diff options
Diffstat (limited to 'fs/xfs/scrub/dir.c')
-rw-r--r-- | fs/xfs/scrub/dir.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c new file mode 100644 index 000000000000..da0f4b1308b0 --- /dev/null +++ b/fs/xfs/scrub/dir.c @@ -0,0 +1,331 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong <darrick.wong@oracle.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#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_icache.h" +#include "xfs_itable.h" +#include "xfs_da_format.h" +#include "xfs_da_btree.h" +#include "xfs_dir2.h" +#include "xfs_dir2_priv.h" +#include "xfs_ialloc.h" +#include "scrub/xfs_scrub.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/trace.h" +#include "scrub/dabtree.h" + +/* Set us up to scrub directories. */ +int +xfs_scrub_setup_directory( + struct xfs_scrub_context *sc, + struct xfs_inode *ip) +{ + return xfs_scrub_setup_inode_contents(sc, ip, 0); +} + +/* Directories */ + +/* Scrub a directory entry. */ + +struct xfs_scrub_dir_ctx { + /* VFS fill-directory iterator */ + struct dir_context dir_iter; + + struct xfs_scrub_context *sc; +}; + +/* Check that an inode's mode matches a given DT_ type. */ +STATIC int +xfs_scrub_dir_check_ftype( + struct xfs_scrub_dir_ctx *sdc, + xfs_fileoff_t offset, + xfs_ino_t inum, + int dtype) +{ + struct xfs_mount *mp = sdc->sc->mp; + struct xfs_inode *ip; + int ino_dtype; + int error = 0; + + if (!xfs_sb_version_hasftype(&mp->m_sb)) { + if (dtype != DT_UNKNOWN && dtype != DT_DIR) + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, + offset); + goto out; + } + + /* + * Grab the inode pointed to by the dirent. We release the + * inode before we cancel the scrub transaction. Since we're + * don't know a priori that releasing the inode won't trigger + * eofblocks cleanup (which allocates what would be a nested + * transaction), we can't use DONTCACHE here because DONTCACHE + * inodes can trigger immediate inactive cleanup of the inode. + */ + error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip); + if (!xfs_scrub_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset, + &error)) + goto out; + + /* Convert mode to the DT_* values that dir_emit uses. */ + ino_dtype = xfs_dir3_get_dtype(mp, + xfs_mode_to_ftype(VFS_I(ip)->i_mode)); + if (ino_dtype != dtype) + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset); + iput(VFS_I(ip)); +out: + return error; +} + +/* + * Scrub a single directory entry. + * + * We use the VFS directory iterator (i.e. readdir) to call this + * function for every directory entry in a directory. Once we're here, + * we check the inode number to make sure it's sane, then we check that + * we can look up this filename. Finally, we check the ftype. + */ +STATIC int +xfs_scrub_dir_actor( + struct dir_context *dir_iter, + const char *name, + int namelen, + loff_t pos, + u64 ino, + unsigned type) +{ + struct xfs_mount *mp; + struct xfs_inode *ip; + struct xfs_scrub_dir_ctx *sdc; + struct xfs_name xname; + xfs_ino_t lookup_ino; + xfs_dablk_t offset; + int error = 0; + + sdc = container_of(dir_iter, struct xfs_scrub_dir_ctx, dir_iter); + ip = sdc->sc->ip; + mp = ip->i_mount; + offset = xfs_dir2_db_to_da(mp->m_dir_geo, + xfs_dir2_dataptr_to_db(mp->m_dir_geo, pos)); + + /* Does this inode number make sense? */ + if (!xfs_verify_dir_ino(mp, ino)) { + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset); + goto out; + } + + if (!strncmp(".", name, namelen)) { + /* If this is "." then check that the inum matches the dir. */ + if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR) + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, + offset); + if (ino != ip->i_ino) + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, + offset); + } else if (!strncmp("..", name, namelen)) { + /* + * If this is ".." in the root inode, check that the inum + * matches this dir. + */ + if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR) + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, + offset); + if (ip->i_ino == mp->m_sb.sb_rootino && ino != ip->i_ino) + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, + offset); + } + + /* Verify that we can look up this name by hash. */ + xname.name = name; + xname.len = namelen; + xname.type = XFS_DIR3_FT_UNKNOWN; + + error = xfs_dir_lookup(sdc->sc->tp, ip, &xname, &lookup_ino, NULL); + if (!xfs_scrub_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset, + &error)) + goto fail_xref; + if (lookup_ino != ino) { + xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset); + goto out; + } + + /* Verify the file type. This function absorbs error codes. */ + error = xfs_scrub_dir_check_ftype(sdc, offset, lookup_ino, type); + if (error) + goto out; +out: + return error; +fail_xref: + return error; +} + +/* Scrub a directory btree record. */ +STATIC int +xfs_scrub_dir_rec( + struct xfs_scrub_da_btree *ds, + int level, + void *rec) +{ + struct xfs_mount *mp = ds->state->mp; + struct xfs_dir2_leaf_entry *ent = rec; + struct xfs_inode *dp = ds->dargs.dp; + struct xfs_dir2_data_entry *dent; + struct xfs_buf *bp; + xfs_ino_t ino; + xfs_dablk_t rec_bno; + xfs_dir2_db_t db; + xfs_dir2_data_aoff_t off; + xfs_dir2_dataptr_t ptr; + xfs_dahash_t calc_hash; + xfs_dahash_t hash; + unsigned int tag; + int error; + + /* Check the hash of the entry. */ + error = xfs_scrub_da_btree_hash(ds, level, &ent->hashval); + if (error) + goto out; + + /* Valid hash pointer? */ + ptr = be32_to_cpu(ent->address); + if (ptr == 0) + return 0; + + /* Find the directory entry's location. */ + db = xfs_dir2_dataptr_to_db(mp->m_dir_geo, ptr); + off = xfs_dir2_dataptr_to_off(mp->m_dir_geo, ptr); + rec_bno = xfs_dir2_db_to_da(mp->m_dir_geo, db); + + if (rec_bno >= mp->m_dir_geo->leafblk) { + xfs_scrub_da_set_corrupt(ds, level); + goto out; + } + error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp); + if (!xfs_scrub_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno, + &error)) + goto out; + if (!bp) { + xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + goto out; + } + + /* Retrieve the entry, sanity check it, and compare hashes. */ + dent = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off); + ino = be64_to_cpu(dent->inumber); + hash = be32_to_cpu(ent->hashval); + tag = be16_to_cpup(dp->d_ops->data_entry_tag_p(dent)); + if (!xfs_verify_dir_ino(mp, ino) || tag != off) + xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + if (dent->namelen == 0) { + xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + goto out_relse; + } + calc_hash = xfs_da_hashname(dent->name, dent->namelen); + if (calc_hash != hash) + xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + +out_relse: + xfs_trans_brelse(ds->dargs.trans, bp); +out: + return error; +} + +/* Scrub a whole directory. */ +int +xfs_scrub_directory( + struct xfs_scrub_context *sc) +{ + struct xfs_scrub_dir_ctx sdc = { + .dir_iter.actor = xfs_scrub_dir_actor, + .dir_iter.pos = 0, + .sc = sc, + }; + size_t bufsize; + loff_t oldpos; + int error; + + if (!S_ISDIR(VFS_I(sc->ip)->i_mode)) + return -ENOENT; + + /* Plausible size? */ + if (sc->ip->i_d.di_size < xfs_dir2_sf_hdr_size(0)) { + xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL); + goto out; + } + + /* Check directory tree structure */ + error = xfs_scrub_da_btree(sc, XFS_DATA_FORK, xfs_scrub_dir_rec); + if (error) + return error; + + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return error; + + /* + * Check that every dirent we see can also be looked up by hash. + * Userspace usually asks for a 32k buffer, so we will too. + */ + bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, + sc->ip->i_d.di_size); + + /* + * Look up every name in this directory by hash. + * + * Use the xfs_readdir function to call xfs_scrub_dir_actor on + * every directory entry in this directory. In _actor, we check + * the name, inode number, and ftype (if applicable) of the + * entry. xfs_readdir uses the VFS filldir functions to provide + * iteration context. + * + * The VFS grabs a read or write lock via i_rwsem before it reads + * or writes to a directory. If we've gotten this far we've + * already obtained IOLOCK_EXCL, which (since 4.10) is the same as + * getting a write lock on i_rwsem. Therefore, it is safe for us + * to drop the ILOCK here in order to reuse the _readdir and + * _dir_lookup routines, which do their own ILOCK locking. + */ + oldpos = 0; + sc->ilock_flags &= ~XFS_ILOCK_EXCL; + xfs_iunlock(sc->ip, XFS_ILOCK_EXCL); + while (true) { + error = xfs_readdir(sc->tp, sc->ip, &sdc.dir_iter, bufsize); + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, + &error)) + goto out; + if (oldpos == sdc.dir_iter.pos) + break; + oldpos = sdc.dir_iter.pos; + } + +out: + return error; +} |