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