By this point we have two ways to test for inode reuse - qid and qid+path.
By default, uncached mode uses qid+path and cached mode uses qid (and in
fact does not support qid+path). This patch adds the option to control
the behaviour for uncached mode.
In a future version, if we can negotiate with the server and be sure that
it won't give us duplicate qid.path, the default for those cases can be
qid-based.
Signed-off-by: Tingmao Wang <m@xxxxxxxxxx>
Cc: "Mickaël Salaün" <mic@xxxxxxxxxxx>
Cc: "Günther Noack" <gnoack@xxxxxxxxxx>
---
Changes since v1:
- Removed inodeident=none and instead supports inodeident=qid. This means
that there is no longer an option to not re-use inodes at all.
- No longer supports inodeident=path on cached mode, checks added at
option init time.
- Added explicit bits for both V9FS_INODE_IDENT_PATH and
V9FS_INODE_IDENT_QID, in order to set a default based on cache bits when
neither are set explicitly by the user.
fs/9p/v9fs.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++-
fs/9p/v9fs.h | 3 +++
2 files changed, 61 insertions(+), 1 deletion(-)
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 77e9c4387c1d..f87d6680b85a 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -36,7 +36,7 @@ enum {
/* Options that take integer arguments */
Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
/* String options */
- Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
+ Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag, Opt_inodeident,
/* Options that take no arguments */
Opt_nodevmap, Opt_noxattr, Opt_directio, Opt_ignoreqv,
/* Access options */
@@ -63,6 +63,7 @@ static const match_table_t tokens = {
{Opt_access, "access=%s"},
{Opt_posixacl, "posixacl"},
{Opt_locktimeout, "locktimeout=%u"},
+ {Opt_inodeident, "inodeident=%s"},
{Opt_err, NULL}
};
@@ -149,6 +150,21 @@ int v9fs_show_options(struct seq_file *m, struct dentry *root)
if (v9ses->flags & V9FS_NO_XATTR)
seq_puts(m, ",noxattr");
+ switch (v9ses->flags & V9FS_INODE_IDENT_MASK) {
+ case V9FS_INODE_IDENT_QID:
+ seq_puts(m, ",inodeident=qid");
+ break;
+ case V9FS_INODE_IDENT_PATH:
+ seq_puts(m, ",inodeident=path");
+ break;
+ default:
+ /*
+ * Unspecified, will be set later in v9fs_session_init depending on
+ * cache setting
+ */
+ break;
+ }
+
return p9_show_client_options(m, v9ses->clnt);
}
@@ -369,6 +385,26 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
v9ses->session_lock_timeout = (long)option * HZ;
break;
+ case Opt_inodeident:
+ s = match_strdup(&args[0]);
+ if (!s) {
+ ret = -ENOMEM;
+ p9_debug(P9_DEBUG_ERROR,
+ "problem allocating copy of inodeident arg\n");
+ goto free_and_return;
+ }
+ v9ses->flags &= ~V9FS_INODE_IDENT_MASK;
+ if (strcmp(s, "qid") == 0) {
+ v9ses->flags |= V9FS_INODE_IDENT_QID;
+ } else if (strcmp(s, "path") == 0) {
+ v9ses->flags |= V9FS_INODE_IDENT_PATH;
+ } else {
+ ret = -EINVAL;
+ p9_debug(P9_DEBUG_ERROR, "Unknown inodeident argument %s\n", s);
+ }
+ kfree(s);
+ break;
+
default:
continue;
}
@@ -393,6 +429,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
{
struct p9_fid *fid;
int rc = -ENOMEM;
+ bool cached;
v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
if (!v9ses->uname)
@@ -427,6 +464,26 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
if (rc < 0)
goto err_clnt;
+ cached = v9ses->cache & (CACHE_META | CACHE_LOOSE);
+
+ if (cached && v9ses->flags & V9FS_INODE_IDENT_PATH) {
+ rc = -EINVAL;
+ p9_debug(P9_DEBUG_ERROR,
+ "inodeident=path not supported in cached mode\n");
+ goto err_clnt;
+ }
+
+ if (!(v9ses->flags & V9FS_INODE_IDENT_MASK)) {
+ /* Unspecified - use default */
+ if (cached) {
+ /* which is qid in cached mode (path not supported) */
+ v9ses->flags |= V9FS_INODE_IDENT_QID;
+ } else {
+ /* ...or path in uncached mode */
+ v9ses->flags |= V9FS_INODE_IDENT_PATH;
+ }
+ }
+
v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
if (!v9fs_proto_dotl(v9ses) &&
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 134b55a605be..b4e738c1bba5 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -43,8 +43,11 @@ enum p9_session_flags {
V9FS_DIRECT_IO = 0x100,
V9FS_SYNC = 0x200,
V9FS_INODE_IDENT_PATH = 0x400,
+ V9FS_INODE_IDENT_QID = 0x800,
};
+#define V9FS_INODE_IDENT_MASK (V9FS_INODE_IDENT_PATH | V9FS_INODE_IDENT_QID)
+
/**
* enum p9_cache_shortcuts - human readable cache preferences
* @CACHE_SC_NONE: disable all caches
--
2.51.0
