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authorCsaba Henk <csaba@gluster.com>2009-08-26 19:18:24 +0200
committerMiklos Szeredi <mszeredi@suse.cz>2009-09-16 14:15:29 +0200
commit79a9d99434b104c562f30f21b75317667f444793 (patch)
tree181900c493e9aa0322b47dbcf2aa8251a956dd30 /fs/fuse/control.c
parentfuse: limit user-specified values of max background requests (diff)
downloadlinux-79a9d99434b104c562f30f21b75317667f444793.tar.xz
linux-79a9d99434b104c562f30f21b75317667f444793.zip
fuse: add fusectl interface to max_background
Make the max_background and congestion_threshold parameters of a FUSE mount tunable at runtime by adding the respective knobs to its directory within the fusectl filesystem. Signed-off-by: Csaba Henk <csaba@gluster.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Diffstat (limited to 'fs/fuse/control.c')
-rw-r--r--fs/fuse/control.c136
1 files changed, 134 insertions, 2 deletions
diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index 218d514924c0..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;