summaryrefslogtreecommitdiff
path: root/fs/afs/dir_silly.c
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2019-05-09 15:16:10 +0100
committerDavid Howells <dhowells@redhat.com>2019-05-16 16:25:21 +0100
commita58823ac458968f9fb3dbf97ee2749a62be12807 (patch)
tree97a455815d4ff7da8b946704604fe63aa1836b14 /fs/afs/dir_silly.c
parent4571577f16c82f8db8133b228cdca5fd61042c77 (diff)
downloadlinux-sh-a58823ac458968f9fb3dbf97ee2749a62be12807.tar.gz
afs: Fix application of status and callback to be under same lock
When applying the status and callback in the response of an operation, apply them in the same critical section so that there's no race between checking the callback state and checking status-dependent state (such as the data version). Fix this by: (1) Allocating a joint {status,callback} record (afs_status_cb) before calling the RPC function for each vnode for which the RPC reply contains a status or a status plus a callback. A flag is set in the record to indicate if a callback was actually received. (2) These records are passed into the RPC functions to be filled in. The afs_decode_status() and yfs_decode_status() functions are removed and the cb_lock is no longer taken. (3) xdr_decode_AFSFetchStatus() and xdr_decode_YFSFetchStatus() no longer update the vnode. (4) xdr_decode_AFSCallBack() and xdr_decode_YFSCallBack() no longer update the vnode. (5) vnodes, expected data-version numbers and callback break counters (cb_break) no longer need to be passed to the reply delivery functions. Note that, for the moment, the file locking functions still need access to both the call and the vnode at the same time. (6) afs_vnode_commit_status() is now given the cb_break value and the expected data_version and the task of applying the status and the callback to the vnode are now done here. This is done under a single taking of vnode->cb_lock. (7) afs_pages_written_back() is now called by afs_store_data() rather than by the reply delivery function. afs_pages_written_back() has been moved to before the call point and is now given the first and last page numbers rather than a pointer to the call. (8) The indicator from YFS.RemoveFile2 as to whether the target file actually got removed (status.abort_code == VNOVNODE) rather than merely dropping a link is now checked in afs_unlink rather than in xdr_decode_YFSFetchStatus(). Supplementary fixes: (*) afs_cache_permit() now gets the caller_access mask from the afs_status_cb object rather than picking it out of the vnode's status record. afs_fetch_status() returns caller_access through its argument list for this purpose also. (*) afs_inode_init_from_status() now uses a write lock on cb_lock rather than a read lock and now sets the callback inside the same critical section. Fixes: c435ee34551e ("afs: Overhaul the callback handling") Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs/dir_silly.c')
-rw-r--r--fs/afs/dir_silly.c31
1 files changed, 23 insertions, 8 deletions
diff --git a/fs/afs/dir_silly.c b/fs/afs/dir_silly.c
index fbc2d301ffe8..28f4aa015229 100644
--- a/fs/afs/dir_silly.c
+++ b/fs/afs/dir_silly.c
@@ -24,21 +24,28 @@ static int afs_do_silly_rename(struct afs_vnode *dvnode, struct afs_vnode *vnode
struct key *key)
{
struct afs_fs_cursor fc;
- u64 dir_data_version = dvnode->status.data_version;
+ struct afs_status_cb *scb;
int ret = -ERESTARTSYS;
_enter("%pd,%pd", old, new);
+ scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
+ if (!scb)
+ return -ENOMEM;
+
trace_afs_silly_rename(vnode, false);
if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
+ afs_dataversion_t dir_data_version = dvnode->status.data_version + 1;
+
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
afs_fs_rename(&fc, old->d_name.name,
dvnode, new->d_name.name,
- dir_data_version, dir_data_version);
+ scb, scb);
}
- afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
+ afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
+ &dir_data_version, scb);
ret = afs_end_vnode_operation(&fc);
}
@@ -64,6 +71,7 @@ static int afs_do_silly_rename(struct afs_vnode *dvnode, struct afs_vnode *vnode
fsnotify_nameremove(old, 0);
}
+ kfree(scb);
_leave(" = %d", ret);
return ret;
}
@@ -143,31 +151,37 @@ static int afs_do_silly_unlink(struct afs_vnode *dvnode, struct afs_vnode *vnode
struct dentry *dentry, struct key *key)
{
struct afs_fs_cursor fc;
- u64 dir_data_version = dvnode->status.data_version;
+ struct afs_status_cb *scb;
int ret = -ERESTARTSYS;
_enter("");
+ scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
+ if (!scb)
+ return -ENOMEM;
+
trace_afs_silly_rename(vnode, true);
if (afs_begin_vnode_operation(&fc, dvnode, key, false)) {
+ afs_dataversion_t dir_data_version = dvnode->status.data_version + 1;
+
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(dvnode);
if (test_bit(AFS_SERVER_FL_IS_YFS, &fc.cbi->server->flags) &&
!test_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags)) {
yfs_fs_remove_file2(&fc, vnode, dentry->d_name.name,
- dir_data_version);
+ &scb[0], &scb[1]);
if (fc.ac.error != -ECONNABORTED ||
fc.ac.abort_code != RXGEN_OPCODE)
continue;
set_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags);
}
- afs_fs_remove(&fc, vnode, dentry->d_name.name, false,
- dir_data_version);
+ afs_fs_remove(&fc, vnode, dentry->d_name.name, false, &scb[0]);
}
- afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
+ afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
+ &dir_data_version, &scb[0]);
ret = afs_end_vnode_operation(&fc);
if (ret == 0) {
drop_nlink(&vnode->vfs_inode);
@@ -182,6 +196,7 @@ static int afs_do_silly_unlink(struct afs_vnode *dvnode, struct afs_vnode *vnode
afs_edit_dir_for_unlink);
}
+ kfree(scb);
_leave(" = %d", ret);
return ret;
}