afs: Make some RPC operations non-interruptible

Make certain RPC operations non-interruptible, including:

 (*) Set attributes
 (*) Store data

     We don't want to get interrupted during a flush on close, flush on
     unlock, writeback or an inode update, leaving us in a state where we
     still need to do the writeback or update.

 (*) Extend lock
 (*) Release lock

     We don't want to get lock extension interrupted as the file locks on
     the server are time-limited.  Interruption during lock release is less
     of an issue since the lock is time-limited, but it's better to
     complete the release to avoid a several-minute wait to recover it.

     *Setting* the lock isn't a problem if it's interrupted since we can
      just return to the user and tell them they were interrupted - at
      which point they can elect to retry.

 (*) Silly unlink

     We want to remove silly unlink files if we can, rather than leaving
     them for the salvager to clear up.

Note that whilst these calls are no longer interruptible, they do have
timeouts on them, so if the server stops responding the call will fail with
something like ETIME or ECONNRESET.

Without this, the following:

	kAFS: Unexpected error from FS.StoreData -512

appears in dmesg when a pending store data gets interrupted and some
processes may just hang.

Additionally, make the code that checks/updates the server record ignore
failure due to interruption if the main call is uninterruptible and if the
server has an address list.  The next op will check it again since the
expiration time on the old list has past.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 9a466be583d2..c15550310f62 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -704,7 +704,7 @@ static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
 		goto no_inline_bulk_status;
 
 	inode = ERR_PTR(-ERESTARTSYS);
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			if (test_bit(AFS_SERVER_FL_NO_IBULK,
 				      &fc.cbi->server->flags)) {
@@ -739,7 +739,7 @@ no_inline_bulk_status:
 	 */
 	cookie->nr_fids = 1;
 	inode = ERR_PTR(-ERESTARTSYS);
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			afs_fs_fetch_status(&fc,
 					    afs_v2net(dvnode),
@@ -1166,7 +1166,7 @@ static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
@@ -1250,7 +1250,7 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_remove(&fc, vnode, dentry->d_name.name, true,
@@ -1374,7 +1374,7 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
 	spin_unlock(&dentry->d_lock);
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 
@@ -1445,7 +1445,7 @@ static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
@@ -1510,7 +1510,7 @@ static int afs_link(struct dentry *from, struct inode *dir,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		if (mutex_lock_interruptible_nested(&vnode->io_lock, 1) < 0) {
 			afs_end_vnode_operation(&fc);
 			goto error_key;
@@ -1584,7 +1584,7 @@ static int afs_symlink(struct inode *dir, struct dentry *dentry,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
 			afs_fs_symlink(&fc, dentry->d_name.name,
@@ -1696,7 +1696,7 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 
 	ret = -ERESTARTSYS;
-	if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) {
+	if (afs_begin_vnode_operation(&fc, orig_dvnode, key, true)) {
 		if (orig_dvnode != new_dvnode) {
 			if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
 				afs_end_vnode_operation(&fc);