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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-18 09:23:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-18 09:23:03 -0700
commit9eead2a8115d2a6aecf267c292f751f7761fa5f8 (patch)
tree133cc2c9616bbc53b92fdf68137621a11e3c80c6 /fs/fuse/inode.c
parent6f130478e24d810078c3f0ee292bcc4ec034dcce (diff)
parent79a9d99434b104c562f30f21b75317667f444793 (diff)
downloadop-kernel-dev-9eead2a8115d2a6aecf267c292f751f7761fa5f8.zip
op-kernel-dev-9eead2a8115d2a6aecf267c292f751f7761fa5f8.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: add fusectl interface to max_background fuse: limit user-specified values of max background requests fuse: use drop_nlink() instead of direct nlink manipulation fuse: document protocol version negotiation fuse: make the number of max background requests and congestion threshold tunable
Diffstat (limited to 'fs/fuse/inode.c')
-rw-r--r--fs/fuse/inode.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index e5dbecd..6da947d 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -14,6 +14,7 @@
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/parser.h>
#include <linux/statfs.h>
#include <linux/random.h>
@@ -28,10 +29,34 @@ static struct kmem_cache *fuse_inode_cachep;
struct list_head fuse_conn_list;
DEFINE_MUTEX(fuse_mutex);
+static int set_global_limit(const char *val, struct kernel_param *kp);
+
+unsigned max_user_bgreq;
+module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
+ &max_user_bgreq, 0644);
+__MODULE_PARM_TYPE(max_user_bgreq, "uint");
+MODULE_PARM_DESC(max_user_bgreq,
+ "Global limit for the maximum number of backgrounded requests an "
+ "unprivileged user can set");
+
+unsigned max_user_congthresh;
+module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
+ &max_user_congthresh, 0644);
+__MODULE_PARM_TYPE(max_user_congthresh, "uint");
+MODULE_PARM_DESC(max_user_congthresh,
+ "Global limit for the maximum congestion threshold an "
+ "unprivileged user can set");
+
#define FUSE_SUPER_MAGIC 0x65735546
#define FUSE_DEFAULT_BLKSIZE 512
+/** Maximum number of outstanding background requests */
+#define FUSE_DEFAULT_MAX_BACKGROUND 12
+
+/** Congestion starts at 75% of maximum */
+#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
+
struct fuse_mount_data {
int fd;
unsigned rootmode;
@@ -517,6 +542,8 @@ void fuse_conn_init(struct fuse_conn *fc)
INIT_LIST_HEAD(&fc->bg_queue);
INIT_LIST_HEAD(&fc->entry);
atomic_set(&fc->num_waiting, 0);
+ fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
+ fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
fc->khctr = 0;
fc->polled_files = RB_ROOT;
fc->reqctr = 0;
@@ -727,6 +754,54 @@ static const struct super_operations fuse_super_operations = {
.show_options = fuse_show_options,
};
+static void sanitize_global_limit(unsigned *limit)
+{
+ if (*limit == 0)
+ *limit = ((num_physpages << PAGE_SHIFT) >> 13) /
+ sizeof(struct fuse_req);
+
+ if (*limit >= 1 << 16)
+ *limit = (1 << 16) - 1;
+}
+
+static int set_global_limit(const char *val, struct kernel_param *kp)
+{
+ int rv;
+
+ rv = param_set_uint(val, kp);
+ if (rv)
+ return rv;
+
+ sanitize_global_limit((unsigned *)kp->arg);
+
+ return 0;
+}
+
+static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
+{
+ int cap_sys_admin = capable(CAP_SYS_ADMIN);
+
+ if (arg->minor < 13)
+ return;
+
+ sanitize_global_limit(&max_user_bgreq);
+ sanitize_global_limit(&max_user_congthresh);
+
+ if (arg->max_background) {
+ fc->max_background = arg->max_background;
+
+ if (!cap_sys_admin && fc->max_background > max_user_bgreq)
+ fc->max_background = max_user_bgreq;
+ }
+ if (arg->congestion_threshold) {
+ fc->congestion_threshold = arg->congestion_threshold;
+
+ if (!cap_sys_admin &&
+ fc->congestion_threshold > max_user_congthresh)
+ fc->congestion_threshold = max_user_congthresh;
+ }
+}
+
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
{
struct fuse_init_out *arg = &req->misc.init_out;
@@ -736,6 +811,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
else {
unsigned long ra_pages;
+ process_init_limits(fc, arg);
+
if (arg->minor >= 6) {
ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
if (arg->flags & FUSE_ASYNC_READ)
@@ -1150,6 +1227,9 @@ static int __init fuse_init(void)
if (res)
goto err_sysfs_cleanup;
+ sanitize_global_limit(&max_user_bgreq);
+ sanitize_global_limit(&max_user_congthresh);
+
return 0;
err_sysfs_cleanup:
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