[01/22] xfs: check dirents have parent pointers

Message ID	170404841764.1757392.11351513012455132613.stgit@frogsfrogsfrogs (mailing list archive)
State	Superseded, archived
Headers	show Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C5704BE4D for <linux-xfs@vger.kernel.org>; Sun, 31 Dec 2023 20:53:27 +0000 (UTC) Date: Sun, 31 Dec 2023 12:53:27 -0800 Subject: [PATCH 01/22] xfs: check dirents have parent pointers From: "Darrick J. Wong" <djwong@kernel.org> To: djwong@kernel.org Cc: catherine.hoang@oracle.com, allison.henderson@oracle.com, linux-xfs@vger.kernel.org Message-ID: <170404841764.1757392.11351513012455132613.stgit@frogsfrogsfrogs> In-Reply-To: <170404841699.1757392.2057683072581072853.stgit@frogsfrogsfrogs> References: <170404841699.1757392.2057683072581072853.stgit@frogsfrogsfrogs> User-Agent: StGit/0.19 Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit
Series	[01/22] xfs: check dirents have parent pointers \| expand [01/22] xfs: check dirents have parent pointers [02/22] xfs: deferred scrub of dirents [03/22] xfs: create a parent pointer walk function for scrubbers [04/22] xfs: scrub parent pointers [05/22] xfs: deferred scrub of parent pointers [06/22] xfs: walk directory parent pointers to determine backref count [07/22] xfs: add raw parent pointer apis to support repair [08/22] xfs: set child file owner in xfs_da_args when changing parent pointers [09/22] xfs: salvage parent pointers when rebuilding xattr structures [10/22] xfs: replace namebuf with parent pointer in directory repair [11/22] xfs: repair directories by scanning directory parent pointers [12/22] xfs: implement live updates for directory repairs [13/22] xfs: replay unlocked parent pointer updates that accrue during xattr repair [14/22] xfs: replace namebuf with parent pointer in parent pointer repair [15/22] xfs: repair directory parent pointers by scanning for dirents [16/22] xfs: implement live updates for parent pointer repairs [17/22] xfs: remove pointless unlocked assertion [18/22] xfs: split xfs_bmap_add_attrfork into two pieces [19/22] xfs: actually rebuild the parent pointer xattrs [20/22] xfs: adapt the orphanage code to handle parent pointers [21/22] xfs: repair link count of nondirectories after rebuilding parent pointers [22/22] xfs: inode repair should ensure there's an attr fork to store parent pointers

