From 79a9d99434b104c562f30f21b75317667f444793 Mon Sep 17 00:00:00 2001 From: Csaba Henk Date: Wed, 26 Aug 2009 19:18:24 +0200 Subject: [PATCH] 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 +++++++++++++++++++++++++++++++++++++++++++++- fs/fuse/fuse_i.h | 6 +- fs/fuse/inode.c | 4 +- 3 files changed, 141 insertions(+), 5 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; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 6bcfab04396f..fc9c79feb5f7 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -32,7 +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 @@ -49,6 +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 */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index e54ddbda208c..8f9aca8d4ad5 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -31,7 +31,7 @@ DEFINE_MUTEX(fuse_mutex); static int set_global_limit(const char *val, struct kernel_param *kp); -static unsigned max_user_bgreq; +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"); @@ -39,7 +39,7 @@ MODULE_PARM_DESC(max_user_bgreq, "Global limit for the maximum number of backgrounded requests an " "unprivileged user can set"); -static unsigned max_user_congthresh; +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");