[PATCH v2] ceph: allow object copies across different filesystems in the same cluster

[Luis Henriques]

OSDs are able to perform object copies across different pools.  Thus,
there's no need to prevent copy_file_range from doing remote copies if the
source and destination superblocks are different.  Only return -EXDEV if
they have different fsid (the cluster ID).

Signed-off-by: Luis Henriques <lhenriq...@suse.com>
---
 fs/ceph/file.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

Hi,

Here's the patch changelog since initial submittion:

- Dropped have_fsid checks on client structs
- Use %pU to print the fsid instead of raw hex strings (%*ph)
- Fixed 'To:' field in email so that this time the patch hits vger

Cheers,
--
Luis

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 685a03cc4b77..4a624a1dd0bb 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1904,6 +1904,7 @@ static ssize_t __ceph_copy_file_range(struct file 
*src_file, loff_t src_off,
        struct ceph_inode_info *src_ci = ceph_inode(src_inode);
        struct ceph_inode_info *dst_ci = ceph_inode(dst_inode);
        struct ceph_cap_flush *prealloc_cf;
+       struct ceph_fs_client *src_fsc = ceph_inode_to_client(src_inode);
        struct ceph_object_locator src_oloc, dst_oloc;
        struct ceph_object_id src_oid, dst_oid;
        loff_t endoff = 0, size;
@@ -1915,8 +1916,17 @@ static ssize_t __ceph_copy_file_range(struct file 
*src_file, loff_t src_off,
 
        if (src_inode == dst_inode)
                return -EINVAL;
-       if (src_inode->i_sb != dst_inode->i_sb)
-               return -EXDEV;
+       if (src_inode->i_sb != dst_inode->i_sb) {
+               struct ceph_fs_client *dst_fsc = 
ceph_inode_to_client(dst_inode);
+
+               if (ceph_fsid_compare(&src_fsc->client->fsid,
+                                     &dst_fsc->client->fsid)) {
+                       dout("Copying object across different clusters:");
+                       dout("  src fsid: %pU dst fsid: %pU\n",
+                            &src_fsc->client->fsid, &dst_fsc->client->fsid);
+                       return -EXDEV;
+               }
+       }
        if (ceph_snap(dst_inode) != CEPH_NOSNAP)
                return -EROFS;
 
@@ -1928,7 +1938,7 @@ static ssize_t __ceph_copy_file_range(struct file 
*src_file, loff_t src_off,
         * efficient).
         */
 
-       if (ceph_test_mount_opt(ceph_inode_to_client(src_inode), NOCOPYFROM))
+       if (ceph_test_mount_opt(src_fsc, NOCOPYFROM))
                return -EOPNOTSUPP;
 
        if ((src_ci->i_layout.stripe_unit != dst_ci->i_layout.stripe_unit) ||
@@ -2044,7 +2054,7 @@ static ssize_t __ceph_copy_file_range(struct file 
*src_file, loff_t src_off,
                                dst_ci->i_vino.ino, dst_objnum);
                /* Do an object remote copy */
                err = ceph_osdc_copy_from(
-                       &ceph_inode_to_client(src_inode)->client->osdc,
+                       &src_fsc->client->osdc,
                        src_ci->i_vino.snap, 0,
                        &src_oid, &src_oloc,
                        CEPH_OSD_OP_FLAG_FADVISE_SEQUENTIAL |