From d8de9ab63a57326d21154c13c365f949f53ce8e1 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 26 Jul 2011 11:27:34 -0700 Subject: ceph: avoid carrying Fw cap during write into page cache The generic_file_aio_write call may block on balance_dirty_pages while we flush data to the OSDs. If we hold a reference to the FILE_WR cap during that interval revocation by the MDS (e.g., to do a stat(2)) may be very slow. Reviewed-by: Yehuda Sadeh Signed-off-by: Sage Weil --- fs/ceph/file.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 44e4fe9fba02..6c90cf090601 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -713,7 +713,7 @@ retry_snap: want = CEPH_CAP_FILE_BUFFER; ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, endoff); if (ret < 0) - goto out; + goto out_put; dout("aio_write %p %llx.%llx %llu~%u got cap refs on %s\n", inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len, @@ -726,8 +726,18 @@ retry_snap: ret = ceph_sync_write(file, iov->iov_base, iov->iov_len, &iocb->ki_pos); } else { - ret = generic_file_aio_write(iocb, iov, nr_segs, pos); + /* + * buffered write; drop Fw early to avoid slow + * revocation if we get stuck on balance_dirty_pages + */ + int dirty; + + spin_lock(&inode->i_lock); + dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR); + spin_unlock(&inode->i_lock); + ceph_put_cap_refs(ci, got); + ret = generic_file_aio_write(iocb, iov, nr_segs, pos); if ((ret >= 0 || ret == -EIOCBQUEUED) && ((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host) || ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) { @@ -735,7 +745,12 @@ retry_snap: if (err < 0) ret = err; } + + if (dirty) + __mark_inode_dirty(inode, dirty); + goto out; } + if (ret >= 0) { int dirty; spin_lock(&inode->i_lock); @@ -745,12 +760,13 @@ retry_snap: __mark_inode_dirty(inode, dirty); } -out: +out_put: dout("aio_write %p %llx.%llx %llu~%u dropping cap refs on %s\n", inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len, ceph_cap_string(got)); ceph_put_cap_refs(ci, got); +out: if (ret == -EOLDSNAPC) { dout("aio_write %p %llx.%llx %llu~%u got EOLDSNAPC, retrying\n", inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len); -- cgit v1.2.3-59-g8ed1b