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ceph: snapshot nfs re-export
To support snapshot nfs re-export, we need a way to lookup snapped inode by file handle. For directory inode, snapped metadata are always stored together with head inode. Client just need to pass vinodeno_t to MDS. For non-directory inode, there can be multiple version of snapped inodes and they can be stored in different dirfrags. Besides vinodeno_t, client also need to tell mds from which dirfrag it got the snapped inode. Another problem of supporting snapshot nfs re-export is that there can be multiple paths to access a snapped inode. For example: mkdir -p d1/d2/d3 mkdir d1/.snap/s1 Paths 'd1/.snap/s1/d2/d3', 'd1/d2/.snap/_s1_<inode number of d1>/d3' and 'd1/d2/d3/.snap/_s1_<inode number of d1>' are all reference to the same snapped inode. For a given snapped inode, There is no convenient way to get the first form and the second form paths. For simplicity, ceph_get_parent() return snapdir for snapped directory inode. Furthermore, client may access snapshot of deleted directory. For example: mkdir -p d1/d2 mkdir d1/.snap/s1 open d1/.snap/s1/d2 rm -rf d1/d2 <nfs server restart> The path constucted by ceph_get_parent() and ceph_get_name() is '<inode of d2>/.snap/_s1_<inode number of d1>'. Futher lookup parent of <inode of d2> will fail. To workaround this case, this patch uses d_obtain_root() to get dentry for snapdir of deleted directory. snapdir dentry has no DCACHE_DISCONNECTED flag set, reconnect_path() stops when it reaches snapdir dentry. Link: http://tracker.ceph.com/issues/22105 Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Yan, Zheng
Ilya Dryomov
parent
0c44a8e0fc
commit
570df4e9c2
2 changed files with 328 additions and 26 deletions
344
fs/ceph/export.c
344
fs/ceph/export.c
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@ -22,18 +22,77 @@ struct ceph_nfs_confh {
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u64 ino, parent_ino;
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} __attribute__ ((packed));
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/*
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* fh for snapped inode
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*/
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struct ceph_nfs_snapfh {
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u64 ino;
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u64 snapid;
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u64 parent_ino;
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u32 hash;
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} __attribute__ ((packed));
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static int ceph_encode_snapfh(struct inode *inode, u32 *rawfh, int *max_len,
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struct inode *parent_inode)
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{
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const static int snap_handle_length =
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sizeof(struct ceph_nfs_snapfh) >> 2;
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struct ceph_nfs_snapfh *sfh = (void *)rawfh;
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u64 snapid = ceph_snap(inode);
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int ret;
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bool no_parent = true;
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if (*max_len < snap_handle_length) {
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*max_len = snap_handle_length;
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ret = FILEID_INVALID;
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goto out;
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}
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ret = -EINVAL;
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if (snapid != CEPH_SNAPDIR) {
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struct inode *dir;
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struct dentry *dentry = d_find_alias(inode);
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if (!dentry)
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goto out;
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rcu_read_lock();
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dir = d_inode_rcu(dentry->d_parent);
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if (ceph_snap(dir) != CEPH_SNAPDIR) {
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sfh->parent_ino = ceph_ino(dir);
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sfh->hash = ceph_dentry_hash(dir, dentry);
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no_parent = false;
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}
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rcu_read_unlock();
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dput(dentry);
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}
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if (no_parent) {
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if (!S_ISDIR(inode->i_mode))
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goto out;
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sfh->parent_ino = sfh->ino;
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sfh->hash = 0;
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}
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sfh->ino = ceph_ino(inode);
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sfh->snapid = snapid;
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*max_len = snap_handle_length;
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ret = FILEID_BTRFS_WITH_PARENT;
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out:
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dout("encode_snapfh %llx.%llx ret=%d\n", ceph_vinop(inode), ret);
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return ret;
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}
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static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
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struct inode *parent_inode)
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{
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const static int handle_length =
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sizeof(struct ceph_nfs_fh) >> 2;
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const static int connected_handle_length =
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sizeof(struct ceph_nfs_confh) >> 2;
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int type;
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struct ceph_nfs_fh *fh = (void *)rawfh;
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struct ceph_nfs_confh *cfh = (void *)rawfh;
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int connected_handle_length = sizeof(*cfh)/4;
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int handle_length = sizeof(*fh)/4;
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/* don't re-export snaps */
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if (ceph_snap(inode) != CEPH_NOSNAP)
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return -EINVAL;
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return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode);
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if (parent_inode && (*max_len < connected_handle_length)) {
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*max_len = connected_handle_length;
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@ -44,6 +103,7 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
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}
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if (parent_inode) {
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struct ceph_nfs_confh *cfh = (void *)rawfh;
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dout("encode_fh %llx with parent %llx\n",
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ceph_ino(inode), ceph_ino(parent_inode));
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cfh->ino = ceph_ino(inode);
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@ -51,6 +111,7 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
