Initial import

1 files changed, 625 insertions, 0 deletions

diff --git a/fs/ioctl.c b/fs/ioctl.c
new file mode 100644
index 000000000..5d01d2638
--- /dev/null
+++ b/fs/ioctl.c
@@ -0,0 +1,625 @@
+/*
+ *  linux/fs/ioctl.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/syscalls.h>
+#include <linux/mm.h>
+#include <linux/capability.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/export.h>
+#include <linux/uaccess.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h>
+#include <linux/falloc.h>
+
+#include <asm/ioctls.h>
+
+/* So that the fiemap access checks can't overflow on 32 bit machines. */
+#define FIEMAP_MAX_EXTENTS	(UINT_MAX / sizeof(struct fiemap_extent))
+
+/**
+ * vfs_ioctl - call filesystem specific ioctl methods
+ * @filp:	open file to invoke ioctl method on
+ * @cmd:	ioctl command to execute
+ * @arg:	command-specific argument for ioctl
+ *
+ * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
+ * returns -ENOTTY.
+ *
+ * Returns 0 on success, -errno on error.
+ */
+static long vfs_ioctl(struct file *filp, unsigned int cmd,
+		      unsigned long arg)
+{
+	int error = -ENOTTY;
+
+	if (!filp->f_op->unlocked_ioctl)
+		goto out;
+
+	error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
+	if (error == -ENOIOCTLCMD)
+		error = -ENOTTY;
+ out:
+	return error;
+}
+
+static int ioctl_fibmap(struct file *filp, int __user *p)
+{
+	struct address_space *mapping = filp->f_mapping;
+	int res, block;
+
+	/* do we support this mess? */
+	if (!mapping->a_ops->bmap)
+		return -EINVAL;
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+	res = get_user(block, p);
+	if (res)
+		return res;
+	res = mapping->a_ops->bmap(mapping, block);
+	return put_user(res, p);
+}
+
+/**
+ * fiemap_fill_next_extent - Fiemap helper function
+ * @fieinfo:	Fiemap context passed into ->fiemap
+ * @logical:	Extent logical start offset, in bytes
+ * @phys:	Extent physical start offset, in bytes
+ * @len:	Extent length, in bytes
+ * @flags:	FIEMAP_EXTENT flags that describe this extent
+ *
+ * Called from file system ->fiemap callback. Will populate extent
+ * info as passed in via arguments and copy to user memory. On
+ * success, extent count on fieinfo is incremented.
+ *
+ * Returns 0 on success, -errno on error, 1 if this was the last
+ * extent that will fit in user array.
+ */
+#define SET_UNKNOWN_FLAGS	(FIEMAP_EXTENT_DELALLOC)
+#define SET_NO_UNMOUNTED_IO_FLAGS	(FIEMAP_EXTENT_DATA_ENCRYPTED)
+#define SET_NOT_ALIGNED_FLAGS	(FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
+int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
+			    u64 phys, u64 len, u32 flags)
+{
+	struct fiemap_extent extent;
+	struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
+
+	/* only count the extents */
+	if (fieinfo->fi_extents_max == 0) {
+		fieinfo->fi_extents_mapped++;
+		return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
+	}
+
+	if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
+		return 1;
+
+	if (flags & SET_UNKNOWN_FLAGS)
+		flags |= FIEMAP_EXTENT_UNKNOWN;
+	if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
+		flags |= FIEMAP_EXTENT_ENCODED;
+	if (flags & SET_NOT_ALIGNED_FLAGS)
+		flags |= FIEMAP_EXTENT_NOT_ALIGNED;
+
+	memset(&extent, 0, sizeof(extent));
+	extent.fe_logical = logical;
+	extent.fe_physical = phys;
+	extent.fe_length = len;
+	extent.fe_flags = flags;
+
+	dest += fieinfo->fi_extents_mapped;
+	if (copy_to_user(dest, &extent, sizeof(extent)))
+		return -EFAULT;
+
+	fieinfo->fi_extents_mapped++;
+	if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
+		return 1;
+	return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
+}
+EXPORT_SYMBOL(fiemap_fill_next_extent);
+
+/**
+ * fiemap_check_flags - check validity of requested flags for fiemap
+ * @fieinfo:	Fiemap context passed into ->fiemap
+ * @fs_flags:	Set of fiemap flags that the file system understands
+ *
+ * Called from file system ->fiemap callback. This will compute the
+ * intersection of valid fiemap flags and those that the fs supports. That
+ * value is then compared against the user supplied flags. In case of bad user
+ * flags, the invalid values will be written into the fieinfo structure, and
+ * -EBADR is returned, which tells ioctl_fiemap() to return those values to
+ * userspace. For this reason, a return code of -EBADR should be preserved.