diff --git a/fs/xfs/libxfs/xfs_parent.c b/fs/xfs/libxfs/xfs_parent.c index 48a2dfcc465fa..09495eb368e2b 100644 --- a/fs/xfs/libxfs/xfs_parent.c +++ b/fs/xfs/libxfs/xfs_parent.c @@ -366,3 +366,57 @@ xfs_parent_irec_hashname( irec->p_namehash = xfs_dir2_hashname(mp, &dname); } + +static inline void +xfs_parent_scratch_init( + struct xfs_trans *tp, + struct xfs_inode *ip, + const struct xfs_parent_name_irec *pptr, + struct xfs_parent_scratch *scr) +{ + memset(&scr->args, 0, sizeof(struct xfs_da_args)); + scr->args.attr_filter = XFS_ATTR_PARENT; + scr->args.dp = ip; + scr->args.geo = ip->i_mount->m_attr_geo; + scr->args.name = (const unsigned char *)&scr->rec; + scr->args.namelen = sizeof(struct xfs_parent_name_rec); + scr->args.op_flags = XFS_DA_OP_NVLOOKUP; + scr->args.trans = tp; + scr->args.value = (void *)pptr->p_name; + scr->args.valuelen = pptr->p_namelen; + scr->args.whichfork = XFS_ATTR_FORK; + scr->args.hashval = xfs_da_hashname((const void *)&scr->rec, + sizeof(struct xfs_parent_name_rec)); +} + +/* + * Look up the @name associated with the parent pointer (@pptr) of @ip. + * Caller must hold at least ILOCK_SHARED. Returns 0 if the pointer is found, + * -ENOATTR if there is no match, or a negative errno. The scratchpad need not + * be initialized. + */ +int +xfs_parent_lookup( + struct xfs_trans *tp, + struct xfs_inode *ip, + const struct xfs_parent_name_irec *pptr, + struct xfs_parent_scratch *scr) +{ + int error; + + /* + * Make sure the attr fork iext tree is loaded in transaction context + * before we start down the rest of the call path. + */ + if (xfs_inode_hasattr(ip)) { + error = xfs_iread_extents(tp, ip, XFS_ATTR_FORK); + if (error) + return error; + } + + xfs_parent_irec_to_disk(&scr->rec, pptr); + xfs_parent_scratch_init(tp, ip, pptr, scr); + scr->args.op_flags |= XFS_DA_OP_OKNOENT; + + return xfs_attr_get_ilocked(&scr->args); +} diff --git a/fs/xfs/libxfs/xfs_parent.h b/fs/xfs/libxfs/xfs_parent.h index e43ae5a7df826..e4443da1d86f2 100644 --- a/fs/xfs/libxfs/xfs_parent.h +++ b/fs/xfs/libxfs/xfs_parent.h @@ -152,4 +152,14 @@ void xfs_parent_irec_hashname(struct xfs_mount *mp, bool xfs_parent_verify_irec(struct xfs_mount *mp, const struct xfs_parent_name_irec *irec); +/* Scratchpad memory so that raw parent operations don't burn stack space. */ +struct xfs_parent_scratch { + struct xfs_parent_name_rec rec; + struct xfs_da_args args; +}; + +int xfs_parent_lookup(struct xfs_trans *tp, struct xfs_inode *ip, + const struct xfs_parent_name_irec *pptr, + struct xfs_parent_scratch *scratch); + #endif /* __XFS_PARENT_H__ */ diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c index 3fe6ffcf9c062..88370804025c4 100644 --- a/fs/xfs/scrub/dir.c +++ b/fs/xfs/scrub/dir.c @@ -16,6 +16,8 @@ #include "xfs_dir2.h" #include "xfs_dir2_priv.h" #include "xfs_health.h" +#include "xfs_attr.h" +#include "xfs_parent.h" #include "scrub/scrub.h" #include "scrub/common.h" #include "scrub/dabtree.h" @@ -41,6 +43,20 @@ xchk_setup_directory( /* Directories */ +struct xchk_dir { + struct xfs_scrub *sc; + + /* Scratch buffer for scanning pptr xattrs */ + struct xfs_parent_name_irec pptr; + + /* xattr key and da args for parent pointer validation. */ + struct xfs_parent_scratch pptr_scratch; + + /* Name buffer for dirent revalidation. */ + uint8_t namebuf[MAXNAMELEN]; + +}; + /* Scrub a directory entry. */ /* Check that an inode's mode matches a given XFS_DIR3_FT_* type. */ @@ -63,6 +79,94 @@ xchk_dir_check_ftype( xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset); } +/* + * Try to lock a child file for checking parent pointers. Returns the inode + * flags for the locks we now hold, or zero if we failed. + */ +STATIC unsigned int +xchk_dir_lock_child( + struct xfs_scrub *sc, + struct xfs_inode *ip) +{ + if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) + return 0; + + if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) { + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return 0; + } + + if (!xfs_inode_has_attr_fork(ip) || !xfs_need_iread_extents(&ip->i_af)) + return XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED; + + xfs_iunlock(ip, XFS_ILOCK_SHARED); + + if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) { + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return 0; + } + + return XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL; +} + +/* Check the backwards link (parent pointer) associated with this dirent. */ +STATIC int +xchk_dir_parent_pointer( + struct xchk_dir *sd, + const struct xfs_name *name, + struct xfs_inode *ip) +{ + struct xfs_scrub *sc = sd->sc; + int error; + + sd->pptr.p_ino = sc->ip->i_ino; + sd->pptr.p_gen = VFS_I(sc->ip)->i_generation; + sd->pptr.p_namelen = name->len; + memcpy(sd->pptr.p_name, name->name, name->len); + xfs_parent_irec_hashname(sc->mp, &sd->pptr); + + error = xfs_parent_lookup(sc->tp, ip, &sd->pptr, &sd->pptr_scratch); + if (error == -ENOATTR) + xchk_fblock_xref_set_corrupt(sc, XFS_DATA_FORK, 0); + + return 0; +} + +/* Look for a parent pointer matching this dirent, if the child isn't busy. */ +STATIC int +xchk_dir_check_pptr_fast( + struct xchk_dir *sd, + xfs_dir2_dataptr_t dapos, + const struct xfs_name *name, + struct xfs_inode *ip) +{ + struct xfs_scrub *sc = sd->sc; + unsigned int lockmode; + int error; + + /* dot and dotdot entries do not have parent pointers */ + if (xfs_dir2_samename(name, &xfs_name_dot) || + xfs_dir2_samename(name, &xfs_name_dotdot)) + return 0; + + /* No self-referential non-dot or dotdot dirents. */ + if (ip == sc->ip) { + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0); + return -ECANCELED; + } + + /* Try to lock the inode. */ + lockmode = xchk_dir_lock_child(sc, ip); + if (!lockmode) { + xchk_set_incomplete(sc); + return -ECANCELED; + } + + error = xchk_dir_parent_pointer(sd, name, ip); + xfs_iunlock(ip, lockmode); + return error; +} + /* * Scrub a single directory entry. * @@ -80,6 +184,7 @@ xchk_dir_actor( { struct xfs_mount *mp = dp->i_mount; struct xfs_inode *ip; + struct xchk_dir *sd = priv; xfs_ino_t lookup_ino; xfs_dablk_t offset; int error = 0; @@ -146,6 +251,14 @@ xchk_dir_actor( goto out; xchk_dir_check_ftype(sc, offset, ip, name->type); + + if (xfs_has_parent(mp)) { + error = xchk_dir_check_pptr_fast(sd, dapos, name, ip); + if (error) + goto out_rele; + } + +out_rele: xchk_irele(sc, ip); out: if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) @@ -767,6 +880,7 @@ int xchk_directory( struct xfs_scrub *sc) { + struct xchk_dir *sd; int error; if (!S_ISDIR(VFS_I(sc->ip)->i_mode)) @@ -799,8 +913,14 @@ xchk_directory( if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) return 0; + sd = kvzalloc(sizeof(struct xchk_dir), XCHK_GFP_FLAGS); + if (!sd) + return -ENOMEM; + sd->sc = sc; + /* Look up every name in this directory by hash. */ - error = xchk_dir_walk(sc, sc->ip, xchk_dir_actor, NULL); + error = xchk_dir_walk(sc, sc->ip, xchk_dir_actor, sd); + kvfree(sd); if (error && error != -ECANCELED) return error;

[01/22] xfs: check dirents have parent pointers

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