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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
parent6f130478e24d810078c3f0ee292bcc4ec034dcce (diff)
parent79a9d99434b104c562f30f21b75317667f444793 (diff)
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')
-rw-r--r--fs/fuse/control.c138
-rw-r--r--fs/fuse/dev.c10
-rw-r--r--fs/fuse/fuse_i.h18
-rw-r--r--fs/fuse/inode.c80
4 files changed, 231 insertions, 15 deletions
diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index 99c99dfb0373..3773fd63d2f9 100644
--- a/fs/fuse/control.c
+++ b/fs/fuse/control.c
@@ -61,6 +61,121 @@ static ssize_t fuse_conn_waiting_read(struct file *file, char __user *buf,
return simple_read_from_buffer(buf, len, ppos, tmp, size);
}
+static ssize_t fuse_conn_limit_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos, unsigned val)
+{
+ char tmp[32];
+ size_t size = sprintf(tmp, "%u\n", val);
+
+ return simple_read_from_buffer(buf, len, ppos, tmp, size);
+}
+
+static ssize_t fuse_conn_limit_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos, unsigned *val,
+ unsigned global_limit)
+{
+ unsigned long t;
+ char tmp[32];
+ unsigned limit = (1 << 16) - 1;
+ int err;
+
+ if (*ppos || count >= sizeof(tmp) - 1)
+ return -EINVAL;
+
+ if (copy_from_user(tmp, buf, count))
+ return -EINVAL;
+
+ tmp[count] = '\0';
+
+ err = strict_strtoul(tmp, 0, &t);
+ if (err)
+ return err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ limit = min(limit, global_limit);
+
+ if (t > limit)
+ return -EINVAL;
+
+ *val = t;
+
+ return count;
+}
+
+static ssize_t fuse_conn_max_background_read(struct file *file,
+ char __user *buf, size_t len,
+ loff_t *ppos)
+{
+ struct fuse_conn *fc;
+ unsigned val;
+
+ fc = fuse_ctl_file_conn_get(file);
+ if (!fc)
+ return 0;
+
+ val = fc->max_background;
+ fuse_conn_put(fc);
+
+ return fuse_conn_limit_read(file, buf, len, ppos, val);
+}
+
+static ssize_t fuse_conn_max_background_write(struct file *file,
+ const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned val;
+ ssize_t ret;
+
+ ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
+ max_user_bgreq);
+ if (ret > 0) {
+ struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
+ if (fc) {
+ fc->max_background = val;
+ fuse_conn_put(fc);
+ }
+ }
+
+ return ret;
+}
+
+static ssize_t fuse_conn_congestion_threshold_read(struct file *file,
+ char __user *buf, size_t len,
+ loff_t *ppos)
+{
+ struct fuse_conn *fc;
+ unsigned val;
+
+ fc = fuse_ctl_file_conn_get(file);
+ if (!fc)
+ return 0;
+
+ val = fc->congestion_threshold;
+ fuse_conn_put(fc);
+
+ return fuse_conn_limit_read(file, buf, len, ppos, val);
+}
+
+static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
+ const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned val;
+ ssize_t ret;
+
+ ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
+ max_user_congthresh);
+ if (ret > 0) {
+ struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
+ if (fc) {
+ fc->congestion_threshold = val;
+ fuse_conn_put(fc);
+ }
+ }
+
+ return ret;
+}
+
static const struct file_operations fuse_ctl_abort_ops = {
.open = nonseekable_open,
.write = fuse_conn_abort_write,
@@ -71,6 +186,18 @@ static const struct file_operations fuse_ctl_waiting_ops = {
.read = fuse_conn_waiting_read,
};
+static const struct file_operations fuse_conn_max_background_ops = {
+ .open = nonseekable_open,
+ .read = fuse_conn_max_background_read,
+ .write = fuse_conn_max_background_write,
+};
+
+static const struct file_operations fuse_conn_congestion_threshold_ops = {
+ .open = nonseekable_open,
+ .read = fuse_conn_congestion_threshold_read,
+ .write = fuse_conn_congestion_threshold_write,
+};
+
static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
struct fuse_conn *fc,
const char *name,
@@ -127,9 +254,14 @@ int fuse_ctl_add_conn(struct fuse_conn *fc)
goto err;
