From 9678c9e283f964c7b8dddd1c3933b7f01dc8701e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 18 Jul 2022 17:54:43 -0700 Subject: xfs: ensure dentry consistency when the orphanage adopts a file When the orphanage adopts a file, that file becomes a child of the orphanage. The dentry cache may have entries for the orphanage directory and the name we've chosen, so (1) make sure we abort if the dcache has a positive entry because something's not right; and (2) invalidate and purge negative dentries if the adoption goes through. Signed-off-by: Darrick J. Wong --- fs/xfs/scrub/orphanage.c | 100 ++++++++++++++++++++++++++++++++++++++++++++--- fs/xfs/scrub/trace.h | 32 +++++++++++++++ 2 files changed, 127 insertions(+), 5 deletions(-) diff --git a/fs/xfs/scrub/orphanage.c b/fs/xfs/scrub/orphanage.c index 1fe7935433bf..08ff273dbb39 100644 --- a/fs/xfs/scrub/orphanage.c +++ b/fs/xfs/scrub/orphanage.c @@ -356,6 +356,89 @@ xrep_orphanage_adoption_prep( return 0; } +/* + * Make sure the dcache does not have a positive dentry for the name we've + * chosen. The caller should have checked with the ondisk directory, so any + * discrepancy is a sign that something is seriously wrong. + */ +static int +xrep_orphanage_check_dcache( + struct xrep_orphanage_req *orph) +{ + struct qstr qname = QSTR_INIT(orph->xname.name, + orph->xname.len); + struct dentry *d_orphanage, *d_child, *dentry; + int error = 0; + + d_orphanage = d_find_alias(VFS_I(orph->sc->orphanage)); + if (!d_orphanage) + return 0; + + d_child = d_hash_and_lookup(d_orphanage, &qname); + if (d_child) { + trace_xrep_orphanage_check_child(orph->sc->mp, d_child); + + if (d_is_positive(d_child)) { + ASSERT(d_is_negative(d_child)); + error = -EFSCORRUPTED; + } + + dput(d_child); + } + + dput(d_orphanage); + if (error) + return error; + + /* + * Do we need to update d_parent of the dentry for the file being + * repaired? In theory there shouldn't be one since the file had + * nonzero nlink but wasn't connected to any parent dir. + */ + dentry = d_find_alias(VFS_I(orph->sc->ip)); + if (dentry) { + trace_xrep_orphanage_check_dentry(orph->sc->mp, d_child); + ASSERT(dentry->d_parent == NULL); + + dput(dentry); + return -EFSCORRUPTED; + } + + return 0; +} + +/* + * Remove all negative dentries from the dcache. There should not be any + * positive entries, since we've maintained our lock on the orphanage + * directory. + */ +static int +xrep_orphanage_zap_dcache( + struct xrep_orphanage_req *orph) +{ + struct qstr qname = QSTR_INIT(orph->xname.name, + orph->xname.len); + struct dentry *d_orphanage, *d_child; + int error = 0; + + d_orphanage = d_find_alias(VFS_I(orph->sc->orphanage)); + if (!d_orphanage) + return 0; + + d_child = d_hash_and_lookup(d_orphanage, &qname); + while (d_child != NULL) { + trace_xrep_orphanage_zap_child(orph->sc->mp, d_child); + + ASSERT(d_is_negative(d_child)); + d_invalidate(d_child); + dput(d_child); + d_child = d_lookup(d_orphanage, &qname); + } + + dput(d_orphanage); + return error; +} + /* * Move the current file to the orphanage. * @@ -375,6 +458,10 @@ xrep_orphanage_adopt( trace_xrep_orphanage_adopt(sc->orphanage, &orph->xname, sc->ip->i_ino); + error = xrep_orphanage_check_dcache(orph); + if (error) + return error; + /* * Create the new name in the orphanage, and bump the link count of * the orphanage if we just added a directory. @@ -390,12 +477,15 @@ xrep_orphanage_adopt( xfs_bumplink(sc->tp, sc->orphanage); xfs_trans_log_inode(sc->tp, sc->orphanage, XFS_ILOG_CORE); - if (!isdir) - return 0; + if (isdir) { + /* Replace the dotdot entry in the child directory. */ + error = xfs_dir_replace(sc->tp, sc->ip, &xfs_name_dotdot, + sc->orphanage->i_ino, orph->child_blkres); + if (error) + return error; + } - /* Replace the dotdot entry in the child directory. */ - return xfs_dir_replace(sc->tp, sc->ip, &xfs_name_dotdot, - sc->orphanage->i_ino, orph->child_blkres); + return xrep_orphanage_zap_dcache(orph); } /* Release the orphanage. */ diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index 8d5067b4e3d9..f86a287a3158 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -2534,6 +2534,38 @@ TRACE_EVENT(xrep_nlinks_set_record, __entry->children) ); +DECLARE_EVENT_CLASS(xrep_dentry_class, + TP_PROTO(struct xfs_mount *mp, const struct dentry *dentry), + TP_ARGS(mp, dentry), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(unsigned int, type) + __field(unsigned long, ino) + __field(bool, positive) + __field(bool, has_parent) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->type = __d_entry_type(dentry); + __entry->positive = d_is_positive(dentry); + __entry->has_parent = dentry->d_parent != NULL; + __entry->ino = d_inode(dentry) ? d_inode(dentry)->i_ino : 0; + ), + TP_printk("dev %d:%d type 0x%x positive? %d parent? %d ino 0x%lx", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->type, + __entry->positive, + __entry->has_parent, + __entry->ino) +); +#define DEFINE_REPAIR_DENTRY_EVENT(name) \ +DEFINE_EVENT(xrep_dentry_class, name, \ + TP_PROTO(struct xfs_mount *mp, const struct dentry *dentry), \ + TP_ARGS(mp, dentry)) +DEFINE_REPAIR_DENTRY_EVENT(xrep_orphanage_check_child); +DEFINE_REPAIR_DENTRY_EVENT(xrep_orphanage_check_dentry); +DEFINE_REPAIR_DENTRY_EVENT(xrep_orphanage_zap_child); + #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */ -- cgit v1.2.3