iomap: fix integer truncation issues in the zeroing and dirtying helpers (e28ae8e4) · Commits · 戴 / test

Fix the min_t calls in the zeroing and dirtying helpers to perform the comparisms on 64-bit types, which prevents them from incorrectly being truncated, and larger zeroing operations being stuck in a never ending loop. Special thanks to Markus Stockhausen for spotting the bug. Reported-by:

Paul Menzel <pmenzel@molgen.mpg.de> Tested-by:

Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by:

Christoph Hellwig <hch@lst.de> Reviewed-by:

Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by:

Darrick J. Wong <darrick.wong@oracle.com>

fs/iomap.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -278,7 +278,7 @@ iomap_dirty_actor(struct inode inode, loff_t pos, loff_t length, void data,
		unsigned long bytes; /* Bytes to write to page */

		offset = (pos & (PAGE_SIZE - 1));
		bytes = min_t(unsigned long, PAGE_SIZE - offset, length);
		bytes = min_t(loff_t, PAGE_SIZE - offset, length);

		rpage = __iomap_read_page(inode, pos);
		if (IS_ERR(rpage))
		@@ -373,7 +373,7 @@ iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
		unsigned offset, bytes;

		offset = pos & (PAGE_SIZE - 1); /* Within page */
		bytes = min_t(unsigned, PAGE_SIZE - offset, count);
		bytes = min_t(loff_t, PAGE_SIZE - offset, count);

		if (IS_DAX(inode))
		status = iomap_dax_zero(pos, offset, bytes, iomap);

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