ceph: perform lazy reads when file mode and caps permit
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>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 85c86ed5..2329244 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -740,28 +740,32 @@
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... */