This commit implements support for the copy_file_range syscall in cephfs.
It is implemented using the RADOS 'copy-from' operation, which allows to
do a remote object copy, without the need to download/upload data from/to
the OSDs.
Some manual copy may however be required if the source/destination file
offsets aren't object aligned or if the copy lenght is smaller than the
object size.
Signed-off-by: Luis Henriques <lhenriques@xxxxxxxx>
---
fs/ceph/file.c | 221 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 221 insertions(+)
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 92ab20433682..7e9ce177bdc3 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
+#include <linux/ceph/striper.h>
#include <linux/module.h>
#include <linux/sched.h>
@@ -1829,6 +1830,225 @@ static long ceph_fallocate(struct file *file, int mode,
return ret;
}
+static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
+ struct file *dst_file, loff_t dst_off,
+ size_t len, unsigned int flags)
+{
+ struct inode *src_inode = file_inode(src_file);
+ struct inode *dst_inode = file_inode(dst_file);
+ struct ceph_inode_info *src_ci = ceph_inode(src_inode);
+ struct ceph_inode_info *dst_ci = ceph_inode(dst_inode);
+ struct ceph_osd_client *osdc =
+ &ceph_inode_to_client(src_inode)->client->osdc;
+ struct ceph_cap_flush *prealloc_cf;
+ struct ceph_object_locator src_oloc, dst_oloc;
+ loff_t endoff = 0;
+ loff_t size;
+ ssize_t ret = -EIO;
+ int src_got = 0;
+ int dst_got = 0;
+ bool retrying = false;
+
+ if (src_inode == dst_inode)
+ return -EINVAL;
+ if (ceph_snap(dst_inode) != CEPH_NOSNAP)
+ return -EROFS;
+
+ prealloc_cf = ceph_alloc_cap_flush();
+ if (!prealloc_cf)
+ return -ENOMEM;
+
+ /* Start by sync'ing the source file */
+ ret = file_write_and_wait_range(src_file, src_off, (src_off + len));
+ if (ret < 0)
+ goto out;
+
+retry_caps:
+ ret = ceph_get_caps(dst_ci, CEPH_CAP_FILE_WR, CEPH_CAP_FILE_BUFFER,
+ endoff, &dst_got, NULL);
+ if (ret < 0)
+ goto out;
+ /*
+ * We also need to get FILE_RD capabilities for source file as other
+ * clients may have dirty data in their caches. And OSDs know nothing
+ * about caps, so they can't safely do the remote object copies.
+ *
+ * However, since we're already holding the FILE_WR capability for the
+ * source file, we would risk a deadlock by using ceph_get_caps. Thus,
+ * we'll do some retry dance instead to try to get both capabilities.
+ * If everything fails, we just return -EOPNOTSUPP and fallback to the
+ * VFS default copy_file_range implementation.
+ */
+ ret = ceph_try_get_caps(src_ci, CEPH_CAP_FILE_RD, CEPH_CAP_FILE_SHARED,
+ false, &src_got);
+ if (ret <= 0) {
+ if (retrying) {
+ ret = -EOPNOTSUPP;
+ goto out_dst_caps;
+ }
+ /* Start by dropping dsc_ci caps and getting src_ci caps */
+ ceph_put_cap_refs(dst_ci, dst_got);
+ ret = ceph_get_caps(src_ci, CEPH_CAP_FILE_RD,
+ CEPH_CAP_FILE_SHARED,
+ (src_off + len), &src_got, NULL);
+ if (ret < 0) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ /*... drop them too, and retry */
+ ceph_put_cap_refs(src_ci, src_got);
+ retrying = true;
+ goto retry_caps;
+ }
+
+ size = i_size_read(src_inode);
+ /*
+ * Don't copy beyond source file EOF. Instead of simply setting lenght
+ * to (size - src_off), just drop to VFS default implementation, as the
+ * local i_size may be stale due to other clients writing to the source
+ * inode.
+ */
+ if (src_off + len > size) {
+ ret = -EOPNOTSUPP;
+ goto out_caps;
+ }
+ size = i_size_read(dst_inode);
+ endoff = dst_off + len;
+ ret = inode_newsize_ok(dst_inode, endoff);
+ if (ret)
+ goto out_caps;
+
+ if (ceph_quota_is_max_bytes_exceeded(dst_inode, endoff)) {
+ ret = -EDQUOT;
+ goto out_caps;
+ }
+
+ /* Drop dst file cached pages */
+ ret = invalidate_inode_pages2_range(dst_inode->i_mapping,
+ dst_off >> PAGE_SHIFT,
+ endoff >> PAGE_SHIFT);
+ if (ret < 0) {
+ printk("Failed to invalidate inode pages (%ld)\n", ret);
+ ret = 0; /* XXX */
+ }
+ src_oloc.pool = src_ci->i_layout.pool_id;
+ src_oloc.pool_ns = ceph_try_get_string(src_ci->i_layout.pool_ns);
+ dst_oloc.pool = dst_ci->i_layout.pool_id;
+ dst_oloc.pool_ns = ceph_try_get_string(dst_ci->i_layout.pool_ns);
+ /*
+ * TODO: should file_start_write/file_end_write be used for the whole
+ * loop? Or any other locking?
