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| author | Jeff Layton <jlayton@kernel.org> | 2021-11-30 20:12:13 +0100 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2022-01-13 13:40:07 +0100 |
| commit | 94cc0877cad0bc6ca84686c4fa874bf530eb8b88 (patch) | |
| tree | f0b81d20b964a613d91b0453d8a085615fd298bd /fs/ceph/super.c | |
| parent | ceph: don't check for quotas on MDS stray dirs (diff) | |
| download | linux-94cc0877cad0bc6ca84686c4fa874bf530eb8b88.tar.xz linux-94cc0877cad0bc6ca84686c4fa874bf530eb8b88.zip | |
ceph: add new "nopagecache" option
CephFS is a bit unlike most other filesystems in that it only
conditionally does buffered I/O based on the caps that it gets from the
MDS. In most cases, unless there is contended access for an inode the
MDS does give Fbc caps to the client, so the unbuffered codepaths are
only infrequently traveled and are difficult to test.
At one time, the "-o sync" mount option would give you this behavior,
but that was removed in commit 7ab9b3807097 ("ceph: Don't use
ceph-sync-mode for synchronous-fs.").
Add a new mount option to tell the client to ignore Fbc caps when doing
I/O, and to use the synchronous codepaths exclusively, even on
non-O_DIRECT file descriptors. We already have an ioctl that forces this
behavior on a per-file basis, so we can just always set the CEPH_F_SYNC
flag in the file description on such mounts.
Additionally, this patch also changes the client to not request Fbc when
doing direct I/O. We aren't using the cache with O_DIRECT so we don't
have any need for those caps.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Greg Farnum <gfarnum@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/super.c')
| -rw-r--r-- | fs/ceph/super.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 2166fc2c1625..eb255d24e321 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -160,6 +160,7 @@ enum { Opt_quotadf, Opt_copyfrom, Opt_wsync, + Opt_pagecache, }; enum ceph_recover_session_mode { @@ -201,6 +202,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = { fsparam_string ("mon_addr", Opt_mon_addr), fsparam_u32 ("wsize", Opt_wsize), fsparam_flag_no ("wsync", Opt_wsync), + fsparam_flag_no ("pagecache", Opt_pagecache), {} }; @@ -564,6 +566,12 @@ static int ceph_parse_mount_param(struct fs_context *fc, else fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS; break; + case Opt_pagecache: + if (result.negated) + fsopt->flags |= CEPH_MOUNT_OPT_NOPAGECACHE; + else + fsopt->flags &= ~CEPH_MOUNT_OPT_NOPAGECACHE; + break; default: BUG(); } @@ -699,6 +707,9 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root) if (!(fsopt->flags & CEPH_MOUNT_OPT_ASYNC_DIROPS)) seq_puts(m, ",wsync"); + if (fsopt->flags & CEPH_MOUNT_OPT_NOPAGECACHE) + seq_puts(m, ",nopagecache"); + if (fsopt->wsize != CEPH_MAX_WRITE_SIZE) seq_printf(m, ",wsize=%u", fsopt->wsize); if (fsopt->rsize != CEPH_MAX_READ_SIZE) |