+ *
+ * Returns 0 on success, -EBADR on bad flags.
+ */
+int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
+{
+	u32 incompat_flags;
+
+	incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
+	if (incompat_flags) {
+		fieinfo->fi_flags = incompat_flags;
+		return -EBADR;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(fiemap_check_flags);
+
+static int fiemap_check_ranges(struct super_block *sb,
+			       u64 start, u64 len, u64 *new_len)
+{
+	u64 maxbytes = (u64) sb->s_maxbytes;
+
+	*new_len = len;
+
+	if (len == 0)
+		return -EINVAL;
+
+	if (start > maxbytes)
+		return -EFBIG;
+
+	/*
+	 * Shrink request scope to what the fs can actually handle.
+	 */
+	if (len > maxbytes || (maxbytes - len) < start)
+		*new_len = maxbytes - start;
+
+	return 0;
+}
+
+static int ioctl_fiemap(struct file *filp, unsigned long arg)
+{
+	struct fiemap fiemap;
+	struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
+	struct fiemap_extent_info fieinfo = { 0, };
+	struct inode *inode = file_inode(filp);
+	struct super_block *sb = inode->i_sb;
+	u64 len;
+	int error;
+
+	if (!inode->i_op->fiemap)
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
+		return -EFAULT;
+
+	if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
+		return -EINVAL;
+
+	error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
+				    &len);
+	if (error)
+		return error;
+
+	fieinfo.fi_flags = fiemap.fm_flags;
+	fieinfo.fi_extents_max = fiemap.fm_extent_count;
+	fieinfo.fi_extents_start = ufiemap->fm_extents;
+
+	if (fiemap.fm_extent_count != 0 &&
+	    !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start,
+		       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
+		return -EFAULT;
+
+	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
+		filemap_write_and_wait(inode->i_mapping);
+
+	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
+	fiemap.fm_flags = fieinfo.fi_flags;
+	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
+	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
+		error = -EFAULT;
+
+	return error;
+}
+
+#ifdef CONFIG_BLOCK
+
+static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
+{
+	return (offset >> inode->i_blkbits);
+}
+
+static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
+{
+	return (blk << inode->i_blkbits);
+}
+
+/**
+ * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
+ * @inode: the inode to map
+ * @fieinfo: the fiemap info struct that will be passed back to userspace
+ * @start: where to start mapping in the inode
+ * @len: how much space to map
+ * @get_block: the fs's get_block function
+ *
+ * This does FIEMAP for block based inodes.  Basically it will just loop
+ * through get_block until we hit the number of extents we want to map, or we
+ * go past the end of the file and hit a hole.
+ *
+ * If it is possible to have data blocks beyond a hole past @inode->i_size, then
+ * please do not use this function, it will stop at the first unmapped block
+ * beyond i_size.
+ *
+ * If you use this function directly, you need to do your own locking. Use
+ * generic_block_fiemap if you want the locking done for you.
+ */
+
+int __generic_block_fiemap(struct inode *inode,
+			   struct fiemap_extent_info *fieinfo, loff_t start,
+			   loff_t len, get_block_t *get_block)
+{
+	struct buffer_head map_bh;
+	sector_t start_blk, last_blk;
+	loff_t isize = i_size_read(inode);
+	u64 logical = 0, phys = 0, size = 0;
+	u32 flags = FIEMAP_EXTENT_MERGED;
+	bool past_eof = false, whole_file = false;
+	int ret = 0;
+
+	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
+	if (ret)
+		return ret;
+
+	/*
+	 * Either the i_mutex or other appropriate locking needs to be held
+	 * since we expect isize to not change at all through the duration of
+	 * this call.
+	 */
+	if (len >= isize) {
+		whole_file = true;
+		len = isize;
+	}
+
+	/*
+	 * Some filesystems can't deal with being asked to map less than
+	 * blocksize, so make sure our len is at least block length.
