fs/9p: Rework cache modes and add new options to Documentation

Switch cache modes to a bit-mask and use legacy
cache names as shortcuts.  Update documentation to
include information on both shortcuts and bitmasks.

This patch also fixes missing guards related to fscache.

Update the documentation for new mount flags
and cache modes.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>

1 files changed, 14 insertions, 12 deletions

diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 4b9488cb7a56..f9371b5b70ea 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -287,7 +287,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 		goto out;
 	}
 
-	if ((v9ses->cache >= CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
+	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
 		p9_omode = (p9_omode & !P9_OWRITE) | P9_ORDWR;
 		p9_debug(P9_DEBUG_CACHE,
 			"write-only file with writeback enabled, creating w/ O_RDWR\n");
@@ -325,7 +325,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 		goto out;
 	file->private_data = ofid;
 #ifdef CONFIG_9P_FSCACHE
-	if (v9ses->cache == CACHE_FSCACHE) {
+	if (v9ses->cache & CACHE_FSCACHE) {
 		struct v9fs_inode *v9inode = V9FS_I(inode);
 		fscache_use_cookie(v9fs_inode_cookie(v9inode),
 				   file->f_mode & FMODE_WRITE);
@@ -403,7 +403,7 @@ static int v9fs_vfs_mkdir_dotl(struct mnt_idmap *idmap,
 	}
 
 	/* instantiate inode and assign the unopened fid to the dentry */
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 		if (IS_ERR(inode)) {
 			err = PTR_ERR(inode);
@@ -451,7 +451,7 @@ v9fs_vfs_getattr_dotl(struct mnt_idmap *idmap,
 
 	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 	v9ses = v9fs_dentry2v9ses(dentry);
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 		generic_fillattr(&nop_mnt_idmap, inode, stat);
 		return 0;
 	} else if (v9ses->cache) {
@@ -538,8 +538,7 @@ int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
 {
 	int retval, use_dentry = 0;
 	struct inode *inode = d_inode(dentry);
-	struct v9fs_inode *v9inode = V9FS_I(inode);
-	struct v9fs_session_info *v9ses;
+	struct v9fs_session_info __maybe_unused *v9ses;
 	struct p9_fid *fid = NULL;
 	struct p9_iattr_dotl p9attr = {
 		.uid = INVALID_UID,
@@ -603,8 +602,11 @@ int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
 		truncate_setsize(inode, iattr->ia_size);
 		truncate_pagecache(inode, iattr->ia_size);
 
-		if (v9ses->cache == CACHE_FSCACHE)
-			fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
+#ifdef CONFIG_9P_FSCACHE
+		if (v9ses->cache & CACHE_FSCACHE)
+			fscache_resize_cookie(v9fs_inode_cookie(V9FS_I(inode)),
+				iattr->ia_size);
+#endif
 	}
 
 	v9fs_invalidate_inode_attr(inode);
@@ -732,7 +734,7 @@ v9fs_vfs_symlink_dotl(struct mnt_idmap *idmap, struct inode *dir,
 	}
 
 	v9fs_invalidate_inode_attr(dir);
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 		/* Now walk from the parent so we can get an unopened fid. */
 		fid = p9_client_walk(dfid, 1, &name, 1);
 		if (IS_ERR(fid)) {
@@ -809,7 +811,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
 	}
 
 	v9fs_invalidate_inode_attr(dir);
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 		/* Get the latest stat info from server. */
 		struct p9_fid *fid;
 
@@ -886,7 +888,7 @@ v9fs_vfs_mknod_dotl(struct mnt_idmap *idmap, struct inode *dir,
 	}
 
 	/* instantiate inode and assign the unopened fid to the dentry */
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 		if (IS_ERR(inode)) {
 			err = PTR_ERR(inode);
@@ -971,7 +973,7 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
 	 * We don't want to refresh inode->i_size,
 	 * because we may have cached data
 	 */
-	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
+	flags = (v9ses->cache & CACHE_LOOSE) ?
 		V9FS_STAT2INODE_KEEP_ISIZE : 0;
 	v9fs_stat2inode_dotl(st, inode, flags);
 out: