From: Darrick J. Wong <djwong@xxxxxxxxxx> Create a streamlined function to walk a file's xattrs, without all the cursor management stuff in the regular listxattr. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- fs/xfs/Makefile | 1 fs/xfs/scrub/attr.c | 125 +++++++------------ fs/xfs/scrub/listxattr.c | 309 ++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/listxattr.h | 17 +++ 4 files changed, 374 insertions(+), 78 deletions(-) create mode 100644 fs/xfs/scrub/listxattr.c create mode 100644 fs/xfs/scrub/listxattr.h diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index 6c9f6fe45815..ecc8120bff8b 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -164,6 +164,7 @@ xfs-y += $(addprefix scrub/, \ ialloc.o \ inode.o \ iscan.o \ + listxattr.o \ nlinks.o \ parent.o \ readdir.o \ diff --git a/fs/xfs/scrub/attr.c b/fs/xfs/scrub/attr.c index 07e8ca840745..ff83051c7981 100644 --- a/fs/xfs/scrub/attr.c +++ b/fs/xfs/scrub/attr.c @@ -21,6 +21,7 @@ #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. */ @@ -153,90 +154,81 @@ xchk_setup_xattr( /* 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_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. + * 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 void -xchk_xattr_listent( - struct xfs_attr_list_context *context, - int flags, - unsigned char *name, - int namelen, - int valuelen) +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 = { .op_flags = XFS_DA_OP_NOTIME, - .attr_filter = flags & XFS_ATTR_NSP_ONDISK_MASK, - .geo = context->dp->i_mount->m_attr_geo, + .attr_filter = attr_flags & XFS_ATTR_NSP_ONDISK_MASK, + .geo = sc->mp->m_attr_geo, .whichfork = XFS_ATTR_FORK, - .dp = context->dp, + .dp = ip, .name = name, .namelen = namelen, .hashval = xfs_da_hashname(name, namelen), - .trans = context->tp, + .trans = sc->tp, .valuelen = valuelen, - .owner = context->dp->i_ino, + .owner = ip->i_ino, }; struct xchk_xattr_buf *ab; - struct xchk_xattr *sx; int error = 0; - sx = container_of(context, struct xchk_xattr, context); - ab = sx->sc->buf; + ab = sc->buf; - if (xchk_should_terminate(sx->sc, &error)) { - context->seen_enough = error; - return; - } + if (xchk_should_terminate(sc, &error)) + return error; - if (flags & XFS_ATTR_INCOMPLETE) { + if (attr_flags & XFS_ATTR_INCOMPLETE) { /* Incomplete attr key, just mark the inode for preening. */ - xchk_ino_set_preen(sx->sc, context->dp->i_ino); - return; + xchk_ino_set_preen(sc, ip->i_ino); + return 0; } /* Only one namespace bit allowed. */ - if (hweight32(flags & XFS_ATTR_NSP_ONDISK_MASK) > 1) { - xchk_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK, args.blkno); - goto fail_xref; + if (hweight32(attr_flags & XFS_ATTR_NSP_ONDISK_MASK) > 1) { + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + return -ECANCELED; } /* Does this name make sense? */ if (!xfs_attr_namecheck(name, namelen)) { - xchk_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK, args.blkno); - goto fail_xref; + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + return -ECANCELED; } /* - * Local xattr values are stored in the attr leaf block, so we don't - * need to retrieve the value from a remote block to detect corruption - * problems. + * Local and shortform xattr values are stored in the attr leaf block, + * so we don't need to retrieve the value from a remote block to detect + * corruption problems. */ - if (flags & XFS_ATTR_LOCAL) - goto fail_xref; + if (value) + return 0; /* - * Try to allocate enough memory to extrat the attr value. If that - * doesn't work, we overload the seen_enough variable to convey - * the error message back to the main scrub function. + * 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(sx->sc, valuelen); + error = xchk_setup_xattr_buf(sc, valuelen); if (error == -ENOMEM) error = -EDEADLOCK; - if (error) { - context->seen_enough = error; - return; - } + if (error) + return error; args.value = ab->value; @@ -244,16 +236,13 @@ xchk_xattr_listent( /* ENODATA means the hash lookup failed and the attr is bad */ if (error == -ENODATA) error = -EFSCORRUPTED; - if (!xchk_fblock_process_error(sx->sc, XFS_ATTR_FORK, args.blkno, + if (!xchk_fblock_process_error(sc, XFS_ATTR_FORK, args.blkno, &error)) - goto fail_xref; + return error; 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; + xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno); + + return 0; } /* @@ -623,16 +612,6 @@ int xchk_xattr( struct xfs_scrub *sc) { - struct xchk_xattr sx = { - .sc = sc, - .context = { - .dp = sc->ip, - .tp = sc->tp, - .resynch = 1, - .put_listent = xchk_xattr_listent, - .allow_incomplete = true, - }, - }; xfs_dablk_t last_checked = -1U; int error = 0; @@ -661,12 +640,6 @@ xchk_xattr( /* * Look up every xattr in this file by name and hash. * - * 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 @@ -674,13 +647,9 @@ xchk_xattr( * iteration, which doesn't really follow the usual buffer * locking order. */ - error = xfs_attr_list_ilocked(&sx.context); + error = xchk_xattr_walk(sc, sc->ip, xchk_xattr_actor, NULL); if (!xchk_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error)) return error; - /* Did our listent function try to return any errors? */ - if (sx.context.seen_enough < 0) - return sx.context.seen_enough; - return 0; } diff --git a/fs/xfs/scrub/listxattr.c b/fs/xfs/scrub/listxattr.c new file mode 100644 index 000000000000..322715b2fd68 --- /dev/null +++ b/fs/xfs/scrub/listxattr.c @@ -0,0 +1,309 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2022-2023 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@xxxxxxxxxx> + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.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_trans.h" +#include "scrub/scrub.h" +#include "scrub/bitmap.h" +#include "scrub/listxattr.h" + +/* Call a function for every entry in a shortform xattr structure. */ +STATIC int +xchk_xattr_walk_sf( + struct xfs_scrub *sc, + struct xfs_inode *ip, + xchk_xattr_fn attr_fn, + void *priv) +{ + struct xfs_attr_shortform *sf; + struct xfs_attr_sf_entry *sfe; + unsigned int i; + int error; + + sf = (struct xfs_attr_shortform *)ip->i_af.if_u1.if_data; + for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) { + error = attr_fn(sc, ip, sfe->flags, sfe->nameval, sfe->namelen, + &sfe->nameval[sfe->namelen], sfe->valuelen, + priv); + if (error) + return error; + + sfe = xfs_attr_sf_nextentry(sfe); + } + + return 0; +} + +/* Call a function for every entry in this xattr leaf block. */ +STATIC int +xchk_xattr_walk_leaf_entries( + struct xfs_scrub *sc, + struct xfs_inode *ip, + xchk_xattr_fn attr_fn, + struct xfs_buf *bp, + void *priv) +{ + struct xfs_attr3_icleaf_hdr ichdr; + struct xfs_mount *mp = sc->mp; + struct xfs_attr_leafblock *leaf = bp->b_addr; + struct xfs_attr_leaf_entry *entry; + unsigned int i; + int error; + + xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf); + entry = xfs_attr3_leaf_entryp(leaf); + + for (i = 0; i < ichdr.count; entry++, i++) { + void *value; + unsigned char *name; + unsigned int namelen, valuelen; + + if (entry->flags & XFS_ATTR_LOCAL) { + struct xfs_attr_leaf_name_local *name_loc; + + name_loc = xfs_attr3_leaf_name_local(leaf, i); + name = name_loc->nameval; + namelen = name_loc->namelen; + value = &name_loc->nameval[name_loc->namelen]; + valuelen = be16_to_cpu(name_loc->valuelen); + } else { + struct xfs_attr_leaf_name_remote *name_rmt; + + name_rmt = xfs_attr3_leaf_name_remote(leaf, i); + name = name_rmt->name; + namelen = name_rmt->namelen; + value = NULL; + valuelen = be32_to_cpu(name_rmt->valuelen); + } + + error = attr_fn(sc, ip, entry->flags, name, namelen, value, + valuelen, priv); + if (error) + return error; + + } + + return 0; +} + +/* + * Call a function for every entry in a leaf-format xattr structure. Avoid + * memory allocations for the loop detector since there's only one block. + */ +STATIC int +xchk_xattr_walk_leaf( + struct xfs_scrub *sc, + struct xfs_inode *ip, + xchk_xattr_fn attr_fn, + void *priv) +{ + struct xfs_buf *leaf_bp; + int error; + + error = xfs_attr3_leaf_read(sc->tp, ip, ip->i_ino, 0, &leaf_bp); + if (error) + return error; + + error = xchk_xattr_walk_leaf_entries(sc, ip, attr_fn, leaf_bp, priv); + xfs_trans_brelse(sc->tp, leaf_bp); + return error; +} + +/* Find the leftmost leaf in the xattr dabtree. */ +STATIC int +xchk_xattr_find_leftmost_leaf( + struct xfs_scrub *sc, + struct xfs_inode *ip, + struct xbitmap *seen_blocks, + struct xfs_buf **leaf_bpp) +{ + struct xfs_da3_icnode_hdr nodehdr; + struct xfs_mount *mp = sc->mp; + struct xfs_trans *tp = sc->tp; + struct xfs_da_intnode *node; + struct xfs_da_node_entry *btree; + struct xfs_buf *bp; + xfs_failaddr_t fa; + xfs_dablk_t blkno = 0; + unsigned int expected_level = 0; + int error; + + for (;;) { + uint64_t len = 