+	 */
+	if (logical_to_blk(inode, len) == 0)
+		len = blk_to_logical(inode, 1);
+
+	start_blk = logical_to_blk(inode, start);
+	last_blk = logical_to_blk(inode, start + len - 1);
+
+	do {
+		/*
+		 * we set b_size to the total size we want so it will map as
+		 * many contiguous blocks as possible at once
+		 */
+		memset(&map_bh, 0, sizeof(struct buffer_head));
+		map_bh.b_size = len;
+
+		ret = get_block(inode, start_blk, &map_bh, 0);
+		if (ret)
+			break;
+
+		/* HOLE */
+		if (!buffer_mapped(&map_bh)) {
+			start_blk++;
+
+			/*
+			 * We want to handle the case where there is an
+			 * allocated block at the front of the file, and then
+			 * nothing but holes up to the end of the file properly,
+			 * to make sure that extent at the front gets properly
+			 * marked with FIEMAP_EXTENT_LAST
+			 */
+			if (!past_eof &&
+			    blk_to_logical(inode, start_blk) >= isize)
+				past_eof = 1;
+
+			/*
+			 * First hole after going past the EOF, this is our
+			 * last extent
+			 */
+			if (past_eof && size) {
+				flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
+				ret = fiemap_fill_next_extent(fieinfo, logical,
+							      phys, size,
+							      flags);
+			} else if (size) {
+				ret = fiemap_fill_next_extent(fieinfo, logical,
+							      phys, size, flags);
+				size = 0;
+			}
+
+			/* if we have holes up to/past EOF then we're done */
+			if (start_blk > last_blk || past_eof || ret)
+				break;
+		} else {
+			/*
+			 * We have gone over the length of what we wanted to
+			 * map, and it wasn't the entire file, so add the extent
+			 * we got last time and exit.
+			 *
+			 * This is for the case where say we want to map all the
+			 * way up to the second to the last block in a file, but
+			 * the last block is a hole, making the second to last
+			 * block FIEMAP_EXTENT_LAST.  In this case we want to
+			 * see if there is a hole after the second to last block
+			 * so we can mark it properly.  If we found data after
+			 * we exceeded the length we were requesting, then we
+			 * are good to go, just add the extent to the fieinfo
+			 * and break
+			 */
+			if (start_blk > last_blk && !whole_file) {
+				ret = fiemap_fill_next_extent(fieinfo, logical,
+							      phys, size,
+							      flags);
+				break;
+			}
+
+			/*
+			 * if size != 0 then we know we already have an extent
+			 * to add, so add it.
+			 */
+			if (size) {
+				ret = fiemap_fill_next_extent(fieinfo, logical,
+							      phys, size,
+							      flags);
+				if (ret)
+					break;
+			}
+
+			logical = blk_to_logical(inode, start_blk);
+			phys = blk_to_logical(inode, map_bh.b_blocknr);
+			size = map_bh.b_size;
+			flags = FIEMAP_EXTENT_MERGED;
+
+			start_blk += logical_to_blk(inode, size);
+
+			/*
+			 * If we are past the EOF, then we need to make sure as
+			 * soon as we find a hole that the last extent we found
+			 * is marked with FIEMAP_EXTENT_LAST
+			 */
+			if (!past_eof && logical + size >= isize)
+				past_eof = true;
+		}
+		cond_resched();
+		if (fatal_signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+
+	} while (1);
+
+	/* If ret is 1 then we just hit the end of the extent array */
+	if (ret == 1)
+		ret = 0;
+
+	return ret;
+}
+EXPORT_SYMBOL(__generic_block_fiemap);
+
+/**
+ * generic_block_fiemap - FIEMAP for block based inodes
+ * @inode: The inode to map
+ * @fieinfo: The mapping information
+ * @start: The initial block to map
+ * @len: The length of the extect to attempt to map
+ * @get_block: The block mapping function for the fs
+ *
+ * Calls __generic_block_fiemap to map the inode, after taking
+ * the inode's mutex lock.
+ */
+
+int generic_block_fiemap(struct inode *inode,
+			 struct fiemap_extent_info *fieinfo, u64 start,
+			 u64 len, get_block_t *get_block)
+{
+	int ret;
+	mutex_lock(&inode->i_mutex);
+	ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
+	mutex_unlock(&inode->i_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(generic_block_fiemap);
+
+#endif  /*  CONFIG_BLOCK  */
+
+/*
+ * This provides compatibility with legacy XFS pre-allocation ioctls
+ * which predate the fallocate syscall.
+ *
+ * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
+ * are used here, rest are ignored.
