From: Yan, Zheng <zyan@redhat.com>
Date: Wed, 18 May 2016 12:58:26 +0000 (+0800)
Subject: ceph: don't use truncate_pagecache() to invalidate read cache
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9abd4db713704aac146395e079224ddd716e9b95;p=linux.git

ceph: don't use truncate_pagecache() to invalidate read cache

truncate_pagecache() drops dirty pages, it's dangerous to use it
to invalidate read cache. Besides, we shouldn't start invalidating
read cache while there are buffer writers. Because buffer writers
may add dirty pages later.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
---

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index fab93c66d879f..c17b5d76d75ee 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1656,7 +1656,7 @@ retry_locked:
 	 */
 	if ((!is_delayed || mdsc->stopping) &&
 	    !S_ISDIR(inode->i_mode) &&		/* ignore readdir cache */
-	    ci->i_wrbuffer_ref == 0 &&		/* no dirty pages... */
+	    !(ci->i_wb_ref || ci->i_wrbuffer_ref) &&   /* no dirty pages... */
 	    inode->i_data.nrpages &&		/* have cached pages */
 	    (revoking & (CEPH_CAP_FILE_CACHE|
 			 CEPH_CAP_FILE_LAZYIO)) && /*  or revoking cache */
@@ -1698,8 +1698,8 @@ retry_locked:
 
 		revoking = cap->implemented & ~cap->issued;
 		dout(" mds%d cap %p used %s issued %s implemented %s revoking %s\n",
-		     cap->mds, cap, ceph_cap_string(cap->issued),
-		     ceph_cap_string(cap_used),
+		     cap->mds, cap, ceph_cap_string(cap_used),
+		     ceph_cap_string(cap->issued),
 		     ceph_cap_string(cap->implemented),
 		     ceph_cap_string(revoking));
 
@@ -2828,7 +2828,7 @@ static void handle_cap_grant(struct ceph_mds_client *mdsc,
 	if (!S_ISDIR(inode->i_mode) && /* don't invalidate readdir cache */
 	    ((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
 	    (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
-	    !ci->i_wrbuffer_ref) {
+	    !(ci->i_wrbuffer_ref || ci->i_wb_ref)) {
 		if (try_nonblocking_invalidate(inode)) {
 			/* there were locked pages.. invalidate later
 			   in a separate thread. */
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 89d08155986df..07495ba61fe3d 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1728,7 +1728,9 @@ static void ceph_invalidate_work(struct work_struct *work)
 	orig_gen = ci->i_rdcache_gen;
 	spin_unlock(&ci->i_ceph_lock);
 
-	truncate_pagecache(inode, 0);
+	if (invalidate_inode_pages2(inode->i_mapping) < 0) {
+		pr_err("invalidate_pages %p fails\n", inode);
+	}
 
 	spin_lock(&ci->i_ceph_lock);
 	if (orig_gen == ci->i_rdcache_gen &&