From 79a9d99434b104c562f30f21b75317667f444793 Mon Sep 17 00:00:00 2001 From: Csaba Henk Date: Wed, 26 Aug 2009 19:18:24 +0200 Subject: 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 Signed-off-by: Miklos Szeredi --- fs/fuse/control.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 134 insertions(+), 2 deletions(-) (limited to 'fs/fuse/control.c') diff --git a/fs/fuse/control.c b/fs/fuse/control.c index 218d514924c..3773fd63d2f 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; -- cgit v1.2.3-18-g5258