+ */
+int ioctl_preallocate(struct file *filp, void __user *argp)
+{
+	struct inode *inode = file_inode(filp);
+	struct space_resv sr;
+
+	if (copy_from_user(&sr, argp, sizeof(sr)))
+		return -EFAULT;
+
+	switch (sr.l_whence) {
+	case SEEK_SET:
+		break;
+	case SEEK_CUR:
+		sr.l_start += filp->f_pos;
+		break;
+	case SEEK_END:
+		sr.l_start += i_size_read(inode);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return vfs_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
+}
+
+static int file_ioctl(struct file *filp, unsigned int cmd,
+		unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	int __user *p = (int __user *)arg;
+
+	switch (cmd) {
+	case FIBMAP:
+		return ioctl_fibmap(filp, p);
+	case FIONREAD:
+		return put_user(i_size_read(inode) - filp->f_pos, p);
+	case FS_IOC_RESVSP:
+	case FS_IOC_RESVSP64:
+		return ioctl_preallocate(filp, p);
+	}
+
+	return vfs_ioctl(filp, cmd, arg);
+}
+
+static int ioctl_fionbio(struct file *filp, int __user *argp)
+{
+	unsigned int flag;
+	int on, error;
+
+	error = get_user(on, argp);
+	if (error)
+		return error;
+	flag = O_NONBLOCK;
+#ifdef __sparc__
+	/* SunOS compatibility item. */
+	if (O_NONBLOCK != O_NDELAY)
+		flag |= O_NDELAY;
+#endif
+	spin_lock(&filp->f_lock);
+	if (on)
+		filp->f_flags |= flag;
+	else
+		filp->f_flags &= ~flag;
+	spin_unlock(&filp->f_lock);
+	return error;
+}
+
+static int ioctl_fioasync(unsigned int fd, struct file *filp,
+			  int __user *argp)
+{
+	unsigned int flag;
+	int on, error;
+
+	error = get_user(on, argp);
+	if (error)
+		return error;
+	flag = on ? FASYNC : 0;
+
+	/* Did FASYNC state change ? */
+	if ((flag ^ filp->f_flags) & FASYNC) {
+		if (filp->f_op->fasync)
+			/* fasync() adjusts filp->f_flags */
+			error = filp->f_op->fasync(fd, filp, on);
+		else
+			error = -ENOTTY;
+	}
+	return error < 0 ? error : 0;
+}
+
+static int ioctl_fsfreeze(struct file *filp)
+{
+	struct super_block *sb = file_inode(filp)->i_sb;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/* If filesystem doesn't support freeze feature, return. */
+	if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
+		return -EOPNOTSUPP;
+
+	/* Freeze */
+	if (sb->s_op->freeze_super)
+		return sb->s_op->freeze_super(sb);
+	return freeze_super(sb);
+}
+
+static int ioctl_fsthaw(struct file *filp)
+{
+	struct super_block *sb = file_inode(filp)->i_sb;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/* Thaw */
+	if (sb->s_op->thaw_super)
+		return sb->s_op->thaw_super(sb);
+	return thaw_super(sb);
+}
+
+/*
+ * When you add any new common ioctls to the switches above and below
+ * please update compat_sys_ioctl() too.
+ *
+ * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
+ * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
+ */
+int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
+	     unsigned long arg)
+{
+	int error = 0;
+	int __user *argp = (int __user *)arg;
+	struct inode *inode = file_inode(filp);
+
+	switch (cmd) {
+	case FIOCLEX:
+		set_close_on_exec(fd, 1);
+		break;
+
+	case FIONCLEX:
+		set_close_on_exec(fd, 0);
+		break;
+
+	case FIONBIO:
+		error = ioctl_fionbio(filp, argp);
+		break;
+
+	case FIOASYNC:
+		error = ioctl_fioasync(fd, filp, argp);
+		break;
+
+	case FIOQSIZE:
+		if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
+		    S_ISLNK(inode->i_mode)) {
+			loff_t res = inode_get_bytes(inode);
+			error = copy_to_user(argp, &res, sizeof(res)) ?
+					-EFAULT : 0;
+		} else
+			error = -ENOTTY;
+		break;
+
+	case FIFREEZE:
+		error = ioctl_fsfreeze(filp);
+		break;
+
+	case FITHAW:
+		error = ioctl_fsthaw(filp);
+		break;
+
+	case FS_IOC_FIEMAP:
+		return ioctl_fiemap(filp, arg);
+
+	case FIGETBSZ:
+		return put_user(inode->i_sb->s_blocksize, argp);
+
+	default:
+		if (S_ISREG(inode->i_mode))
+			error = file_ioctl(filp, cmd, arg);
+		else
+			error = vfs_ioctl(filp, cmd, arg);
+		break;
+	}
+	return error;
+}
+
+SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
+{
+	int error;
+	struct fd f = fdget(fd);
+
+	if (!f.file)
+		return -EBADF;
+	error = security_file_ioctl(f.file, cmd, arg);
+	if (!error)
+		error = do_vfs_ioctl(f.file, fd, cmd, arg);
+	fdput(f);
+	return error;
+}