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*max_len = connected_handle_length;
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type = FILEID_INO32_GEN_PARENT;
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} else {
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struct ceph_nfs_fh *fh = (void *)rawfh;
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dout("encode_fh %llx\n", ceph_ino(inode));
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fh->ino = ceph_ino(inode);
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*max_len = handle_length;
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@ -59,7 +120,7 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
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return type;
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}
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struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
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static struct inode *__lookup_inode(struct super_block *sb, u64 ino)
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{
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struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
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struct inode *inode;
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@ -81,7 +142,7 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
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mask = CEPH_STAT_CAP_INODE;
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if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
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mask |= CEPH_CAP_XATTR_SHARED;
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req->r_args.getattr.mask = cpu_to_le32(mask);
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req->r_args.lookupino.mask = cpu_to_le32(mask);
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req->r_ino1 = vino;
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req->r_num_caps = 1;
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@ -92,25 +153,113 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
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ceph_mdsc_put_request(req);
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if (!inode)
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return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE);
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}
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return inode;
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}
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struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
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{
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struct inode *inode = __lookup_inode(sb, ino);
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if (IS_ERR(inode))
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return inode;
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if (inode->i_nlink == 0) {
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iput(inode);
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return ERR_PTR(-ESTALE);
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}
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}
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return inode;
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}
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static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
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{
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struct inode *inode = ceph_lookup_inode(sb, ino);
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struct inode *inode = __lookup_inode(sb, ino);
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if (IS_ERR(inode))
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return ERR_CAST(inode);
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if (inode->i_nlink == 0) {
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iput(inode);
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return ERR_PTR(-ESTALE);
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}
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return d_obtain_alias(inode);
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}
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static struct dentry *__snapfh_to_dentry(struct super_block *sb,
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struct ceph_nfs_snapfh *sfh,
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bool want_parent)
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{
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struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
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struct ceph_mds_request *req;
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struct inode *inode;
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struct ceph_vino vino;
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int mask;
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int err;
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bool unlinked = false;
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if (want_parent) {
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vino.ino = sfh->parent_ino;
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if (sfh->snapid == CEPH_SNAPDIR)
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vino.snap = CEPH_NOSNAP;
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else if (sfh->ino == sfh->parent_ino)
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vino.snap = CEPH_SNAPDIR;
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else
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vino.snap = sfh->snapid;
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} else {
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vino.ino = sfh->ino;
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vino.snap = sfh->snapid;
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}
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inode = ceph_find_inode(sb, vino);
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if (inode)
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return d_obtain_alias(inode);
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req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
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USE_ANY_MDS);
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if (IS_ERR(req))
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return ERR_CAST(req);
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mask = CEPH_STAT_CAP_INODE;
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if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
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mask |= CEPH_CAP_XATTR_SHARED;
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req->r_args.lookupino.mask = cpu_to_le32(mask);
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if (vino.snap < CEPH_NOSNAP) {
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req->r_args.lookupino.snapid = cpu_to_le64(vino.snap);
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if (!want_parent && sfh->ino != sfh->parent_ino) {
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req->r_args.lookupino.parent =
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cpu_to_le64(sfh->parent_ino);
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req->r_args.lookupino.hash =
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cpu_to_le32(sfh->hash);
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}
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}
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req->r_ino1 = vino;
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req->r_num_caps = 1;
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err = ceph_mdsc_do_request(mdsc, NULL, req);
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inode = req->r_target_inode;
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if (inode) {
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if (vino.snap == CEPH_SNAPDIR) {
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if (inode->i_nlink == 0)
