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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-07-26 18:06:17 +0200 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-08-07 21:13:17 +0200 |
| commit | 5e11934d13c9a3bcb0cadad6c7a7de5c32660422 (patch) | |
| tree | 639e5660e9081bc16afccf0c509ff41c413b483d /fs | |
| parent | SUNRPC: Fix a race in rpciod_down() (diff) | |
| download | linux-5e11934d13c9a3bcb0cadad6c7a7de5c32660422.tar.xz linux-5e11934d13c9a3bcb0cadad6c7a7de5c32660422.zip | |
NFS: Fix put_nfs_open_context
We need to grab the inode->i_lock atomically with the last reference put in
order to remove the open context that is being freed from the
nfsi->open_files list.
Fix by converting the kref to a standard atomic counter and then using
atomic_dec_and_lock()...
Thanks to Arnd Bergmann for pointing out the problem.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/inode.c | 24 |
1 files changed, 8 insertions, 16 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index bca6cdcb9f0d..71a49c3acabd 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -468,7 +468,7 @@ static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, str ctx->lockowner = current->files; ctx->error = 0; ctx->dir_cookie = 0; - kref_init(&ctx->kref); + atomic_set(&ctx->count, 1); } return ctx; } @@ -476,21 +476,18 @@ static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, str struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx) { if (ctx != NULL) - kref_get(&ctx->kref); + atomic_inc(&ctx->count); return ctx; } -static void nfs_free_open_context(struct kref *kref) +void put_nfs_open_context(struct nfs_open_context *ctx) { - struct nfs_open_context *ctx = container_of(kref, - struct nfs_open_context, kref); + struct inode *inode = ctx->path.dentry->d_inode; - if (!list_empty(&ctx->list)) { - struct inode *inode = ctx->path.dentry->d_inode; - spin_lock(&inode->i_lock); - list_del(&ctx->list); - spin_unlock(&inode->i_lock); - } + if (!atomic_dec_and_lock(&ctx->count, &inode->i_lock)) + return; + list_del(&ctx->list); + spin_unlock(&inode->i_lock); if (ctx->state != NULL) nfs4_close_state(&ctx->path, ctx->state, ctx->mode); if (ctx->cred != NULL) @@ -500,11 +497,6 @@ static void nfs_free_open_context(struct kref *kref) kfree(ctx); } -void put_nfs_open_context(struct nfs_open_context *ctx) -{ - kref_put(&ctx->kref, nfs_free_open_context); -} - /* * Ensure that mmap has a recent RPC credential for use when writing out * shared pages |