diff options
Diffstat (limited to 'fs/nfs/unlink.c')
| -rw-r--r-- | fs/nfs/unlink.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c new file mode 100644 index 000000000000..f732541a3332 --- /dev/null +++ b/fs/nfs/unlink.c @@ -0,0 +1,227 @@ +/* + * 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); + if (data->name.name != NULL) + 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) +{ + struct nfs_unlinkdata *data = (struct nfs_unlinkdata *)task->tk_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) +{ + struct nfs_unlinkdata *data = (struct nfs_unlinkdata *)task->tk_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(struct rpc_task *task) +{ + struct nfs_unlinkdata *data = (struct nfs_unlinkdata *)task->tk_calldata; + nfs_put_unlinkdata(data); +} + +/** + * 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_task *task; + struct rpc_clnt *clnt = NFS_CLIENT(dir->d_inode); + int status = -ENOMEM; + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + goto out; + memset(data, 0, sizeof(*data)); + + 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; + + task = &data->task; + rpc_init_task(task, clnt, nfs_async_unlink_done , RPC_TASK_ASYNC); + task->tk_calldata = data; + task->tk_action = nfs_async_unlink_init; + task->tk_release = nfs_async_unlink_release; + + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_NFSFS_RENAMED; + spin_unlock(&dentry->d_lock); + + rpc_sleep_on(&nfs_delete_queue, 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); +} |