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-rw-r--r--fs/ioctl.c625
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;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-18 04:11:26 +0000