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unlinked = true;
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inode = ceph_get_snapdir(inode);
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} else if (ceph_snap(inode) == vino.snap) {
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ihold(inode);
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} else {
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/* mds does not support lookup snapped inode */
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err = -EOPNOTSUPP;
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inode = NULL;
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}
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}
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ceph_mdsc_put_request(req);
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if (want_parent) {
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dout("snapfh_to_parent %llx.%llx\n err=%d\n",
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vino.ino, vino.snap, err);
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} else {
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dout("snapfh_to_dentry %llx.%llx parent %llx hash %x err=%d",
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vino.ino, vino.snap, sfh->parent_ino, sfh->hash, err);
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}
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if (!inode)
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return ERR_PTR(-ESTALE);
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/* see comments in ceph_get_parent() */
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return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
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}
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/*
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* convert regular fh to dentry
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*/
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@ -120,6 +269,11 @@ static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
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{
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struct ceph_nfs_fh *fh = (void *)fid->raw;
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if (fh_type == FILEID_BTRFS_WITH_PARENT) {
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struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
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return __snapfh_to_dentry(sb, sfh, false);
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}
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if (fh_type != FILEID_INO32_GEN &&
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fh_type != FILEID_INO32_GEN_PARENT)
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return NULL;
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@ -173,13 +327,49 @@ static struct dentry *__get_parent(struct super_block *sb,
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static struct dentry *ceph_get_parent(struct dentry *child)
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{
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/* don't re-export snaps */
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if (ceph_snap(d_inode(child)) != CEPH_NOSNAP)
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return ERR_PTR(-EINVAL);
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struct inode *inode = d_inode(child);
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struct dentry *dn;
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dout("get_parent %p ino %llx.%llx\n",
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child, ceph_vinop(d_inode(child)));
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return __get_parent(child->d_sb, child, 0);
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if (ceph_snap(inode) != CEPH_NOSNAP) {
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struct inode* dir;
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bool unlinked = false;
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/* do not support non-directory */
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if (!d_is_dir(child)) {
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dn = ERR_PTR(-EINVAL);
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goto out;
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}
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dir = __lookup_inode(inode->i_sb, ceph_ino(inode));
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if (IS_ERR(dir)) {
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dn = ERR_CAST(dir);
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goto out;
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}
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/* There can be multiple paths to access snapped inode.
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* For simplicity, treat snapdir of head inode as parent */
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if (ceph_snap(inode) != CEPH_SNAPDIR) {
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struct inode *snapdir = ceph_get_snapdir(dir);
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if (dir->i_nlink == 0)
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unlinked = true;
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iput(dir);
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if (IS_ERR(snapdir)) {
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dn = ERR_CAST(snapdir);
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goto out;
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}
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dir = snapdir;
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}
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/* If directory has already been deleted, futher get_parent
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* will fail. Do not mark snapdir dentry as disconnected,
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* this prevent exportfs from doing futher get_parent. */
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if (unlinked)
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dn = d_obtain_root(dir);
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else
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dn = d_obtain_alias(dir);
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} else {
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dn = __get_parent(child->d_sb, child, 0);
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}
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out:
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dout("get_parent %p ino %llx.%llx err=%ld\n",
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child, ceph_vinop(inode), (IS_ERR(dn) ? PTR_ERR(dn) : 0));
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return dn;
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}
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/*
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@ -192,6 +382,11 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb,
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struct ceph_nfs_confh *cfh = (void *)fid->raw;
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struct dentry *dentry;
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if (fh_type == FILEID_BTRFS_WITH_PARENT) {
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struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
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return __snapfh_to_dentry(sb, sfh, true);
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}
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if (fh_type != FILEID_INO32_GEN_PARENT)
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return NULL;
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if (fh_len < sizeof(*cfh) / 4)
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@ -204,14 +399,115 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb,
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return dentry;
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}
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static int __get_snap_name(struct dentry *parent, char *name,
