xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

NFS/pnfs: Bulk destroy of layouts needs to be safe w.r.t. umount

Browse Source 
If a bulk layout recall or a metadata server reboot coincides with a
umount, then holding a reference to an inode is unsafe unless we
also hold a reference to the super block.

Fixes: fd9a8d7160 ("NFSv4.1: Fix bulk recall and destroy of layouts")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust
2019-02-22 14:20:27 -05:00
parent 6f9449be53
commit 5085607d20
2 changed files with 24 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
fs/nfs/pnfs.c
View File

@@ -758,22 +758,35 @@ static int
pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
struct nfs_server *server,
struct list_head *layout_list)
__must_hold(&clp->cl_lock)
__must_hold(RCU)
{
struct pnfs_layout_hdr *lo, *next;
struct inode *inode;
list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
!list_empty(&lo->plh_bulk_destroy))
continue;
/* If the sb is being destroyed, just bail */
if (!nfs_sb_active(server->super))
break;
inode = igrab(lo->plh_inode);
if (inode == NULL)
continue;
list_del_init(&lo->plh_layouts);
if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
continue;
rcu_read_unlock();
spin_unlock(&clp->cl_lock);
iput(inode);
if (inode != NULL) {
list_del_init(&lo->plh_layouts);
if (pnfs_layout_add_bulk_destroy_list(inode,
layout_list))
continue;
rcu_read_unlock();
spin_unlock(&clp->cl_lock);
iput(inode);
} else {
rcu_read_unlock();
spin_unlock(&clp->cl_lock);
set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
}
nfs_sb_deactive(server->super);
spin_lock(&clp->cl_lock);
rcu_read_lock();
return -EAGAIN;
@@ -811,7 +824,7 @@ pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
/* Free all lsegs that are attached to commit buckets */
nfs_commit_inode(inode, 0);
pnfs_put_layout_hdr(lo);
iput(inode);
nfs_iput_and_deactive(inode);
}
return ret;
}