Release 4.9 fs/readdir.c

/*
 *  linux/fs/readdir.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 */

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
#include <linux/dirent.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>

#include <asm/uaccess.h>



int iterate_dir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	bool shared = false;
	int res = -ENOTDIR;
	if (file->f_op->iterate_shared)
		shared = true;
	else if (!file->f_op->iterate)
		goto out;

	res = security_file_permission(file, MAY_READ);
	if (res)
		goto out;

	if (shared) {
		inode_lock_shared(inode);
	} else {
		res = down_write_killable(&inode->i_rwsem);
		if (res)
			goto out;
	}

	res = -ENOENT;
	if (!IS_DEADDIR(inode)) {
		ctx->pos = file->f_pos;
		if (shared)
			res = file->f_op->iterate_shared(file, ctx);
		else
			res = file->f_op->iterate(file, ctx);
		file->f_pos = ctx->pos;
		fsnotify_access(file);
		file_accessed(file);
	}
	if (shared)
		inode_unlock_shared(inode);
	else
		inode_unlock(inode);
out:
	return res;
}
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al viro
al viro
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57.00%
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46.67%
pre-git
pre-git
62
31.00%
3
20.00%
stephen d. smalley
stephen d. smalley
11
5.50%
1
6.67%
heinrich schuchardt
heinrich schuchardt
5
2.50%
1
6.67%
greg kroah-hartman
greg kroah-hartman
5
2.50%
2
13.33%
andrew morton
andrew morton
3
1.50%
1
6.67%
Total
200
100.00%
15
100.00%


EXPORT_SYMBOL(iterate_dir);

/*
 * Traditional linux readdir() handling..
 *
 * "count=1" is a special case, meaning that the buffer is one
 * dirent-structure in size and that the code can't handle more
 * anyway. Thus the special "fillonedir()" function for that
 * case (the low-level handlers don't need to care about this).
 */

#ifdef __ARCH_WANT_OLD_READDIR


struct old_linux_dirent {
	
unsigned long	d_ino;
	
unsigned long	d_offset;
	
unsigned short	d_namlen;
	
char		d_name[1];
};


struct readdir_callback {
	
struct dir_context ctx;
	
struct old_linux_dirent __user * dirent;
	
int result;
};



static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
		      loff_t offset, u64 ino, unsigned int d_type)
{
	struct readdir_callback *buf =
		container_of(ctx, struct readdir_callback, ctx);
	struct old_linux_dirent __user * dirent;
	unsigned long d_ino;

	if (buf->result)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->result = -EOVERFLOW;
		return -EOVERFLOW;
	}
	buf->result++;
	dirent = buf->dirent;
	if (!access_ok(VERIFY_WRITE, dirent,
			(unsigned long)(dirent->d_name + namlen + 1) -
				(unsigned long)dirent))
		goto efault;
	if (	__put_user(d_ino, &dirent->d_ino) ||
		__put_user(offset, &dirent->d_offset) ||
		__put_user(namlen, &dirent->d_namlen) ||
		__copy_to_user(dirent->d_name, name, namlen) ||
		__put_user(0, dirent->d_name + namlen))
		goto efault;
	return 0;
efault:
	buf->result = -EFAULT;
	return -EFAULT;
}

Contributors
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CommitProp
pre-git
pre-git
99
46.26%
4
36.36%
andrew morton
andrew morton
64
29.91%
2
18.18%
david howells
david howells
30
14.02%
1
9.09%
miklos szeredi
miklos szeredi
10
4.67%
1
9.09%
al viro
al viro
9
4.21%
1
9.09%
linus torvalds
linus torvalds
2
0.93%
2
18.18%
Total
214
100.00%
11
100.00%


SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
		struct old_linux_dirent __user *, dirent, unsigned int, count)
{
	int error;
	struct fd f = fdget_pos(fd);
	struct readdir_callback buf = {
		.ctx.actor = fillonedir,
		.dirent = dirent
	};

	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (buf.result)
		error = buf.result;

	fdput_pos(f);
	return error;
}

#endif /* __ARCH_WANT_OLD_READDIR */

/*
 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
 * interface. 
 */

struct linux_dirent {
	
unsigned long	d_ino;
	
unsigned long	d_off;
	
unsigned short	d_reclen;
	
char		d_name[1];
};


struct getdents_callback {
	
struct dir_context ctx;
	
struct linux_dirent __user * current_dir;
	
struct linux_dirent __user * previous;
	
int count;
	
int error;
};



static int filldir(struct dir_context *ctx, const char *name, int namlen,
		   loff_t offset, u64 ino, unsigned int d_type)
{
	struct linux_dirent __user * dirent;
	struct getdents_callback *buf =
		container_of(ctx, struct getdents_callback, ctx);
	unsigned long d_ino;
	int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
		sizeof(long));

