/* * linux/fs/nfs/unlink.c * * nfs sillydelete handling * * NOTE: we rely on holding the BKL for list manipulation protection. */ #include <linux/slab.h> #include <linux/string.h> #include <linux/dcache.h> #include <linux/sunrpc/sched.h> #include <linux/sunrpc/clnt.h> #include <linux/nfs_fs.h> struct nfs_unlinkdata { struct nfs_unlinkdata *next; struct dentry *dir, *dentry; struct qstr name; struct rpc_task task; struct rpc_cred *cred; unsigned int count; }; static struct nfs_unlinkdata *nfs_deletes; static RPC_WAITQ(nfs_delete_queue, "nfs_delete_queue"); /** * nfs_detach_unlinkdata - Remove asynchronous unlink from global list * @data: pointer to descriptor */ static inline void nfs_detach_unlinkdata(struct nfs_unlinkdata *data) { struct nfs_unlinkdata **q; for (q = &nfs_deletes; *q != NULL; q = &((*q)->next)) { if (*q == data) { *q = data->next; break; } } } /** * nfs_put_unlinkdata - release data from a sillydelete operation. * @data: pointer to unlink structure. */ static void nfs_put_unlinkdata(struct nfs_unlinkdata *data) { if (--data->count == 0) { nfs_detach_unlinkdata(data); kfree(data->name.name); kfree(data); } } #define NAME_ALLOC_LEN(len) ((len+16) & ~15) /** * nfs_copy_dname - copy dentry name to data structure * @dentry: pointer to dentry * @data: nfs_unlinkdata */ static inline void nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data) { char *str; int len = dentry->d_name.len; str = kmalloc(NAME_ALLOC_LEN(len), GFP_KERNEL); if (!str) return; memcpy(str, dentry->d_name.name, len); if (!data->name.len) { data->name.len = len; data->name.name = str; } else kfree(str); } /** * nfs_async_unlink_init - Initialize the RPC info * @task: rpc_task of the sillydelete * * We delay initializing RPC info until after the call to dentry_iput() * in order to minimize races against rename(). */ static void nfs_async_unlink_init(struct rpc_task *task, void *calldata) { struct nfs_unlinkdata *data = calldata; struct dentry *dir = data->dir; struct rpc_message msg = { .rpc_cred = data->cred, }; int status = -ENOENT; if (!data->name.len) goto out_err; status = NFS_PROTO(dir->d_inode)->unlink_setup(&msg, dir, &data->name); if (status < 0) goto out_err; nfs_begin_data_update(dir->d_inode); rpc_call_setup(task, &msg, 0); return; out_err: rpc_exit(task, status); } /** * nfs_async_unlink_done - Sillydelete post-processing * @task: rpc_task of the sillydelete * * Do the directory attribute update. */ static void nfs_async_unlink_done(struct rpc_task *task, void *calldata) { struct nfs_unlinkdata *data = calldata; struct dentry *dir = data->dir; struct inode *dir_i; if (!dir) return; dir_i = dir->d_inode; nfs_end_data_update(dir_i); if (NFS_PROTO(dir_i)->unlink_done(dir, task)) return; put_rpccred(data->cred); data->cred = NULL; dput(dir); } /** * nfs_async_unlink_release - Release the sillydelete data. * @task: rpc_task of the sillydelete * * We need to call nfs_put_unlinkdata as a 'tk_release' task since the * rpc_task would be freed too. */ static void nfs_async_unlink_release(void *calldata) { struct nfs_unlinkdata *data = calldata; nfs_put_unlinkdata(data); } static const struct rpc_call_ops nfs_unlink_ops = { .rpc_call_prepare = nfs_async_unlink_init, .rpc_call_done = nfs_async_unlink_done, .rpc_release = nfs_async_unlink_release, }; /** * nfs_async_unlink - asynchronous unlinking of a file * @dentry: dentry to unlink */ int nfs_async_unlink(struct dentry *dentry) { struct dentry *dir = dentry->d_parent; struct nfs_unlinkdata *data; struct rpc_clnt *clnt = NFS_CLIENT(dir->d_inode); int status = -ENOMEM; data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) goto out; data->cred = rpcauth_lookupcred(clnt->cl_auth, 0); if (IS_ERR(data->cred)) { status = PTR_ERR(data->cred); goto out_free; } data->dir = dget(dir); data->dentry = dentry; data->next = nfs_deletes; nfs_deletes = data; data->count = 1; rpc_init_task(&data->task, clnt, RPC_TASK_ASYNC, &nfs_unlink_ops, data); spin_lock(&dentry->d_lock); dentry->d_flags |= DCACHE_NFSFS_RENAMED; spin_unlock(&dentry->d_lock); rpc_sleep_on(&nfs_delete_queue, &data->task, NULL, NULL); status = 0; out: return status; out_free: kfree(data); return status; } /** * nfs_complete_unlink - Initialize completion of the sillydelete * @dentry: dentry to delete * * Since we're most likely to be called by dentry_iput(), we * only use the dentry to find the sillydelete. We then copy the name * into the qstr. */ void nfs_complete_unlink(struct dentry *dentry) { struct nfs_unlinkdata *data; for(data = nfs_deletes; data != NULL; data = data->next) { if (dentry == data->dentry) break; } if (!data) return; data->count++; nfs_copy_dname(dentry, data); spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_NFSFS_RENAMED; spin_unlock(&dentry->d_lock); rpc_wake_up_task(&data->task); nfs_put_unlinkdata(data); }