On Mon, Oct 15, 2018 at 11:47 PM Luis Henriques <lhenriques@xxxxxxxx> wrote:
>
> 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: Luis Henriques <lhenriques@xxxxxxxx>
> ---
> Documentation/filesystems/ceph.txt | 5 +++++
> fs/ceph/file.c | 3 +++
> fs/ceph/super.c | 13 +++++++++++++
> fs/ceph/super.h | 1 +
> 4 files changed, 22 insertions(+)
>
> diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt
> index 8bf62240e10d..1177052701e1 100644
> --- a/Documentation/filesystems/ceph.txt
> +++ b/Documentation/filesystems/ceph.txt
> @@ -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
> ================
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 0942f45995a1..4af12f5d679f 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -1951,6 +1951,9 @@ 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))
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index eab1359d0553..b5ecd6f50360 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -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)
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 91b13400badd..c005a5400f2e 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -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
>
Looks good to me
Regards
Yan, Zheng
