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ceph: fix short synchronous reads

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Zeroing of holes was not done correctly: page_off was miscalculated and
zeroing the tail didn't not adjust the 'read' value to include the zeroed
portion.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Yehuda Sadeh 2010-02-04 13:41:41 -08:00 committed by Sage Weil
parent 02f90c6109
commit 972f0d3ab1
1 changed files with 9 additions and 9 deletions
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18
fs/ceph/file.c
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@ -395,23 +395,22 @@ static void zero_page_vector_range(int off, int len, struct page **pages)
{
int i = off >> PAGE_CACHE_SHIFT;
off &= ~PAGE_CACHE_MASK;
dout("zero_page_vector_page %u~%u\n", off, len);
BUG_ON(len < PAGE_CACHE_SIZE);
/* leading partial page? */
if (off & ~PAGE_CACHE_MASK) {
if (off) {
int end = min((int)PAGE_CACHE_SIZE, off + len);
dout("zeroing %d %p head from %d\n", i, pages[i],
(int)(off & ~PAGE_CACHE_MASK));
zero_user_segment(pages[i], off & ~PAGE_CACHE_MASK,
PAGE_CACHE_SIZE);
off += PAGE_CACHE_SIZE;
off &= PAGE_CACHE_MASK;
(int)off);
zero_user_segment(pages[i], off, end);
len -= (end - off);
i++;
}
while (len >= PAGE_CACHE_SIZE) {
dout("zeroing %d %p\n", i, pages[i]);
zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
off += PAGE_CACHE_SIZE;
len -= PAGE_CACHE_SIZE;
i++;
}
@ -437,7 +436,7 @@ static int striped_read(struct inode *inode,
struct ceph_client *client = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
u64 pos, this_len;
int page_off = off & ~PAGE_CACHE_SIZE; /* first byte's offset in page */
int page_off = off & ~PAGE_CACHE_MASK; /* first byte's offset in page */
int left, pages_left;
int read;
struct page **page_pos;
@ -493,6 +492,7 @@ more:
dout("zero tail\n");
zero_page_vector_range(page_off + read, len - read,
pages);
read = len;
goto out;
}