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ceph: perform lazy reads when file mode and caps permit

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If the file mode is marked as "lazy," perform cached/buffered reads when
the caps permit it.  Adjust the rdcache_gen and invalidation logic
accordingly so that we manage our cache based on the FILE_CACHE -or-
FILE_LAZYIO cap bits.

Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Sage Weil 2010-05-27 10:40:43 -07:00
parent 33caad324b
commit 2962507ca2
4 changed files with 22 additions and 13 deletions
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2
fs/ceph/addr.c
View File

@ -552,7 +552,7 @@ static void writepages_finish(struct ceph_osd_request *req,
* page truncation thread, possibly losing some data that
* raced its way in
*/
if ((issued & CEPH_CAP_FILE_CACHE) == 0)
if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
generic_error_remove_page(inode->i_mapping, page);
unlock_page(page);

16
fs/ceph/caps.c
View File

@ -482,8 +482,8 @@ static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
* Each time we receive FILE_CACHE anew, we increment
* i_rdcache_gen.
*/
if ((issued & CEPH_CAP_FILE_CACHE) &&
(had & CEPH_CAP_FILE_CACHE) == 0)
if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
(had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
ci->i_rdcache_gen++;
/*
@ -1509,11 +1509,13 @@ retry_locked:
ci->i_wrbuffer_ref == 0 && /* no dirty pages... */
ci->i_rdcache_gen && /* may have cached pages */
(file_wanted == 0 || /* no open files */
(revoking & CEPH_CAP_FILE_CACHE)) && /* or revoking cache */
(revoking & (CEPH_CAP_FILE_CACHE|
CEPH_CAP_FILE_LAZYIO))) && /* or revoking cache */
!tried_invalidate) {
dout("check_caps trying to invalidate on %p\n", inode);
if (try_nonblocking_invalidate(inode) < 0) {
if (revoking & CEPH_CAP_FILE_CACHE) {
if (revoking & (CEPH_CAP_FILE_CACHE|
CEPH_CAP_FILE_LAZYIO)) {
dout("check_caps queuing invalidate\n");
queue_invalidate = 1;
ci->i_rdcache_revoking = ci->i_rdcache_gen;
@ -2276,7 +2278,8 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
* try to invalidate (once). (If there are dirty buffers, we
* will invalidate _after_ writeback.)
*/
if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
if (((cap->issued & ~newcaps) & (CEPH_CAP_FILE_CACHE|
CEPH_CAP_FILE_LAZYIO)) &&
!ci->i_wrbuffer_ref) {
if (try_nonblocking_invalidate(inode) == 0) {
revoked_rdcache = 1;
@ -2374,7 +2377,8 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
writeback = 1; /* will delay ack */
else if (dirty & ~newcaps)
check_caps = 1; /* initiate writeback in check_caps */
else if (((used & ~newcaps) & CEPH_CAP_FILE_CACHE) == 0 ||
else if (((used & ~newcaps) & (CEPH_CAP_FILE_CACHE|
CEPH_CAP_FILE_LAZYIO)) == 0 ||
revoked_rdcache)
check_caps = 2; /* send revoke ack in check_caps */
cap->issued = newcaps;

12
fs/ceph/file.c
View File

@ -740,28 +740,32 @@ static ssize_t ceph_aio_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct file *filp = iocb->ki_filp;
struct ceph_file_info *fi = filp->private_data;
loff_t *ppos = &iocb->ki_pos;
size_t len = iov->iov_len;
struct inode *inode = filp->f_dentry->d_inode;
struct ceph_inode_info *ci = ceph_inode(inode);
void *base = iov->iov_base;
ssize_t ret;
int got = 0;
int want, got = 0;
int checkeof = 0, read = 0;
dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
inode, ceph_vinop(inode), pos, (unsigned)len, inode);
again:
__ceph_do_pending_vmtruncate(inode);
ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, CEPH_CAP_FILE_CACHE,
&got, -1);
if (fi->fmode & CEPH_FILE_MODE_LAZY)
want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
else
want = CEPH_CAP_FILE_CACHE;
ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, &got, -1);
if (ret < 0)
goto out;
dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
inode, ceph_vinop(inode), pos, (unsigned)len,
ceph_cap_string(got));
if ((got & CEPH_CAP_FILE_CACHE) == 0 ||
if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
(iocb->ki_filp->f_flags & O_DIRECT) ||
(inode->i_sb->s_flags & MS_SYNCHRONOUS))
/* hmm, this isn't really async... */

5
fs/ceph/inode.c
View File

@ -442,8 +442,9 @@ int ceph_fill_file_size(struct inode *inode, int issued,
* the file is either opened or mmaped
*/
if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_RD|
CEPH_CAP_FILE_WR|CEPH_CAP_FILE_BUFFER|
CEPH_CAP_FILE_EXCL)) ||
CEPH_CAP_FILE_WR|CEPH_CAP_FILE_BUFFER|
CEPH_CAP_FILE_EXCL|
CEPH_CAP_FILE_LAZYIO)) ||
mapping_mapped(inode->i_mapping) ||
__ceph_caps_file_wanted(ci)) {
ci->i_truncate_pending++;