diff options
| -rw-r--r-- | fs/ubifs/debug.c | 76 |
1 files changed, 56 insertions, 20 deletions
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c index 24a85073ac6c..b98638eb0fcb 100644 --- a/fs/ubifs/debug.c +++ b/fs/ubifs/debug.c @@ -2820,13 +2820,39 @@ static int dfs_file_open(struct inode *inode, struct file *file) return nonseekable_open(inode, file); } +/** + * provide_user_output - provide output to the user reading a debugfs file. + * @val: boolean value for the answer + * @u: the buffer to store the answer at + * @count: size of the buffer + * @ppos: position in the @u output buffer + * + * This is a simple helper function which stores @val boolean value in the user + * buffer when the user reads one of UBIFS debugfs files. Returns amount of + * bytes written to @u in case of success and a negative error code in case of + * failure. + */ +static int provide_user_output(int val, char __user *u, size_t count, + loff_t *ppos) +{ + char buf[3]; + + if (val) + buf[0] = '1'; + else + buf[0] = '0'; + buf[1] = '\n'; + buf[2] = 0x00; + + return simple_read_from_buffer(u, count, ppos, buf, 2); +} + static ssize_t dfs_file_read(struct file *file, char __user *u, size_t count, loff_t *ppos) { struct dentry *dent = file->f_path.dentry; struct ubifs_info *c = file->private_data; struct ubifs_debug_info *d = c->dbg; - char buf[3]; int val; if (dent == d->dfs_chk_gen) @@ -2844,14 +2870,33 @@ static ssize_t dfs_file_read(struct file *file, char __user *u, size_t count, else return -EINVAL; - if (val) - buf[0] = '1'; - else - buf[0] = '0'; - buf[1] = '\n'; - buf[2] = 0x00; + return provide_user_output(val, u, count, ppos); +} - return simple_read_from_buffer(u, count, ppos, buf, 2); +/** + * interpret_user_input - interpret user debugfs file input. + * @u: user-provided buffer with the input + * @count: buffer size + * + * This is a helper function which interpret user input to a boolean UBIFS + * debugfs file. Returns %0 or %1 in case of success and a negative error code + * in case of failure. + */ +static int interpret_user_input(const char __user *u, size_t count) +{ + size_t buf_size; + char buf[8]; + + buf_size = min_t(size_t, count, (sizeof(buf) - 1)); + if (copy_from_user(buf, u, buf_size)) + return -EFAULT; + + if (buf[0] == '1') + return 1; + else if (buf[0] == '0') + return 0; + + return -EINVAL; } static ssize_t dfs_file_write(struct file *file, const char __user *u, @@ -2860,8 +2905,6 @@ static ssize_t dfs_file_write(struct file *file, const char __user *u, struct ubifs_info *c = file->private_data; struct ubifs_debug_info *d = c->dbg; struct dentry *dent = file->f_path.dentry; - size_t buf_size; - char buf[8]; int val; /* @@ -2891,16 +2934,9 @@ static ssize_t dfs_file_write(struct file *file, const char __user *u, return count; } - buf_size = min_t(size_t, count, (sizeof(buf) - 1)); - if (copy_from_user(buf, u, buf_size)) - return -EFAULT; - - if (buf[0] == '1') - val = 1; - else if (buf[0] == '0') - val = 0; - else - return -EINVAL; + val = interpret_user_input(u, count); + if (val < 0) + return val; if (dent == d->dfs_chk_gen) d->chk_gen = val; |