fs/adfs: map: fix map scanning (f93793fd) · Commits · 戴 / test

When scanning the map for a fragment id, we need to keep track of the free space links, so we don't inadvertently believe that the freespace link is a valid fragment id. Signed-off-by:

Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by:

Al Viro <viro@zeniv.linux.org.uk>

fs/adfs/map.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -72,9 +72,12 @@ static int lookup_zone(const struct adfs_discmap *dm, const unsigned int idlen,
		const u32 idmask = (1 << idlen) - 1;
		unsigned char *map = dm->dm_bh->b_data;
		unsigned int start = dm->dm_startbit;
		unsigned int fragend;
		unsigned int freelink, fragend;
		u32 frag;

		frag = GET_FRAG_ID(map, 8, idmask & 0x7fff);
		freelink = frag ? 8 + frag : 0;

		do {
		frag = GET_FRAG_ID(map, start, idmask);

		@@ -82,7 +85,9 @@ static int lookup_zone(const struct adfs_discmap *dm, const unsigned int idlen,
		if (fragend >= endbit)
		goto error;

		if (frag == frag_id) {
		if (start == freelink) {
		freelink += frag & 0x7fff;
		} else if (frag == frag_id) {
		unsigned int length = fragend + 1 - start;

		if (*offset < length)

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