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UBIFS: introduce debugfs helpers 

Separate out pieces of code from the debugfs file read/write functions and
create separate 'interpret_user_input()'/'provide_user_output()' helpers. These
helpers will be needed in one of the following patches, so this is just a
preparational change.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This commit is contained in:
Artem Bityutskiy 2011-06-03 09:58:23 +03:00 committed by Artem Bityutskiy
parent 7dae997de6
commit 28488fc28a
1 changed files with 56 additions and 20 deletions
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76
fs/ubifs/debug.c
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@ -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;