fiemap: fix problem with setting FIEMAP_EXTENT_LAST (df3935ff) · Commits · 戴 / test

fs/ioctl.c

+55 −20

Original line number	Diff line number	Diff line
		@@ -258,7 +258,7 @@ int __generic_block_fiemap(struct inode *inode,
		long long length = 0, map_len = 0;
		u64 logical = 0, phys = 0, size = 0;
		u32 flags = FIEMAP_EXTENT_MERGED;
		int ret = 0;
		int ret = 0, past_eof = 0, whole_file = 0;

		if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC)))
		return ret;
		@@ -266,6 +266,9 @@ int __generic_block_fiemap(struct inode *inode,
		start_blk = logical_to_blk(inode, start);

		length = (long long)min_t(u64, len, i_size_read(inode));
		if (length < len)
		whole_file = 1;

		map_len = length;

		do {
		@@ -282,11 +285,26 @@ int __generic_block_fiemap(struct inode *inode,

		/* HOLE */
		if (!buffer_mapped(&tmp)) {
		length -= blk_to_logical(inode, 1);
		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) >=
		blk_to_logical(inode, 0)+i_size_read(inode))
		past_eof = 1;

		/*
		* first hole after going past the EOF, this is our
		* last extent
		*/
		if (length <= 0) {
		if (past_eof && size) {
		flags = FIEMAP_EXTENT_MERGED\|FIEMAP_EXTENT_LAST;
		ret = fiemap_fill_next_extent(fieinfo, logical,
		phys, size,
		@@ -294,15 +312,37 @@ int __generic_block_fiemap(struct inode *inode,
		break;
		}

		length -= blk_to_logical(inode, 1);

		/* if we have holes up to/past EOF then we're done */
		if (length <= 0)
		if (length <= 0 \|\| past_eof)
		break;

		start_blk++;
		} else {
		if (length <= 0 && size) {
		/*
		* 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 (length <= 0 && !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);
		@@ -319,19 +359,14 @@ int __generic_block_fiemap(struct inode *inode,
		start_blk += logical_to_blk(inode, size);

		/*
		* if we are past the EOF we need to loop again to see
		* if there is a hole so we can mark this extent as the
		* last one, and if not keep mapping things until we
		* find a hole, or we run out of slots in the extent
		* array
		* 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 (length <= 0)
		continue;

		ret = fiemap_fill_next_extent(fieinfo, logical, phys,
		size, flags);
		if (ret)
		break;
		if (!past_eof &&
		logical+size >=
		blk_to_logical(inode, 0)+i_size_read(inode))
		past_eof = 1;
		}
		cond_resched();
		} while (1);

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