if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400, 1,
- NULL, &fuse_ctl_waiting_ops) ||
+ NULL, &fuse_ctl_waiting_ops) ||
!fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200, 1,
- NULL, &fuse_ctl_abort_ops))
+ NULL, &fuse_ctl_abort_ops) ||
+ !fuse_ctl_add_dentry(parent, fc, "max_background", S_IFREG | 0600,
+ 1, NULL, &fuse_conn_max_background_ops) ||
+ !fuse_ctl_add_dentry(parent, fc, "congestion_threshold",
+ S_IFREG | 0600, 1, NULL,
+ &fuse_conn_congestion_threshold_ops))
goto err;
return 0;
@@ -156,7 +288,7 @@ void fuse_ctl_remove_conn(struct fuse_conn *fc)
d_drop(dentry);
dput(dentry);
}
- fuse_control_sb->s_root->d_inode->i_nlink--;
+ drop_nlink(fuse_control_sb->s_root->d_inode);
}
static int fuse_ctl_fill_super(struct super_block *sb, void *data, int silent)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 6484eb75acd6..51d9e33d634f 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -250,7 +250,7 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
static void flush_bg_queue(struct fuse_conn *fc)
{
- while (fc->active_background < FUSE_MAX_BACKGROUND &&
+ while (fc->active_background < fc->max_background &&
!list_empty(&fc->bg_queue)) {
struct fuse_req *req;
@@ -280,11 +280,11 @@ __releases(&fc->lock)
list_del(&req->intr_entry);
req->state = FUSE_REQ_FINISHED;
if (req->background) {
- if (fc->num_background == FUSE_MAX_BACKGROUND) {
+ if (fc->num_background == fc->max_background) {
fc->blocked = 0;
wake_up_all(&fc->blocked_waitq);
}
- if (fc->num_background == FUSE_CONGESTION_THRESHOLD &&
+ if (fc->num_background == fc->congestion_threshold &&
fc->connected && fc->bdi_initialized) {
clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
@@ -410,9 +410,9 @@ static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
{
req->background = 1;
fc->num_background++;
- if (fc->num_background == FUSE_MAX_BACKGROUND)
+ if (fc->num_background == fc->max_background)
fc->blocked = 1;
- if (fc->num_background == FUSE_CONGESTION_THRESHOLD &&
+ if (fc->num_background == fc->congestion_threshold &&
fc->bdi_initialized) {
set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 52b641fc0faf..fc9c79feb5f7 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -25,12 +25,6 @@
/** Max number of pages that can be used in a single read request */
#define FUSE_MAX_PAGES_PER_REQ 32
-/** Maximum number of outstanding background requests */
-#define FUSE_MAX_BACKGROUND 12
-
-/** Congestion starts at 75% of maximum */
-#define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100)
-
/** Bias for fi->writectr, meaning new writepages must not be sent */
#define FUSE_NOWRITE INT_MIN
@@ -38,7 +32,7 @@
#define FUSE_NAME_MAX 1024
/** Number of dentries for each connection in the control filesystem */
-#define FUSE_CTL_NUM_DENTRIES 3
+#define FUSE_CTL_NUM_DENTRIES 5
/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
module will check permissions based on the file mode. Otherwise no
@@ -55,6 +49,10 @@ extern struct list_head fuse_conn_list;
/** Global mutex protecting fuse_conn_list and the control filesystem */
extern struct mutex fuse_mutex;
+/** Module parameters */
+extern unsigned max_user_bgreq;
+extern unsigned max_user_congthresh;
+
/** FUSE inode */
struct fuse_inode {
/** Inode data */
@@ -349,6 +347,12 @@ struct fuse_conn {
/** rbtree of fuse_files waiting for poll events indexed by ph */
struct rb_root polled_files;
+ /** Maximum number of outstanding background requests */
+ unsigned max_background;
+
+ /** Number of background requests at which congestion starts */
+ unsigned congestion_threshold;
+
/** Number of requests currently in the background */
unsigned num_background;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index e5dbecd87b0f..6da947daabda 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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