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struct dentry *child)
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{
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struct inode *inode = d_inode(child);
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struct inode *dir = d_inode(parent);
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struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
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struct ceph_mds_request *req = NULL;
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char *last_name = NULL;
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unsigned next_offset = 2;
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int err = -EINVAL;
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if (ceph_ino(inode) != ceph_ino(dir))
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goto out;
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if (ceph_snap(inode) == CEPH_SNAPDIR) {
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if (ceph_snap(dir) == CEPH_NOSNAP) {
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strcpy(name, fsc->mount_options->snapdir_name);
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err = 0;
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}
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goto out;
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}
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if (ceph_snap(dir) != CEPH_SNAPDIR)
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goto out;
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while (1) {
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struct ceph_mds_reply_info_parsed *rinfo;
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struct ceph_mds_reply_dir_entry *rde;
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int i;
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req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP,
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USE_AUTH_MDS);
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if (IS_ERR(req)) {
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err = PTR_ERR(req);
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req = NULL;
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goto out;
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}
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err = ceph_alloc_readdir_reply_buffer(req, inode);
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if (err)
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goto out;
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req->r_direct_mode = USE_AUTH_MDS;
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req->r_readdir_offset = next_offset;
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req->r_args.readdir.flags =
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cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
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if (last_name) {
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req->r_path2 = last_name;
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last_name = NULL;
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}
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req->r_inode = dir;
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ihold(dir);
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req->r_dentry = dget(parent);
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inode_lock(dir);
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err = ceph_mdsc_do_request(fsc->mdsc, NULL, req);
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inode_unlock(dir);
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if (err < 0)
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goto out;
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rinfo = &req->r_reply_info;
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for (i = 0; i < rinfo->dir_nr; i++) {
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rde = rinfo->dir_entries + i;
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BUG_ON(!rde->inode.in);
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if (ceph_snap(inode) ==
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le64_to_cpu(rde->inode.in->snapid)) {
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memcpy(name, rde->name, rde->name_len);
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name[rde->name_len] = '\0';
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err = 0;
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goto out;
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}
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}
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if (rinfo->dir_end)
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break;
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BUG_ON(rinfo->dir_nr <= 0);
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rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
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next_offset += rinfo->dir_nr;
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last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
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if (!last_name) {
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err = -ENOMEM;
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goto out;
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}
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ceph_mdsc_put_request(req);
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req = NULL;
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}
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err = -ENOENT;
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out:
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if (req)
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ceph_mdsc_put_request(req);
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kfree(last_name);
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dout("get_snap_name %p ino %llx.%llx err=%d\n",
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child, ceph_vinop(inode), err);
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||||
return err;
|
||||
}
|
||||
|
||||
static int ceph_get_name(struct dentry *parent, char *name,
|
||||
struct dentry *child)
|
||||
{
|
||||
struct ceph_mds_client *mdsc;
|
||||
struct ceph_mds_request *req;
|
||||
struct inode *inode = d_inode(child);
|
||||
int err;
|
||||
|
||||
mdsc = ceph_inode_to_client(d_inode(child))->mdsc;
|
||||
if (ceph_snap(inode) != CEPH_NOSNAP)
|
||||
return __get_snap_name(parent, name, child);
|
||||
|
||||
mdsc = ceph_inode_to_client(inode)->mdsc;
|
||||
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
|
||||
USE_ANY_MDS);
|
||||
if (IS_ERR(req))
|
||||
|
|
@ -219,8 +515,8 @@ static int ceph_get_name(struct dentry *parent, char *name,
|
|||
|
||||
inode_lock(d_inode(parent));
|
||||
|
||||
req->r_inode = d_inode(child);
|
||||
ihold(d_inode(child));
|
||||
req->r_inode = inode;
|
||||
ihold(inode);
|
||||
req->r_ino2 = ceph_vino(d_inode(parent));
|
||||
req->r_parent = d_inode(parent);
|
||||
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
|
||||
|
|
@ -234,10 +530,10 @@ static int ceph_get_name(struct dentry *parent, char *name,
|
|||
memcpy(name, rinfo->dname, rinfo->dname_len);
|
||||
name[rinfo->dname_len] = 0;
|
||||
dout("get_name %p ino %llx.%llx name %s\n",
|
||||
child, ceph_vinop(d_inode(child)), name);
|
||||
child, ceph_vinop(inode), name);
|
||||
} else {
|
||||
dout("get_name %p ino %llx.%llx err %d\n",
|
||||
child, ceph_vinop(d_inode(child)), err);
|
||||
child, ceph_vinop(inode), err);
|
||||
}
|
||||
|
||||
ceph_mdsc_put_request(req);
|
||||
|
|
|
|||
|
|
@ -436,6 +436,12 @@ union ceph_mds_request_args {
|
|||
__le64 length; /* num bytes to lock from start */
|
||||
__u8 wait; /* will caller wait for lock to become available? */
|
||||
} __attribute__ ((packed)) filelock_change;
|
||||
struct {
|
||||
__le32 mask; /* CEPH_CAP_* */
|
||||
__le64 snapid;
|
||||
__le64 parent;
|
||||
__le32 hash;
|
||||
} __attribute__ ((packed)) lookupino;
|
||||
} __attribute__ ((packed));
|
||||
|
||||
#define CEPH_MDS_FLAG_REPLAY 1 /* this is a replayed op */
|
||||
|
|
|
|||
Loading…
Reference in a new issue