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![Luis Henriques](/assets/img/avatar_default.png)
Similarly to commit 03f219041f
("ceph: check i_nlink while converting
a file handle to dentry"), this fixes another corner case with
name_to_handle_at/open_by_handle_at. The issue has been detected by
xfstest generic/467, when doing:
- name_to_handle_at("/cephfs/myfile")
- open("/cephfs/myfile")
- unlink("/cephfs/myfile")
- sync; sync;
- drop caches
- open_by_handle_at()
The call to open_by_handle_at should not fail because the file hasn't been
deleted yet (only unlinked) and we do have a valid handle to it. -ESTALE
shall be returned only if i_nlink is 0 *and* i_count is 1.
This patch also makes sure we have LINK caps before checking i_nlink.
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
561 lines
13 KiB
C
561 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/ceph/ceph_debug.h>
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#include <linux/exportfs.h>
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#include <linux/slab.h>
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#include <asm/unaligned.h>
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#include "super.h"
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#include "mds_client.h"
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/*
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* Basic fh
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*/
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struct ceph_nfs_fh {
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u64 ino;
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} __attribute__ ((packed));
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/*
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* Larger fh that includes parent ino.
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*/
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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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static const 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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static const int handle_length =
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sizeof(struct ceph_nfs_fh) >> 2;
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static const int connected_handle_length =
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sizeof(struct ceph_nfs_confh) >> 2;
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int type;
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if (ceph_snap(inode) != CEPH_NOSNAP)
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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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return FILEID_INVALID;
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} else if (*max_len < handle_length) {
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*max_len = handle_length;
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return FILEID_INVALID;
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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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cfh->parent_ino = ceph_ino(parent_inode);
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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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type = FILEID_INO32_GEN;
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}
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return type;
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}
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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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struct ceph_vino vino;
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int err;
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vino.ino = ino;
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vino.snap = CEPH_NOSNAP;
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inode = ceph_find_inode(sb, vino);
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if (!inode) {
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struct ceph_mds_request *req;
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int mask;
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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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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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ihold(inode);
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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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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 = __lookup_inode(sb, ino);
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int err;
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if (IS_ERR(inode))
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return ERR_CAST(inode);
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/* We need LINK caps to reliably check i_nlink */
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err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false);
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if (err)
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return ERR_PTR(err);
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/* -ESTALE if inode as been unlinked and no file is open */
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if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) {
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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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static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
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struct fid *fid,
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int fh_len, int fh_type)
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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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if (fh_len < sizeof(*fh) / 4)
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return NULL;
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dout("fh_to_dentry %llx\n", fh->ino);
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return __fh_to_dentry(sb, fh->ino);
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}
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static struct dentry *__get_parent(struct super_block *sb,
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struct dentry *child, 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 ceph_mds_request *req;
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struct inode *inode;
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int mask;
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int err;
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req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
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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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if (child) {
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req->r_inode = d_inode(child);
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ihold(d_inode(child));
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} else {
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req->r_ino1 = (struct ceph_vino) {
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.ino = ino,
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.snap = CEPH_NOSNAP,
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};
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}
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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_num_caps = 1;
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err = ceph_mdsc_do_request(mdsc, NULL, req);
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if (err) {
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ceph_mdsc_put_request(req);
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return ERR_PTR(err);
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}
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inode = req->r_target_inode;
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if (inode)
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ihold(inode);
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ceph_mdsc_put_request(req);
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if (!inode)
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return ERR_PTR(-ENOENT);
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return d_obtain_alias(inode);
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}
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static struct dentry *ceph_get_parent(struct dentry *child)
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{
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struct inode *inode = d_inode(child);
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struct dentry *dn;
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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), (long)PTR_ERR_OR_ZERO(dn));
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return dn;
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}
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/*
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* convert regular fh to parent
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*/
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static struct dentry *ceph_fh_to_parent(struct super_block *sb,
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struct fid *fid,
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int fh_len, int fh_type)
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{
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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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return NULL;
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dout("fh_to_parent %llx\n", cfh->parent_ino);
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dentry = __get_parent(sb, NULL, cfh->ino);
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if (unlikely(dentry == ERR_PTR(-ENOENT)))
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dentry = __fh_to_dentry(sb, cfh->parent_ino);
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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);
|
|
if (ceph_snap(inode) ==
|
|
le64_to_cpu(rde->inode.in->snapid)) {
|
|
memcpy(name, rde->name, rde->name_len);
|
|
name[rde->name_len] = '\0';
|
|
err = 0;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (rinfo->dir_end)
|
|
break;
|
|
|
|
BUG_ON(rinfo->dir_nr <= 0);
|
|
rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
|
|
next_offset += rinfo->dir_nr;
|
|
last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
|
|
if (!last_name) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ceph_mdsc_put_request(req);
|
|
req = NULL;
|
|
}
|
|
err = -ENOENT;
|
|
out:
|
|
if (req)
|
|
ceph_mdsc_put_request(req);
|
|
kfree(last_name);
|
|
dout("get_snap_name %p ino %llx.%llx err=%d\n",
|
|
child, ceph_vinop(inode), err);
|
|
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;
|
|
|
|
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))
|
|
return PTR_ERR(req);
|
|
|
|
inode_lock(d_inode(parent));
|
|
|
|
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);
|
|
req->r_num_caps = 2;
|
|
err = ceph_mdsc_do_request(mdsc, NULL, req);
|
|
|
|
inode_unlock(d_inode(parent));
|
|
|
|
if (!err) {
|
|
struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
|
|
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(inode), name);
|
|
} else {
|
|
dout("get_name %p ino %llx.%llx err %d\n",
|
|
child, ceph_vinop(inode), err);
|
|
}
|
|
|
|
ceph_mdsc_put_request(req);
|
|
return err;
|
|
}
|
|
|
|
const struct export_operations ceph_export_ops = {
|
|
.encode_fh = ceph_encode_fh,
|
|
.fh_to_dentry = ceph_fh_to_dentry,
|
|
.fh_to_parent = ceph_fh_to_parent,
|
|
.get_parent = ceph_get_parent,
|
|
.get_name = ceph_get_name,
|
|
};
|