Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2)   FUSE: Filesystem in Userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)   This program can be distributed under the terms of the GNU GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)   See the file COPYING.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include "fuse_i.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/fs_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #define FUSE_CTL_SUPER_MAGIC 0x65735543
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  * This is non-NULL when the single instance of the control filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  * exists.  Protected by fuse_mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static struct super_block *fuse_control_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) static struct fuse_conn *fuse_ctl_file_conn_get(struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	struct fuse_conn *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	mutex_lock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	fc = file_inode(file)->i_private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	if (fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 		fc = fuse_conn_get(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	mutex_unlock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	return fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static ssize_t fuse_conn_abort_write(struct file *file, const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 				     size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	if (fc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 		if (fc->abort_err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 			fc->aborted = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		fuse_abort_conn(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		fuse_conn_put(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) static ssize_t fuse_conn_waiting_read(struct file *file, char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 				      size_t len, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	char tmp[32];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	size_t size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	if (!*ppos) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		long value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		if (!fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		value = atomic_read(&fc->num_waiting);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 		file->private_data = (void *)value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 		fuse_conn_put(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	size = sprintf(tmp, "%ld\n", (long)file->private_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	return simple_read_from_buffer(buf, len, ppos, tmp, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) static ssize_t fuse_conn_limit_read(struct file *file, char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 				    size_t len, loff_t *ppos, unsigned val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	char tmp[32];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	size_t size = sprintf(tmp, "%u\n", val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	return simple_read_from_buffer(buf, len, ppos, tmp, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) static ssize_t fuse_conn_limit_write(struct file *file, const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 				     size_t count, loff_t *ppos, unsigned *val,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 				     unsigned global_limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	unsigned long t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	unsigned limit = (1 << 16) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	if (*ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	err = kstrtoul_from_user(buf, count, 0, &t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	if (!capable(CAP_SYS_ADMIN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		limit = min(limit, global_limit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	if (t > limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	*val = t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) static ssize_t fuse_conn_max_background_read(struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 					     char __user *buf, size_t len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 					     loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	struct fuse_conn *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	unsigned val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	fc = fuse_ctl_file_conn_get(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	if (!fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	val = READ_ONCE(fc->max_background);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	fuse_conn_put(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	return fuse_conn_limit_read(file, buf, len, ppos, val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) static ssize_t fuse_conn_max_background_write(struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 					      const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 					      size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	unsigned val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 				    max_user_bgreq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	if (ret > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		if (fc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 			spin_lock(&fc->bg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 			fc->max_background = val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 			fc->blocked = fc->num_background >= fc->max_background;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 			if (!fc->blocked)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 				wake_up(&fc->blocked_waitq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 			spin_unlock(&fc->bg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 			fuse_conn_put(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) static ssize_t fuse_conn_congestion_threshold_read(struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 						   char __user *buf, size_t len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 						   loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	struct fuse_conn *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	unsigned val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	fc = fuse_ctl_file_conn_get(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	if (!fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	val = READ_ONCE(fc->congestion_threshold);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	fuse_conn_put(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	return fuse_conn_limit_read(file, buf, len, ppos, val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 						    const char __user *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 						    size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	unsigned val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	struct fuse_conn *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	struct fuse_mount *fm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 				    max_user_congthresh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	if (ret <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	fc = fuse_ctl_file_conn_get(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	if (!fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	down_read(&fc->killsb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	spin_lock(&fc->bg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	fc->congestion_threshold = val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	 * Get any fuse_mount belonging to this fuse_conn; s_bdi is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	 * shared between all of them
