args.src_length, args.dest_offset);
}
-#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.
- */
-static 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_prep(inode, fieinfo, start, &len, 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;
-}
-
-/**
- * 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;
- inode_lock(inode);
- ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
- inode_unlock(inode);
- return ret;
-}
-EXPORT_SYMBOL(generic_block_fiemap);
-
-#endif /* CONFIG_BLOCK */
-
/*
* This provides compatibility with legacy XFS pre-allocation ioctls
* which predate the fallocate syscall.
projects / linux-2.6-microblaze.git / blobdiff