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fs/9p: allow disable of xattr support on mount

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xattr creates a lot of additional messages for 9p in
the current implementation.  This allows users to
conditionalize xattr support on 9p mount if they
are on a connection with bad latency.  Using this
flag is also useful when debugging other aspects
of 9p as it reduces the noise in the trace files.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>
This commit is contained in:
Eric Van Hensbergen 2022-12-17 17:19:34 +00:00
parent 740b8bf873
commit 8142db4f27
No known key found for this signature in database
GPG Key ID: 88FFD5FB4A5FFF98
4 changed files with 14 additions and 3 deletions
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2
Documentation/filesystems/9p.rst
View File

@ -137,6 +137,8 @@ Options
This can be used to share devices/named pipes/sockets between
hosts. This functionality will be expanded in later versions.
noxattr do not offer xattr functions on this mount.
access there are four access modes.
user
if a user tries to access a file on v9fs

9
fs/9p/v9fs.c
View File

@ -38,7 +38,7 @@ enum {
/* String options */
Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
/* Options that take no arguments */
Opt_nodevmap,
Opt_nodevmap, Opt_noxattr,
/* Access options */
Opt_access, Opt_posixacl,
/* Lock timeout option */
@ -55,6 +55,7 @@ static const match_table_t tokens = {
{Opt_uname, "uname=%s"},
{Opt_remotename, "aname=%s"},
{Opt_nodevmap, "nodevmap"},
{Opt_noxattr, "noxattr"},
{Opt_cache, "cache=%s"},
{Opt_cachetag, "cachetag=%s"},
{Opt_access, "access=%s"},
@ -149,6 +150,9 @@ int v9fs_show_options(struct seq_file *m, struct dentry *root)
if (v9ses->flags & V9FS_POSIX_ACL)
seq_puts(m, ",posixacl");
if (v9ses->flags & V9FS_NO_XATTR)
seq_puts(m, ",noxattr");
return p9_show_client_options(m, v9ses->clnt);
}
@ -269,6 +273,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
case Opt_nodevmap:
v9ses->nodev = 1;
break;
case Opt_noxattr:
v9ses->flags |= V9FS_NO_XATTR;
break;
case Opt_cachetag:
#ifdef CONFIG_9P_FSCACHE
kfree(v9ses->cachetag);

3
fs/9p/v9fs.h
View File

@ -36,7 +36,8 @@ enum p9_session_flags {
V9FS_ACCESS_SINGLE = 0x04,
V9FS_ACCESS_USER = 0x08,
V9FS_ACCESS_CLIENT = 0x10,
V9FS_POSIX_ACL = 0x20
V9FS_POSIX_ACL = 0x20,
V9FS_NO_XATTR = 0x40
};
/* possible values of ->cache */

3
fs/9p/vfs_super.c
View File

@ -64,7 +64,8 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
sb->s_magic = V9FS_MAGIC;
if (v9fs_proto_dotl(v9ses)) {
sb->s_op = &v9fs_super_ops_dotl;
sb->s_xattr = v9fs_xattr_handlers;
if (!(v9ses->flags & V9FS_NO_XATTR))
sb->s_xattr = v9fs_xattr_handlers;
} else {
sb->s_op = &v9fs_super_ops;
sb->s_time_max = U32_MAX;