From 22a0f15bee336aadddd53fa58fa27ff5a890672b Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Sun, 2 Feb 2014 12:16:07 -0800 Subject: [PATCH] Add support for O_TRUNC with nfs_open() O_TRUNC will attempt to truncate the file when opened with O_RDWR or O_WRONLY. Normal posix open(O_RDONLY|O_TRUNC) is undefined. libnfs nfs_open() only uses the O_TRUNC flag when used in combination with either O_RDWR or O_WRONLY. When O_TRUNC is used together with O_RDONLY libnfs will silently ignore the O_TRUNC flag. Libnfs nfs_open(O_RDONLY|O_TRUNC) is thus the same as nfs_open(O_RDONLY) --- include/nfsc/libnfs.h | 1 + lib/libnfs.c | 60 ++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 58 insertions(+), 3 deletions(-) diff --git a/include/nfsc/libnfs.h b/include/nfsc/libnfs.h index b9138c9..0504a6a 100644 --- a/include/nfsc/libnfs.h +++ b/include/nfsc/libnfs.h @@ -276,6 +276,7 @@ EXTERN int nfs_fstat(struct nfs_context *nfs, struct nfsfh *nfsfh, struct stat * * O_RDONLY * O_WRONLY * O_RDWR + * O_TRUNC (Only valid with O_RDWR or O_WRONLY. Ignored otherwise.) * * When the callback is invoked, status indicates the result: * 0 : Success. diff --git a/lib/libnfs.c b/lib/libnfs.c index bfb1b7c..c2c20d4 100644 --- a/lib/libnfs.c +++ b/lib/libnfs.c @@ -143,7 +143,6 @@ struct nfs_mcb_data { static int nfs_lookup_path_async_internal(struct nfs_context *nfs, struct nfs_cb_data *data, struct nfs_fh3 *fh); - void nfs_set_auth(struct nfs_context *nfs, struct AUTH *auth) { rpc_set_auth(nfs->rpc, auth); @@ -1244,6 +1243,37 @@ int nfs_stat_async(struct nfs_context *nfs, const char *path, nfs_cb cb, void *p /* * Async open() */ +static void nfs_open_trunc_cb(struct rpc_context *rpc, int status, void *command_data, void *private_data) +{ + struct nfs_cb_data *data = private_data; + struct nfs_context *nfs = data->nfs; + SETATTR3res *res; + + assert(rpc->magic == RPC_CONTEXT_MAGIC); + + if (status == RPC_STATUS_ERROR) { + data->cb(-EFAULT, nfs, command_data, data->private_data); + free_nfs_cb_data(data); + return; + } + if (status == RPC_STATUS_CANCEL) { + data->cb(-EINTR, nfs, "Command was cancelled", data->private_data); + free_nfs_cb_data(data); + return; + } + + res = command_data; + if (res->status != NFS3_OK) { + rpc_set_error(nfs->rpc, "NFS: Setattr failed with %s(%d)", nfsstat3_to_str(res->status), nfsstat3_to_errno(res->status)); + data->cb(nfsstat3_to_errno(res->status), nfs, rpc_get_error(nfs->rpc), data->private_data); + free_nfs_cb_data(data); + return; + } + + data->cb(0, nfs, NULL, data->private_data); + free_nfs_cb_data(data); +} + static void nfs_open_cb(struct rpc_context *rpc, int status, void *command_data, void *private_data) { ACCESS3res *res; @@ -1314,6 +1344,28 @@ static void nfs_open_cb(struct rpc_context *rpc, int status, void *command_data, nfsfh->fh = data->fh; data->fh.data.data_val = NULL; + /* Try to truncate it if we were requested to */ + if ((data->continue_int & O_TRUNC) && + (data->continue_int & (O_RDWR|O_WRONLY))) { + SETATTR3args args; + + memset(&args, 0, sizeof(SETATTR3args)); + args.object = nfsfh->fh; + args.new_attributes.size.set_it = 1; + args.new_attributes.size.set_size3_u.size = 0; + + if (rpc_nfs3_setattr_async(nfs->rpc, nfs_open_trunc_cb, &args, + data) != 0) { + rpc_set_error(nfs->rpc, "RPC error: Failed to send " + "SETATTR call for %s", data->path); + data->cb(-ENOMEM, nfs, rpc_get_error(nfs->rpc), + data->private_data); + free_nfs_cb_data(data); + return; + } + return; + } + data->cb(0, nfs, nfsfh, data->private_data); free_nfs_cb_data(data); } @@ -1338,8 +1390,10 @@ static int nfs_open_continue_internal(struct nfs_context *nfs, struct nfs_cb_dat args.access = nfsmode; if (rpc_nfs3_access_async(nfs->rpc, nfs_open_cb, &args, data) != 0) { - rpc_set_error(nfs->rpc, "RPC error: Failed to send OPEN ACCESS call for %s", data->path); - data->cb(-ENOMEM, nfs, rpc_get_error(nfs->rpc), data->private_data); + rpc_set_error(nfs->rpc, "RPC error: Failed to send OPEN ACCESS " + "call for %s", data->path); + data->cb(-ENOMEM, nfs, rpc_get_error(nfs->rpc), + data->private_data); free_nfs_cb_data(data); return -1; } -- 2.34.1