error)) + return error; + + return 0; +} |