From c47d7a51ef654c83883046630e1d47e42228ba7b Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 20 Jul 2011 08:43:41 +1000 Subject: [PATCH] xfstests: fix modulo-by-zero error in fsx The recent fsx fixes has a logic error in the offset trimming code. If a read is done when the file size is zero, then the logic error causes a offset % 0 opertaion to occur. This causes fsx to get a SIGFPE and die. This was not discovered during my testing because I was using a random seed that didn't trip this condition. Changing the seed to that which test 091 uses (the default of 1) causes such an operation to occur.... Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- ltp/fsx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/ltp/fsx.c b/ltp/fsx.c index 771bcdc0a..d53c49801 100644 --- a/ltp/fsx.c +++ b/ltp/fsx.c @@ -987,14 +987,14 @@ docloseopen(void) } } -#define TRIM_OFF_LEN(off, len, size, zero_offset) \ -do { \ - if (!zero_offset || file_size) \ - offset %= size; \ - else \ - offset = 0; \ - if (offset + len > size) \ - len = size - offset; \ +#define TRIM_OFF_LEN(off, len, size, allow_zero_file_size) \ +do { \ + if (allow_zero_file_size || file_size) \ + offset %= size; \ + else \ + offset = 0; \ + if (offset + len > size) \ + len = size - offset; \ } while (0) void