84 lines
3.1 KiB
Diff
84 lines
3.1 KiB
Diff
|
From be7f19b21c84004c5a0705f040b957fd1c609e2e Mon Sep 17 00:00:00 2001
|
||
|
|
From: =?UTF-8?q?Etienne=20Dubl=C3=A9?= <etienne.duble@imag.fr>
|
||
|
|
Date: Sun, 20 Sep 2020 20:08:15 +0200
|
||
|
|
Subject: [PATCH 3/4] Allow caching symlinks in kernel page cache. (#551)
|
||
|
|
|
||
|
|
This commit defines a new capability called `FUSE_CAP_CACHE_SYMLINKS`.
|
||
|
|
It is off by default but you can now enable it by setting this flag in
|
||
|
|
in the `want` field of the `fuse_conn_info` structure.
|
||
|
|
|
||
|
|
When enabled, the kernel will save symlinks in its page cache,
|
||
|
|
by making use of the feature introduced in kernel 4.20:
|
||
|
|
https://github.com/torvalds/linux/commit/5571f1e65486be025f73fa6aa30fb03725d362a2
|
||
|
|
|
||
|
|
(cherry picked from commit ba3b225a126ebb3c6d4fe27c9f7c73aa4167001e)
|
||
|
|
Signed-off-by: Pavel Reichl <preichl@redhat.com>
|
||
|
|
---
|
||
|
|
example/printcap.c | 2 ++
|
||
|
|
include/fuse_common.h | 13 +++++++++++++
|
||
|
|
lib/fuse_lowlevel.c | 4 ++++
|
||
|
|
3 files changed, 19 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/example/printcap.c b/example/printcap.c
|
||
|
|
index 77dea14..a66036f 100644
|
||
|
|
--- a/example/printcap.c
|
||
|
|
+++ b/example/printcap.c
|
||
|
|
@@ -77,6 +77,8 @@ static void pc_init(void *userdata,
|
||
|
|
printf("\tFUSE_CAP_PARALLEL_DIROPS\n");
|
||
|
|
if(conn->capable & FUSE_CAP_POSIX_ACL)
|
||
|
|
printf("\tFUSE_CAP_POSIX_ACL\n");
|
||
|
|
+ if(conn->capable & FUSE_CAP_CACHE_SYMLINKS)
|
||
|
|
+ printf("\tFUSE_CAP_CACHE_SYMLINKS\n");
|
||
|
|
fuse_session_exit(se);
|
||
|
|
}
|
||
|
|
|
||
|
|
diff --git a/include/fuse_common.h b/include/fuse_common.h
|
||
|
|
index 83c9dee..a5a0ea5 100644
|
||
|
|
--- a/include/fuse_common.h
|
||
|
|
+++ b/include/fuse_common.h
|
||
|
|
@@ -316,6 +316,19 @@ struct fuse_loop_config {
|
||
|
|
*/
|
||
|
|
#define FUSE_CAP_HANDLE_KILLPRIV (1 << 20)
|
||
|
|
|
||
|
|
+/**
|
||
|
|
+ * Indicates that the kernel supports caching symlinks in its page cache.
|
||
|
|
+ *
|
||
|
|
+ * When this feature is enabled, symlink targets are saved in the page cache.
|
||
|
|
+ * You can invalidate a cached link by calling:
|
||
|
|
+ * `fuse_lowlevel_notify_inval_inode(se, ino, 0, 0);`
|
||
|
|
+ *
|
||
|
|
+ * This feature is disabled by default.
|
||
|
|
+ * If the kernel supports it (>= 4.20), you can enable this feature by
|
||
|
|
+ * setting this flag in the `want` field of the `fuse_conn_info` structure.
|
||
|
|
+ */
|
||
|
|
+#define FUSE_CAP_CACHE_SYMLINKS (1 << 23)
|
||
|
|
+
|
||
|
|
/**
|
||
|
|
* Ioctl flags
|
||
|
|
*
|
||
|
|
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
|
||
|
|
index 60195e0..43f785f 100644
|
||
|
|
--- a/lib/fuse_lowlevel.c
|
||
|
|
+++ b/lib/fuse_lowlevel.c
|
||
|
|
@@ -1882,6 +1882,8 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
|
||
|
|
se->conn.capable |= FUSE_CAP_POSIX_ACL;
|
||
|
|
if (arg->flags & FUSE_HANDLE_KILLPRIV)
|
||
|
|
se->conn.capable |= FUSE_CAP_HANDLE_KILLPRIV;
|
||
|
|
+ if (arg->flags & FUSE_CACHE_SYMLINKS)
|
||
|
|
+ se->conn.capable |= FUSE_CAP_CACHE_SYMLINKS;
|
||
|
|
if (!(arg->flags & FUSE_MAX_PAGES)) {
|
||
|
|
size_t max_bufsize =
|
||
|
|
FUSE_DEFAULT_MAX_PAGES_PER_REQ * getpagesize()
|
||
|
|
@@ -2002,6 +2004,8 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
|
||
|
|
outarg.flags |= FUSE_WRITEBACK_CACHE;
|
||
|
|
if (se->conn.want & FUSE_CAP_POSIX_ACL)
|
||
|
|
outarg.flags |= FUSE_POSIX_ACL;
|
||
|
|
+ if (se->conn.want & FUSE_CAP_CACHE_SYMLINKS)
|
||
|
|
+ outarg.flags |= FUSE_CACHE_SYMLINKS;
|
||
|
|
outarg.max_readahead = se->conn.max_readahead;
|
||
|
|
outarg.max_write = se->conn.max_write;
|
||
|
|
if (se->conn.proto_minor >= 13) {
|
||
|
|
--
|
||
|
|
2.36.1
|
||
|
|
|