From f5d55f03973f79a008bf8635452849f8ef589c23 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 27 Jan 2017 09:13:57 -0500 Subject: ceph: vet the target and parent inodes before updating dentry lease In a later patch, we're going to need to allow ceph_fill_trace to update the dentry's lease when the parent is not locked. This is potentially racy though -- by the time we get around to processing the trace, the parent may have already changed. Change update_dentry_lease to take a ceph_vino pointer and use that to ensure that the dentry's parent still matches it before updating the lease. Signed-off-by: Jeff Layton Reviewed-by: Yan, Zheng Signed-off-by: Ilya Dryomov --- fs/ceph/inode.c | 72 ++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 48 insertions(+), 24 deletions(-) (limited to 'fs/ceph/inode.c') diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 542e3c6b0f1b..f5111df561e4 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1016,7 +1016,9 @@ out: static void update_dentry_lease(struct dentry *dentry, struct ceph_mds_reply_lease *lease, struct ceph_mds_session *session, - unsigned long from_time) + unsigned long from_time, + struct ceph_vino *tgt_vino, + struct ceph_vino *dir_vino) { struct ceph_dentry_info *di = ceph_dentry(dentry); long unsigned duration = le32_to_cpu(lease->duration_ms); @@ -1024,13 +1026,27 @@ static void update_dentry_lease(struct dentry *dentry, long unsigned half_ttl = from_time + (duration * HZ / 2) / 1000; struct inode *dir; + /* + * Make sure dentry's inode matches tgt_vino. NULL tgt_vino means that + * we expect a negative dentry. + */ + if (!tgt_vino && d_really_is_positive(dentry)) + return; + + if (tgt_vino && (d_really_is_negative(dentry) || + !ceph_ino_compare(d_inode(dentry), tgt_vino))) + return; + spin_lock(&dentry->d_lock); dout("update_dentry_lease %p duration %lu ms ttl %lu\n", dentry, duration, ttl); - /* make lease_rdcache_gen match directory */ dir = d_inode(dentry->d_parent); + /* make sure parent matches dir_vino */ + if (!ceph_ino_compare(dir, dir_vino)) + goto out_unlock; + /* only track leases on regular dentries */ if (ceph_snap(dir) != CEPH_NOSNAP) goto out_unlock; @@ -1113,7 +1129,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req) struct ceph_mds_session *session = req->r_session; struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; struct inode *in = NULL; - struct ceph_vino vino; + struct ceph_vino tvino, dvino; struct ceph_fs_client *fsc = ceph_sb_to_client(sb); int err = 0; @@ -1154,8 +1170,8 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req) dname.name = rinfo->dname; dname.len = rinfo->dname_len; dname.hash = full_name_hash(parent, dname.name, dname.len); - vino.ino = le64_to_cpu(rinfo->targeti.in->ino); - vino.snap = le64_to_cpu(rinfo->targeti.in->snapid); + tvino.ino = le64_to_cpu(rinfo->targeti.in->ino); + tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid); retry_lookup: dn = d_lookup(parent, &dname); dout("d_lookup on parent=%p name=%.*s got %p\n", @@ -1172,8 +1188,8 @@ retry_lookup: } err = 0; } else if (d_really_is_positive(dn) && - (ceph_ino(d_inode(dn)) != vino.ino || - ceph_snap(d_inode(dn)) != vino.snap)) { + (ceph_ino(d_inode(dn)) != tvino.ino || + ceph_snap(d_inode(dn)) != tvino.snap)) { dout(" dn %p points to wrong inode %p\n", dn, d_inode(dn)); d_delete(dn); @@ -1187,10 +1203,10 @@ retry_lookup: } if (rinfo->head->is_target) { - vino.ino = le64_to_cpu(rinfo->targeti.in->ino); - vino.snap = le64_to_cpu(rinfo->targeti.in->snapid); + tvino.ino = le64_to_cpu(rinfo->targeti.in->ino); + tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid); - in = ceph_get_inode(sb, vino); + in = ceph_get_inode(sb, tvino); if (IS_ERR(in)) { err = PTR_ERR(in); goto done; @@ -1231,10 +1247,12 @@ retry_lookup: BUG_ON(!dn); BUG_ON(!dir); BUG_ON(d_inode(dn->d_parent) != dir); - BUG_ON(ceph_ino(dir) != - le64_to_cpu(rinfo->diri.in->ino)); - BUG_ON(ceph_snap(dir) != - le64_to_cpu(rinfo->diri.in->snapid)); + + dvino.ino = le64_to_cpu(rinfo->diri.in->ino); + dvino.snap = le64_to_cpu(rinfo->diri.in->snapid); + + BUG_ON(ceph_ino(dir) != dvino.ino); + BUG_ON(ceph_snap(dir) != dvino.snap); /* do we have a lease on the whole dir? */ have_dir_cap = @@ -1291,7 +1309,8 @@ retry_lookup: d_add(dn, NULL); update_dentry_lease(dn, rinfo->dlease, session, - req->r_request_started); + req->r_request_started, + NULL, &dvino); } goto done; } @@ -1314,9 +1333,13 @@ retry_lookup: have_lease = false; } - if (have_lease) + if (have_lease) { + tvino.ino = le64_to_cpu(rinfo->targeti.in->ino); + tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid); update_dentry_lease(dn, rinfo->dlease, session, - req->r_request_started); + req->r_request_started, + &tvino, &dvino); + } dout(" final dn %p\n", dn); } else if ((req->r_op == CEPH_MDS_OP_LOOKUPSNAP || req->r_op == CEPH_MDS_OP_MKSNAP) && @@ -1490,14 +1513,14 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, /* FIXME: release caps/leases if error occurs */ for (i = 0; i < rinfo->dir_nr; i++) { struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i; - struct ceph_vino vino; + struct ceph_vino tvino, dvino; dname.name = rde->name; dname.len = rde->name_len; dname.hash = full_name_hash(parent, dname.name, dname.len); - vino.ino = le64_to_cpu(rde->inode.in->ino); - vino.snap = le64_to_cpu(rde->inode.in->snapid); + tvino.ino = le64_to_cpu(rde->inode.in->ino); + tvino.snap = le64_to_cpu(rde->inode.in->snapid); if (rinfo->hash_order) { u32 hash = ceph_str_hash(ci->i_dir_layout.dl_dir_hash, @@ -1526,8 +1549,8 @@ retry_lookup: goto out; } } else if (d_really_is_positive(dn) && - (ceph_ino(d_inode(dn)) != vino.ino || - ceph_snap(d_inode(dn)) != vino.snap)) { + (ceph_ino(d_inode(dn)) != tvino.ino || + ceph_snap(d_inode(dn)) != tvino.snap)) { dout(" dn %p points to wrong inode %p\n", dn, d_inode(dn)); d_delete(dn); @@ -1539,7 +1562,7 @@ retry_lookup: if (d_really_is_positive(dn)) { in = d_inode(dn); } else { - in = ceph_get_inode(parent->d_sb, vino); + in = ceph_get_inode(parent->d_sb, tvino); if (IS_ERR(in)) { dout("new_inode badness\n"); d_drop(dn); @@ -1584,8 +1607,9 @@ retry_lookup: ceph_dentry(dn)->offset = rde->offset; + dvino = ceph_vino(d_inode(parent)); update_dentry_lease(dn, rde->lease, req->r_session, - req->r_request_started); + req->r_request_started, &tvino, &dvino); if (err == 0 && skipped == 0 && cache_ctl.index >= 0) { ret = fill_readdir_cache(d_inode(parent), dn, -- cgit v1.2.3