Commit ea4cdc54 authored by Luis Henriques's avatar Luis Henriques Committed by Ilya Dryomov
Browse files

ceph: new mount option to disable usage of copy-from op 



Add a new mount option 'nocopyfrom' that will prevent the usage of the
RADOS 'copy-from' operation in cephfs.  This could be useful, for example,
for an administrator to temporarily mitigate any possible bugs in the
'copy-from' implementation.

Currently, only copy_file_range uses this RADOS operation.  Setting this
mount option will result in this syscall reverting to the default VFS
implementation, i.e. to perform the copies locally instead of doing remote
object copies.

Signed-off-by: default avatarLuis Henriques <lhenriques@suse.com>
Reviewed-by: default avatar"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 503f82a9

Documentation/filesystems/ceph.txt

+5 −0
Original line number Diff line number Diff line
@@ -151,6 +151,11 @@ Mount Options 
        Report overall filesystem usage in statfs instead of using the root

        directory quota.



  nocopyfrom

        Don't use the RADOS 'copy-from' operation to perform remote object

        copies.  Currently, it's only used in copy_file_range, which will revert

        to the default VFS implementation if this option is used.



More Information

================

fs/ceph/file.c

+3 −0
Original line number Diff line number Diff line
@@ -1917,6 +1917,9 @@ 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))

		return -EOPNOTSUPP;



	if ((src_ci->i_layout.stripe_unit != dst_ci->i_layout.stripe_unit) ||

	    (src_ci->i_layout.stripe_count != dst_ci->i_layout.stripe_count) ||

	    (src_ci->i_layout.object_size != dst_ci->i_layout.object_size))

fs/ceph/super.c

+13 −0
Original line number Diff line number Diff line
@@ -165,6 +165,8 @@ enum { 
	Opt_noacl,

	Opt_quotadf,

	Opt_noquotadf,

	Opt_copyfrom,

	Opt_nocopyfrom,

};



static match_table_t fsopt_tokens = {
@@ -203,6 +205,8 @@ static match_table_t fsopt_tokens = { 
	{Opt_noacl, "noacl"},

	{Opt_quotadf, "quotadf"},

	{Opt_noquotadf, "noquotadf"},

	{Opt_copyfrom, "copyfrom"},

	{Opt_nocopyfrom, "nocopyfrom"},

	{-1, NULL}

};
@@ -355,6 +359,12 @@ static int parse_fsopt_token(char *c, void *private) 
	case Opt_noquotadf:

		fsopt->flags |= CEPH_MOUNT_OPT_NOQUOTADF;

		break;

	case Opt_copyfrom:

		fsopt->flags &= ~CEPH_MOUNT_OPT_NOCOPYFROM;

		break;

	case Opt_nocopyfrom:

		fsopt->flags |= CEPH_MOUNT_OPT_NOCOPYFROM;

		break;

#ifdef CONFIG_CEPH_FS_POSIX_ACL

	case Opt_acl:

		fsopt->sb_flags |= SB_POSIXACL;
@@ -553,6 +563,9 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root) 
		seq_puts(m, ",noacl");

#endif



	if (fsopt->flags & CEPH_MOUNT_OPT_NOCOPYFROM)

		seq_puts(m, ",nocopyfrom");



	if (fsopt->mds_namespace)

		seq_show_option(m, "mds_namespace", fsopt->mds_namespace);

	if (fsopt->wsize != CEPH_MAX_WRITE_SIZE)

fs/ceph/super.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#define CEPH_MOUNT_OPT_NOPOOLPERM      (1<<11) /* no pool permission check */

#define CEPH_MOUNT_OPT_MOUNTWAIT       (1<<12) /* mount waits if no mds is up */

#define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */

#define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */



#define CEPH_MOUNT_OPT_DEFAULT    CEPH_MOUNT_OPT_DCACHE

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