[dm-devel] multipath-tools sector size bug

[John Kingman]

Hello,

I encountered a problem with the sg_read() routine in readsector0.c
while testing an InfiniBand target having 4096 byte sectors.  The
sg_read() routine assumes that sectors are 512 bytes long.

A patch for the problem follows.

John Kingman

--- readsector0.c.orig	2006-03-13 05:07:45.000000000 -0600
+++ readsector0.c	2007-07-03 14:20:14.000000000 -0500
@@ -51,7 +51,11 @@
 	int res;
 	int rd_opcode[] = {0x8, 0x28, 0xa8, 0x88};
 	int sz_ind;
-	
+	struct stat filestatus;
+
+	if (fstat(sg_fd, &filestatus) != 0) 
+		return PATH_DOWN;
+	bs = (filestatus.st_blksize > 4096)? 4096: filestatus.st_blksize;
 	memset(rdCmd, 0, cdbsz);
 	sz_ind = 1;
 	rdCmd[0] = rd_opcode[sz_ind];
@@ -97,7 +101,7 @@
 extern int
 readsector0 (struct checker * c)
 {
-	unsigned char buf[512];
+	unsigned char buf[4096];
 	int ret;
 
 	ret = sg_read(c->fd, &buf[0]);