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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /fs/ioctl.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'fs/ioctl.c')
-rw-r--r-- | fs/ioctl.c | 623 |
1 files changed, 623 insertions, 0 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c new file mode 100644 index 00000000..1d9b9fcb --- /dev/null +++ b/fs/ioctl.c @@ -0,0 +1,623 @@ +/* + * 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/module.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 || !filp->f_op->unlocked_ioctl) + goto out; + + error = filp->f_op->unlocked_ioctl(filp, cmd, arg); + if (error == -ENOIOCTLCMD) + error = -EINVAL; + 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 = filp->f_path.dentry->d_inode; + 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(); + } 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 = filp->f_path.dentry->d_inode; + 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 do_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 = filp->f_path.dentry->d_inode; + 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 && 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; +} |