+ */
+ while (len > 0) {
+ struct ceph_object_id src_oid, dst_oid;
+ u64 objnum, objoff;
+ u32 objlen;
+ size_t copy_len = min_t(size_t, src_ci->i_layout.object_size, len);
+ int err = 0;
+
+ ceph_calc_file_object_mapping(&src_ci->i_layout, src_off,
+ copy_len, &objnum, &objoff,
+ &objlen);
+ ceph_oid_init(&src_oid);
+ ceph_oid_printf(&src_oid, "%llx.%08llx",
+ src_ci->i_vino.ino, objnum);
+
+ /* Do manual copy if:
+ * - source file offset isn't object aligned, or
+ * - copy length is smaller than object size
+ */
+ if (objoff || (copy_len < src_ci->i_layout.object_size)) {
+ /* Do not copy beyond this object */
+ if (copy_len > objlen)
+ copy_len = objlen;
+ err = do_splice_direct(src_file, &src_off, dst_file,
+ &dst_off, copy_len, flags);
+ if (err < 0) {
+ ret = err;
+ goto out_caps;
+ }
+ len -= copy_len;
+ ret += copy_len;
+ continue;
+ }
+
+ ceph_calc_file_object_mapping(&dst_ci->i_layout, dst_off,
+ copy_len, &objnum, &objoff,
+ &objlen);
+ ceph_oid_init(&dst_oid);
+ ceph_oid_printf(&dst_oid, "%llx.%08llx",
+ dst_ci->i_vino.ino, objnum);
+ /* Again... do a manual copy if:
+ * - destination file offset isn't object aligned, or
+ * - copy length is smaller than object size
+ * (although the object size should be the same for different
+ * files in the same filesystem...)
+ */
+ if (objoff || (copy_len < dst_ci->i_layout.object_size)) {
+ if (copy_len > objlen)
+ copy_len = objlen;
+ err = do_splice_direct(src_file, &src_off, dst_file,
+ &dst_off, copy_len, flags);
+ if (err < 0) {
+ ret = err;
+ goto out_caps;
+ }
+ len -= copy_len;
+ ceph_oid_destroy(&src_oid);
+ ret += copy_len;
+ continue;
+ }
+ /* Finally... do an object remote copy */
+ err = ceph_osdc_copy_from(osdc, src_ci->i_vino.snap,
+ 0, /* XXX src_ci->i_version ? */
+ &src_oid, &src_oloc,
+ CEPH_OSD_OP_FLAG_FADVISE_SEQUENTIAL|CEPH_OSD_OP_FLAG_FADVISE_WILLNEED,
+ dst_ci->i_vino.snap, &dst_oid,
+ &dst_oloc,
+ CEPH_OSD_OP_FLAG_FADVISE_SEQUENTIAL|CEPH_OSD_OP_FLAG_FADVISE_WILLNEED);
+ if (err) {
+ printk("copy_from returned an error: %d\n", err); /* XXX */
+ ret = err;
+ goto out_caps;
+ }
+ len -= copy_len;
+ src_off += copy_len;
+ dst_off += copy_len;
+ ret += copy_len;
+ ceph_oid_destroy(&src_oid);
+ ceph_oid_destroy(&dst_oid);
+ }
+ /* Let the MDS know about destination object size change */
+ if (endoff > size) {
+ int dirty;
+ int caps_flags = CHECK_CAPS_AUTHONLY;
+
+ if (ceph_quota_is_max_bytes_approaching(dst_inode, endoff))
+ caps_flags |= CHECK_CAPS_NODELAY;
+ if (ceph_inode_set_size(dst_inode, endoff))
+ caps_flags |= CHECK_CAPS_AUTHONLY;
+ if (caps_flags)
+ ceph_check_caps(dst_ci, caps_flags, NULL);
+ spin_lock(&dst_ci->i_ceph_lock);
+ dst_ci->i_inline_version = CEPH_INLINE_NONE;
+ dirty = __ceph_mark_dirty_caps(
+ dst_ci,
+ CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER,
+ &prealloc_cf);
+ spin_unlock(&dst_ci->i_ceph_lock);
+ if (dirty)
+ __mark_inode_dirty(dst_inode, dirty);
+ }
+out_caps:
+ ceph_put_cap_refs(src_ci, src_got);
+out_dst_caps:
+ ceph_put_cap_refs(dst_ci, dst_got);
+out:
+ ceph_free_cap_flush(prealloc_cf);
+
+ return ret;
+}
+
const struct file_operations ceph_file_fops = {
.open = ceph_open,
.release = ceph_release,
@@ -1844,5 +2064,6 @@ const struct file_operations ceph_file_fops = {
.unlocked_ioctl = ceph_ioctl,
.compat_ioctl = ceph_ioctl,
.fallocate = ceph_fallocate,
+ .copy_file_range = ceph_copy_file_range,
};