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->error = -EOVERFLOW;
		return -EOVERFLOW;
	}
	dirent = buf->previous;
	if (dirent) {
		if (signal_pending(current))
			return -EINTR;
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(d_ino, &dirent->d_ino))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	if (__put_user(d_type, (char __user *) dirent + reclen - 1))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

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pre-git
pre-git
147
48.68%
7
31.82%
andrew morton
andrew morton
55
18.21%
3
13.64%
david howells
david howells
30
9.93%
1
4.55%
linus torvalds
linus torvalds
28
9.27%
5
22.73%
theodore tso
theodore tso
11
3.64%
1
4.55%
al viro
al viro
10
3.31%
2
9.09%
miklos szeredi
miklos szeredi
10
3.31%
1
4.55%
milind arun choudhary
milind arun choudhary
6
1.99%
1
4.55%
kevin winchester
kevin winchester
5
1.66%
1
4.55%
Total
302
100.00%
22
100.00%


SYSCALL_DEFINE3(getdents, unsigned int, fd,
		struct linux_dirent __user *, dirent, unsigned int, count)
{
	struct fd f;
	struct linux_dirent __user * lastdirent;
	struct getdents_callback buf = {
		.ctx.actor = filldir,
		.count = count,
		.current_dir = dirent
	};
	int error;

	if (!access_ok(VERIFY_WRITE, dirent, count))
		return -EFAULT;

	f = fdget_pos(fd);
	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(buf.ctx.pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fdput_pos(f);
	return error;
}


struct getdents_callback64 {
	
struct dir_context ctx;
	
struct linux_dirent64 __user * current_dir;
	
struct linux_dirent64 __user * previous;
	
int count;
	
int error;
};



static int filldir64(struct dir_context *ctx, const char *name, int namlen,
		     loff_t offset, u64 ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct getdents_callback64 *buf =
		container_of(ctx, struct getdents_callback64, ctx);
	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
		sizeof(u64));

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	dirent = buf->previous;
	if (dirent) {
		if (signal_pending(current))
			return -EINTR;
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(ino, &dirent->d_ino))
		goto efault;
	if (__put_user(0, &dirent->d_off))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (__put_user(d_type, &dirent->d_type))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

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pre-git
142
51.82%
1
7.14%
andrew morton
andrew morton
93
33.94%
3
21.43%
theodore tso
theodore tso
11
4.01%
1
7.14%
miklos szeredi
miklos szeredi
10
3.65%
1
7.14%
linus torvalds
linus torvalds
6
2.19%
5
35.71%
milind arun choudhary
milind arun choudhary
6
2.19%
1
7.14%
kevin winchester
kevin winchester
5
1.82%
1
7.14%
david howells
david howells
1
0.36%
1
7.14%
Total
274
100.00%
14
100.00%


SYSCALL_DEFINE3(getdents64, unsigned int, fd,
		struct linux_dirent64 __user *, dirent, unsigned int, count)
{
	struct fd f;
	struct linux_dirent64 __user * lastdirent;
	struct getdents_callback64 buf = {
		.ctx.actor = filldir64,
		.count = count,
		.current_dir = dirent
	};
	int error;

	if (!access_ok(VERIFY_WRITE, dirent, count))
		return -EFAULT;

	f = fdget_pos(fd);
	if (!f.file)
		return -EBADF;

	error = iterate_dir(f.file, &buf.ctx);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = buf.ctx.pos;
		if (__put_user(d_off, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fdput_pos(f);
	return error;
}
Overall Contributors
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766
47.99%
17
26.98%
al viro
al viro
281
17.61%
14
22.22%
andrew morton
andrew morton
251
15.73%
8
12.70%
david howells
david howells
61
3.82%
1
1.59%
linus torvalds
linus torvalds
61
3.82%
6
9.52%
heiko carstens
heiko carstens
48
3.01%
2
3.17%
miklos szeredi
miklos szeredi
30
1.88%
1
1.59%
theodore tso
theodore tso
22
1.38%
1
1.59%
milind arun choudhary
milind arun choudhary
15
0.94%
1
1.59%
kevin winchester
kevin winchester
13
0.81%
1
1.59%
stephen d. smalley
stephen d. smalley
11
0.69%
1
1.59%
greg kroah-hartman
greg kroah-hartman
8
0.50%
3
4.76%
heinrich schuchardt
heinrich schuchardt
8
0.50%
1
1.59%
arnaldo carvalho de melo
arnaldo carvalho de melo
6
0.38%
1
1.59%
dave jones
dave jones
4
0.25%
1
1.59%
adam kropelin
adam kropelin
4
0.25%
1
1.59%
arnd bergmann
arnd bergmann
3
0.19%
1
1.59%
prasanna meda
prasanna meda
3
0.19%
1
1.59%
paul gortmaker
paul gortmaker
1
0.06%
1
1.59%
Total
1596
100.00%
63
100.00%
  
Directory: fs