From: Darrick J. Wong Date: Mon, 15 Apr 2024 21:54:57 +0000 (-0700) Subject: xfs: ensure dentry consistency when the orphanage adopts a file X-Git-Tag: io_uring-6.10-20240523~19^2~64^2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=73597e3e42b4a15030e6f93b71b53a04377ea419;p=linux-2.6-block.git 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 Reviewed-by: Christoph Hellwig --- diff --git a/fs/xfs/scrub/orphanage.c b/fs/xfs/scrub/orphanage.c index 41733be3ef45..885b7d478a0a 100644 --- a/fs/xfs/scrub/orphanage.c +++ b/fs/xfs/scrub/orphanage.c @@ -418,6 +418,90 @@ xrep_adoption_compute_name( 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_adoption_check_dcache( + struct xrep_adoption *adopt) +{ + struct qstr qname = QSTR_INIT(adopt->xname->name, + adopt->xname->len); + struct dentry *d_orphanage, *d_child; + int error = 0; + + d_orphanage = d_find_alias(VFS_I(adopt->sc->orphanage)); + if (!d_orphanage) + return 0; + + d_child = d_hash_and_lookup(d_orphanage, &qname); + if (d_child) { + trace_xrep_adoption_check_child(adopt->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? There shouldn't be a hashed dentry with a parent since + * the file had nonzero nlink but wasn't connected to any parent dir. + */ + d_child = d_find_alias(VFS_I(adopt->sc->ip)); + if (!d_child) + return 0; + + trace_xrep_adoption_check_alias(adopt->sc->mp, d_child); + + if (d_child->d_parent && !d_unhashed(d_child)) { + ASSERT(d_child->d_parent == NULL || d_unhashed(d_child)); + error = -EFSCORRUPTED; + } + + dput(d_child); + return error; +} + +/* + * 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 void +xrep_adoption_zap_dcache( + struct xrep_adoption *adopt) +{ + struct qstr qname = QSTR_INIT(adopt->xname->name, + adopt->xname->len); + struct dentry *d_orphanage, *d_child; + + d_orphanage = d_find_alias(VFS_I(adopt->sc->orphanage)); + if (!d_orphanage) + return; + + d_child = d_hash_and_lookup(d_orphanage, &qname); + while (d_child != NULL) { + trace_xrep_adoption_invalidate_child(adopt->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); +} + /* * Move the current file to the orphanage under the computed name. * @@ -435,6 +519,10 @@ xrep_adoption_move( trace_xrep_adoption_reparent(sc->orphanage, adopt->xname, sc->ip->i_ino); + error = xrep_adoption_check_dcache(adopt); + if (error) + return error; + /* Create the new name in the orphanage. */ error = xfs_dir_createname(sc->tp, sc->orphanage, adopt->xname, sc->ip->i_ino, adopt->orphanage_blkres); @@ -465,6 +553,9 @@ xrep_adoption_move( * recorded in the log. */ xfs_dir_update_hook(sc->orphanage, sc->ip, 1, adopt->xname); + + /* Remove negative dentries from the lost+found's dcache */ + xrep_adoption_zap_dcache(adopt); return 0; } diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index 2a4c54f7992a..668da6ff2ca2 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -2669,6 +2669,48 @@ 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, flags) + __field(unsigned long, ino) + __field(bool, positive) + __field(unsigned long, parent_ino) + __field(unsigned int, namelen) + __dynamic_array(char, name, dentry->d_name.len) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->flags = dentry->d_flags; + __entry->positive = d_is_positive(dentry); + if (dentry->d_parent && d_inode(dentry->d_parent)) + __entry->parent_ino = d_inode(dentry->d_parent)->i_ino; + else + __entry->parent_ino = -1UL; + __entry->ino = d_inode(dentry) ? d_inode(dentry)->i_ino : 0; + __entry->namelen = dentry->d_name.len; + memcpy(__get_str(name), dentry->d_name.name, dentry->d_name.len); + ), + TP_printk("dev %d:%d flags 0x%x positive? %d parent_ino 0x%lx ino 0x%lx name '%.*s'", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->flags, + __entry->positive, + __entry->parent_ino, + __entry->ino, + __entry->namelen, + __get_str(name)) +); +#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_adoption_check_child); +DEFINE_REPAIR_DENTRY_EVENT(xrep_adoption_check_alias); +DEFINE_REPAIR_DENTRY_EVENT(xrep_adoption_check_dentry); +DEFINE_REPAIR_DENTRY_EVENT(xrep_adoption_invalidate_child); + #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */ #endif /* _TRACE_XFS_SCRUB_TRACE_H */