mmc: s3c6410: enable ADMA feature in 6410 sdhci controller
[safe/jmp/linux-2.6] / fs / ioctl.c
index 652cacf..2d140a7 100644 (file)
 #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>
 
-static long do_ioctl(struct file *filp, unsigned int cmd,
-               unsigned long arg)
+/* 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
+ * invokes filesystem specific ->ioctl method.  If neither method exists,
+ * 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;
 
@@ -40,53 +58,500 @@ static long do_ioctl(struct file *filp, unsigned int cmd,
        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 *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_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, (struct fiemap __user *)arg,
+                          sizeof(struct 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 = (struct fiemap_extent *)(arg + sizeof(fiemap));
+
+       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((char *)arg, &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;
+       }
+
+       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)
 {
-       int error;
-       int block;
        struct inode *inode = filp->f_path.dentry->d_inode;
        int __user *p = (int __user *)arg;
 
        switch (cmd) {
        case FIBMAP:
-       {
-               struct address_space *mapping = filp->f_mapping;
-               int res;
-               /* do we support this mess? */
-               if (!mapping->a_ops->bmap)
-                       return -EINVAL;
-               if (!capable(CAP_SYS_RAWIO))
-                       return -EPERM;
-               error = get_user(block, p);
-               if (error)
-                       return error;
-               lock_kernel();
-               res = mapping->a_ops->bmap(mapping, block);
-               unlock_kernel();
-               return put_user(res, p);
-       }
-       case FIGETBSZ:
-               return put_user(inode->i_sb->s_blocksize, p);
+               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 do_ioctl(filp, cmd, arg);
+       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.
  *
- * vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
+ * 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 vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
-             unsigned long arg)
+int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
+            unsigned long arg)
 {
-       unsigned int flag;
-       int on, error = 0;
+       int error = 0;
+       int __user *argp = (int __user *)arg;
 
        switch (cmd) {
        case FIOCLEX:
@@ -98,43 +563,11 @@ int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
                break;
 
        case FIONBIO:
-               error = get_user(on, (int __user *)arg);
-               if (error)
-                       break;
-               flag = O_NONBLOCK;
-#ifdef __sparc__
-               /* SunOS compatibility item. */
-               if (O_NONBLOCK != O_NDELAY)
-                       flag |= O_NDELAY;
-#endif
-               if (on)
-                       filp->f_flags |= flag;
-               else
-                       filp->f_flags &= ~flag;
+               error = ioctl_fionbio(filp, argp);
                break;
 
        case FIOASYNC:
-               error = get_user(on, (int __user *)arg);
-               if (error)
-                       break;
-               flag = on ? FASYNC : 0;
-
-               /* Did FASYNC state change ? */
-               if ((flag ^ filp->f_flags) & FASYNC) {
-                       if (filp->f_op && filp->f_op->fasync) {
-                               lock_kernel();
-                               error = filp->f_op->fasync(fd, filp, on);
-                               unlock_kernel();
-                       } else
-                               error = -ENOTTY;
-               }
-               if (error != 0)
-                       break;
-
-               if (on)
-                       filp->f_flags |= FASYNC;
-               else
-                       filp->f_flags &= ~FASYNC;
+               error = ioctl_fioasync(fd, filp, argp);
                break;
 
        case FIOQSIZE:
@@ -148,17 +581,36 @@ int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
                } 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:
+       {
+               struct inode *inode = filp->f_path.dentry->d_inode;
+               int __user *p = (int __user *)arg;
+               return put_user(inode->i_sb->s_blocksize, p);
+       }
+
        default:
                if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
                        error = file_ioctl(filp, cmd, arg);
                else
-                       error = do_ioctl(filp, cmd, arg);
+                       error = vfs_ioctl(filp, cmd, arg);
                break;
        }
        return error;
 }
 
-asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
+SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
 {
        struct file *filp;
        int error = -EBADF;
@@ -172,7 +624,7 @@ asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
        if (error)
                goto out_fput;
 
-       error = vfs_ioctl(filp, fd, cmd, arg);
+       error = do_vfs_ioctl(filp, fd, cmd, arg);
  out_fput:
        fput_light(filp, fput_needed);
  out: