GFS2: Fix direct IO write rounding error
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PATCH 1/1 GFS2: Fix direct IO write rounding error
Hi,
The fsx test in xfstests was failing because it was using direct IO writes which were using a bad calculation. It was using loff_t lstart = offset & (PAGE_CACHE_SIZE - 1); when it should be loff_t lstart = offset & ~(PAGE_CACHE_SIZE - 1);
Thus, the write at offset 0x67e00 was calculating lstart to be 0xe00, the address of our corruption. Instead, it should have been 0x67000. This patch fixes the calculation.
Regards,
Bob Peterson
Red Hat File Systems
---
fs/gfs2/aops.c +1 -1
@@ -1082,7 +1082,7 @@ static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter,* the first place, mapping->nr_pages will always be zero. */ if (mapping->nrpages) { -loff_t lstart = offset & (PAGE_CACHE_SIZE -1 ); +loff_t lstart = offset & ~(PAGE_CACHE_SIZE -1 );loff_t len =iov_iter_count (iter);loff_t end =PAGE_ALIGN (offset + len) -1 ;
PATCH 1/1 GFS2: Fix direct IO write rounding error
Hi,
Quoted 10 lines · Bob Peterson
Hi,
The fsx test in xfstests was failing because it was using direct IO writes which were using a bad calculation. It was using
loff_tlstart = offset & (PAGE_CACHE_SIZE- 1); when it should beloff_tlstart = offset & ~(PAGE_CACHE_SIZE - 1);
Thus, the write at offset0x67e00was calculating lstart to be0xe00, the address of our corruption. Instead, it should have been0x67000. This patch fixes the calculation.
Quoted 6 lines
Regards,
Bob Peterson
Red Hat File SystemsSigned-off-by Bob Peterson <[email protected]>
Steve.
Quoted 15 lines
---
fs/gfs2/aops.c +1
-1@@ -1082,7 +1082,7 @@ static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter,* the first place, mapping->nr_pages will always be zero. */ if (mapping->nrpages) { -loff_t lstart = offset & (PAGE_CACHE_SIZE -1 ); +loff_t lstart = offset & ~(PAGE_CACHE_SIZE -1 );loff_t len =iov_iter_count (iter);loff_t end =PAGE_ALIGN (offset + len) -1 ;