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	if (!list_empty(&fc->mounts)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		fm = list_first_entry(&fc->mounts, struct fuse_mount, fc_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		if (fc->num_background < fc->congestion_threshold) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			clear_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 			clear_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 			set_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 			set_bdi_congested(fm->sb->s_bdi, BLK_RW_ASYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	spin_unlock(&fc->bg_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	up_read(&fc->killsb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	fuse_conn_put(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) static const struct file_operations fuse_ctl_abort_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	.open = nonseekable_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	.write = fuse_conn_abort_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) static const struct file_operations fuse_ctl_waiting_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	.open = nonseekable_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	.read = fuse_conn_waiting_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) static const struct file_operations fuse_conn_max_background_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	.open = nonseekable_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	.read = fuse_conn_max_background_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	.write = fuse_conn_max_background_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) static const struct file_operations fuse_conn_congestion_threshold_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	.open = nonseekable_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	.read = fuse_conn_congestion_threshold_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	.write = fuse_conn_congestion_threshold_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	.llseek = no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) static struct dentry *fuse_ctl_add_dentry(struct dentry *parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 					  struct fuse_conn *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 					  const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 					  int mode, int nlink,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 					  const struct inode_operations *iop,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 					  const struct file_operations *fop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	struct dentry *dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	BUG_ON(fc->ctl_ndents >= FUSE_CTL_NUM_DENTRIES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	dentry = d_alloc_name(parent, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	if (!dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	inode = new_inode(fuse_control_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	if (!inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 		dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	inode->i_ino = get_next_ino();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	inode->i_mode = mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	inode->i_uid = fc->user_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	inode->i_gid = fc->group_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	/* setting ->i_op to NULL is not allowed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	if (iop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 		inode->i_op = iop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	inode->i_fop = fop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	set_nlink(inode, nlink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	inode->i_private = fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	d_add(dentry, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	fc->ctl_dentry[fc->ctl_ndents++] = dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	return dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)  * Add a connection to the control filesystem (if it exists).  Caller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)  * must hold fuse_mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) int fuse_ctl_add_conn(struct fuse_conn *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	struct dentry *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	char name[32];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	if (!fuse_control_sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	parent = fuse_control_sb->s_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	inc_nlink(d_inode(parent));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	sprintf(name, "%u", fc->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	parent = fuse_ctl_add_dentry(parent, fc, name, S_IFDIR | 0500, 2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 				     &simple_dir_inode_operations,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 				     &simple_dir_operations);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	if (!parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	if (!fuse_ctl_add_dentry(parent, fc, "waiting", S_IFREG | 0400, 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 				 NULL, &fuse_ctl_waiting_ops) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 	    !fuse_ctl_add_dentry(parent, fc, "abort", S_IFREG | 0200, 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 				 NULL, &fuse_ctl_abort_ops) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	    !fuse_ctl_add_dentry(parent, fc, "max_background", S_IFREG | 0600,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 				 1, NULL, &fuse_conn_max_background_ops) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	    !fuse_ctl_add_dentry(parent, fc, "congestion_threshold",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 				 S_IFREG | 0600, 1, NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 				 &fuse_conn_congestion_threshold_ops))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 		goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)  err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 	fuse_ctl_remove_conn(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)  * Remove a connection from the control filesystem (if it exists).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)  * Caller must hold fuse_mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) void fuse_ctl_remove_conn(struct fuse_conn *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	if (!fuse_control_sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	for (i = fc->ctl_ndents - 1; i >= 0; i--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 		struct dentry *dentry = fc->ctl_dentry[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 		d_inode(dentry)->i_private = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		if (!i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 			/* Get rid of submounts: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 			d_invalidate(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 		dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 	drop_nlink(d_inode(fuse_control_sb->s_root));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) static int fuse_ctl_fill_super(struct super_block *sb, struct fs_context *fctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	static const struct tree_descr empty_descr = {""};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	struct fuse_conn *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	err = simple_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 	mutex_lock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	BUG_ON(fuse_control_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	fuse_control_sb = sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	list_for_each_entry(fc, &fuse_conn_list, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 		err = fuse_ctl_add_conn(fc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 		if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 			fuse_control_sb = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 			mutex_unlock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	mutex_unlock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) static int fuse_ctl_get_tree(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 	return get_tree_single(fc, fuse_ctl_fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) static const struct fs_context_operations fuse_ctl_context_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	.get_tree	= fuse_ctl_get_tree,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) static int fuse_ctl_init_fs_context(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 	fc->ops = &fuse_ctl_context_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) static void fuse_ctl_kill_sb(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 	struct fuse_conn *fc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 	mutex_lock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 	fuse_control_sb = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 	list_for_each_entry(fc, &fuse_conn_list, entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 		fc->ctl_ndents = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 	mutex_unlock(&fuse_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 	kill_litter_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) static struct file_system_type fuse_ctl_fs_type = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 	.name		= "fusectl",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 	.init_fs_context = fuse_ctl_init_fs_context,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 	.kill_sb	= fuse_ctl_kill_sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) MODULE_ALIAS_FS("fusectl");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) int __init fuse_ctl_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 	return register_filesystem(&fuse_ctl_fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) void __exit fuse_ctl_cleanup(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 	unregister_filesystem(&fuse_ctl_fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) }