1; + uint16_t magic; + + /* Make sure we haven't seen this new block already. */ + if (xbitmap_test(seen_blocks, blkno, &len)) + return -EFSCORRUPTED; + + error = xfs_da3_node_read(tp, ip, blkno, &bp, XFS_ATTR_FORK); + if (error) + return error; + + node = bp->b_addr; + magic = be16_to_cpu(node->hdr.info.magic); + if (magic == XFS_ATTR_LEAF_MAGIC || + magic == XFS_ATTR3_LEAF_MAGIC) + break; + + error = -EFSCORRUPTED; + if (magic != XFS_DA_NODE_MAGIC && + magic != XFS_DA3_NODE_MAGIC) + goto out_buf; + + fa = xfs_da3_node_header_check(bp, ip->i_ino); + if (fa) + goto out_buf; + + xfs_da3_node_hdr_from_disk(mp, &nodehdr, node); + + if (nodehdr.count == 0 || nodehdr.level >= XFS_DA_NODE_MAXDEPTH) + goto out_buf; + + /* Check the level from the root node. */ + if (blkno == 0) + expected_level = nodehdr.level - 1; + else if (expected_level != nodehdr.level) + goto out_buf; + else + expected_level--; + + /* Remember that we've seen this node. */ + error = xbitmap_set(seen_blocks, blkno, 1); + if (error) + goto out_buf; + + /* Find the next level towards the leaves of the dabtree. */ + btree = nodehdr.btree; + blkno = be32_to_cpu(btree->before); + xfs_trans_brelse(tp, bp); + } + + error = -EFSCORRUPTED; + fa = xfs_attr3_leaf_header_check(bp, ip->i_ino); + if (fa) + goto out_buf; + + if (expected_level != 0) + goto out_buf; + + /* Remember that we've seen this leaf. */ + error = xbitmap_set(seen_blocks, blkno, 1); + if (error) + goto out_buf; + + *leaf_bpp = bp; + return 0; + +out_buf: + xfs_trans_brelse(tp, bp); + return error; +} + +/* Call a function for every entry in a node-format xattr structure. */ +STATIC int +xchk_xattr_walk_node( + struct xfs_scrub *sc, + struct xfs_inode *ip, + xchk_xattr_fn attr_fn, + void *priv) +{ + struct xfs_attr3_icleaf_hdr leafhdr; + struct xbitmap seen_blocks; + struct xfs_mount *mp = sc->mp; + struct xfs_attr_leafblock *leaf; + struct xfs_buf *leaf_bp; + int error; + + xbitmap_init(&seen_blocks); + + error = xchk_xattr_find_leftmost_leaf(sc, ip, &seen_blocks, &leaf_bp); + if (error) + goto out_bitmap; + + for (;;) { + uint64_t len; + + error = xchk_xattr_walk_leaf_entries(sc, ip, attr_fn, leaf_bp, + priv); + if (error) + goto out_leaf; + + /* Find the right sibling of this leaf block. */ + leaf = leaf_bp->b_addr; + xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf); + if (leafhdr.forw == 0) + goto out_leaf; + + xfs_trans_brelse(sc->tp, leaf_bp); + + /* Make sure we haven't seen this new leaf already. */ + len = 1; + if (xbitmap_test(&seen_blocks, leafhdr.forw, &len)) + goto out_bitmap; + + error = xfs_attr3_leaf_read(sc->tp, ip, ip->i_ino, + leafhdr.forw, &leaf_bp); + if (error) + goto out_bitmap; + + /* Remember that we've seen this new leaf. */ + error = xbitmap_set(&seen_blocks, leafhdr.forw, 1); + if (error) + goto out_leaf; + } + +out_leaf: + xfs_trans_brelse(sc->tp, leaf_bp); +out_bitmap: + xbitmap_destroy(&seen_blocks); + return error; +} + +/* + * Call a function for every extended attribute in a file. + * + * Callers must hold the ILOCK. No validation or cursor restarts allowed. + * Returns -EFSCORRUPTED on any problem, including loops in the dabtree. + */ +int +xchk_xattr_walk( + struct xfs_scrub *sc, + struct xfs_inode *ip, + xchk_xattr_fn attr_fn, + void *priv) +{ + int error; + + ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); + + if (!xfs_inode_hasattr(ip)) + return 0; + + if (ip->i_af.if_format == XFS_DINODE_FMT_LOCAL) + return xchk_xattr_walk_sf(sc, ip, attr_fn, priv); + + /* attr functions require that the attr fork is loaded */ + error = xfs_iread_extents(sc->tp, ip, XFS_ATTR_FORK); + if (error) + return error; + + if (xfs_attr_is_leaf(ip)) + return xchk_xattr_walk_leaf(sc, ip, attr_fn, priv); + + return xchk_xattr_walk_node(sc, ip, attr_fn, priv); +} diff --git a/fs/xfs/scrub/listxattr.h b/fs/xfs/scrub/listxattr.h new file mode 100644 index 000000000000..fce419255dc0 --- /dev/null +++ b/fs/xfs/scrub/listxattr.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2022-2023 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@xxxxxxxxxx> + */ +#ifndef __XFS_SCRUB_LISTXATTR_H__ +#define __XFS_SCRUB_LISTXATTR_H__ + +typedef int (*xchk_xattr_fn)(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); + +int xchk_xattr_walk(struct xfs_scrub *sc, struct xfs_inode *ip, + xchk_xattr_fn attr_fn, void *priv); + +#endif /* __XFS_SCRUB_LISTXATTR_H__ */