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| author | Sage Weil <sage@newdream.net> | 2011-07-26 22:27:34 +0400 |
|---|---|---|
| committer | Sage Weil <sage@newdream.net> | 2011-07-26 22:27:34 +0400 |
| commit | d8de9ab63a57326d21154c13c365f949f53ce8e1 (patch) | |
| tree | 283aac6bf2cc91a772d9cc04c97f46f60267e4c5 | |
| parent | 4cf9d544631c92809cb94ea680c71df56e9437aa (diff) | |
| download | linux-d8de9ab63a57326d21154c13c365f949f53ce8e1.tar.xz | |
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 <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
| -rw-r--r-- | fs/ceph/file.c | 22 |
1 files changed, 19 insertions, 3 deletions
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); |