linux-hardened/fs/nfs/proc.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 15:07:57 +01:00
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/nfs/proc.c
*
* Copyright (C) 1992, 1993, 1994 Rick Sladkey
*
* OS-independent nfs remote procedure call functions
*
* Tuned by Alan Cox <A.Cox@swansea.ac.uk> for >3K buffers
* so at last we can have decent(ish) throughput off a
* Sun server.
*
* Coding optimized and cleaned up by Florian La Roche.
* Note: Error returns are optimized for NFS_OK, which isn't translated via
* nfs_stat_to_errno(), but happens to be already the right return code.
*
* Also, the code currently doesn't check the size of the packet, when
* it decodes the packet.
*
* Feel free to fix it and mail me the diffs if it worries you.
*
* Completely rewritten to support the new RPC call interface;
* rewrote and moved the entire XDR stuff to xdr.c
* --Olaf Kirch June 1996
*
* The code below initializes all auto variables explicitly, otherwise
* it will fail to work as a module (gcc generates a memset call for an
* incomplete struct).
*/
#include <linux/types.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/lockd/bind.h>
#include <linux/freezer.h>
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_PROC
/*
* Bare-bones access to getattr: this is for nfs_read_super.
*/
static int
nfs_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fsinfo *info)
{
struct nfs_fattr *fattr = info->fattr;
struct nfs2_fsstat fsinfo;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_GETATTR],
.rpc_argp = fhandle,
.rpc_resp = fattr,
};
int status;
dprintk("%s: call getattr\n", __func__);
nfs_fattr_init(fattr);
status = rpc_call_sync(server->client, &msg, 0);
/* Retry with default authentication if different */
if (status && server->nfs_client->cl_rpcclient != server->client)
status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
dprintk("%s: reply getattr: %d\n", __func__, status);
if (status)
return status;
dprintk("%s: call statfs\n", __func__);
msg.rpc_proc = &nfs_procedures[NFSPROC_STATFS];
msg.rpc_resp = &fsinfo;
status = rpc_call_sync(server->client, &msg, 0);
/* Retry with default authentication if different */
if (status && server->nfs_client->cl_rpcclient != server->client)
status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
dprintk("%s: reply statfs: %d\n", __func__, status);
if (status)
return status;
info->rtmax = NFS_MAXDATA;
info->rtpref = fsinfo.tsize;
info->rtmult = fsinfo.bsize;
info->wtmax = NFS_MAXDATA;
info->wtpref = fsinfo.tsize;
info->wtmult = fsinfo.bsize;
info->dtpref = fsinfo.tsize;
info->maxfilesize = 0x7FFFFFFF;
info->lease_time = 0;
return 0;
}
/*
* One function for each procedure in the NFS protocol.
*/
static int
nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fattr *fattr, struct nfs4_label *label)
{
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_GETATTR],
.rpc_argp = fhandle,
.rpc_resp = fattr,
};
int status;
dprintk("NFS call getattr\n");
nfs_fattr_init(fattr);
status = rpc_call_sync(server->client, &msg, 0);
dprintk("NFS reply getattr: %d\n", status);
return status;
}
static int
nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
struct iattr *sattr)
{
struct inode *inode = d_inode(dentry);
struct nfs_sattrargs arg = {
.fh = NFS_FH(inode),
.sattr = sattr
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_SETATTR],
.rpc_argp = &arg,
.rpc_resp = fattr,
};
int status;
/* Mask out the non-modebit related stuff from attr->ia_mode */
sattr->ia_mode &= S_IALLUGO;
dprintk("NFS call setattr\n");
if (sattr->ia_valid & ATTR_FILE)
msg.rpc_cred = nfs_file_cred(sattr->ia_file);
nfs_fattr_init(fattr);
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
if (status == 0)
nfs_setattr_update_inode(inode, sattr, fattr);
dprintk("NFS reply setattr: %d\n", status);
return status;
}
static int
nfs_proc_lookup(struct inode *dir, const struct qstr *name,
struct nfs_fh *fhandle, struct nfs_fattr *fattr,
struct nfs4_label *label)
{
struct nfs_diropargs arg = {
.fh = NFS_FH(dir),
.name = name->name,
.len = name->len
};
struct nfs_diropok res = {
.fh = fhandle,
.fattr = fattr
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_LOOKUP],
.rpc_argp = &arg,
.rpc_resp = &res,
};
int status;
dprintk("NFS call lookup %s\n", name->name);
nfs_fattr_init(fattr);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
dprintk("NFS reply lookup: %d\n", status);
return status;
}
static int nfs_proc_readlink(struct inode *inode, struct page *page,
unsigned int pgbase, unsigned int pglen)
{
struct nfs_readlinkargs args = {
.fh = NFS_FH(inode),
.pgbase = pgbase,
.pglen = pglen,
.pages = &page
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_READLINK],
.rpc_argp = &args,
};
int status;
dprintk("NFS call readlink\n");
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
dprintk("NFS reply readlink: %d\n", status);
return status;
}
struct nfs_createdata {
struct nfs_createargs arg;
struct nfs_diropok res;
struct nfs_fh fhandle;
struct nfs_fattr fattr;
};
static struct nfs_createdata *nfs_alloc_createdata(struct inode *dir,
struct dentry *dentry, struct iattr *sattr)
{
struct nfs_createdata *data;
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (data != NULL) {
data->arg.fh = NFS_FH(dir);
data->arg.name = dentry->d_name.name;
data->arg.len = dentry->d_name.len;
data->arg.sattr = sattr;
nfs_fattr_init(&data->fattr);
data->fhandle.size = 0;
data->res.fh = &data->fhandle;
data->res.fattr = &data->fattr;
}
return data;
};
static void nfs_free_createdata(const struct nfs_createdata *data)
{
kfree(data);
}
static int
nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
int flags)
{
struct nfs_createdata *data;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_CREATE],
};
int status = -ENOMEM;
dprintk("NFS call create %pd\n", dentry);
data = nfs_alloc_createdata(dir, dentry, sattr);
if (data == NULL)
goto out;
msg.rpc_argp = &data->arg;
msg.rpc_resp = &data->res;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
if (status == 0)
status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
nfs_free_createdata(data);
out:
dprintk("NFS reply create: %d\n", status);
return status;
}
/*
* In NFSv2, mknod is grafted onto the create call.
*/
static int
nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
dev_t rdev)
{
struct nfs_createdata *data;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_CREATE],
};
umode_t mode;
int status = -ENOMEM;
dprintk("NFS call mknod %pd\n", dentry);
mode = sattr->ia_mode;
if (S_ISFIFO(mode)) {
sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
sattr->ia_valid &= ~ATTR_SIZE;
} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
sattr->ia_valid |= ATTR_SIZE;
sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
}
data = nfs_alloc_createdata(dir, dentry, sattr);
if (data == NULL)
goto out;
msg.rpc_argp = &data->arg;
msg.rpc_resp = &data->res;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
if (status == -EINVAL && S_ISFIFO(mode)) {
sattr->ia_mode = mode;
nfs_fattr_init(data->res.fattr);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
}
if (status == 0)
status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
nfs_free_createdata(data);
out:
dprintk("NFS reply mknod: %d\n", status);
return status;
}
static int
nfs_proc_remove(struct inode *dir, struct dentry *dentry)
{
struct nfs_removeargs arg = {
.fh = NFS_FH(dir),
.name = dentry->d_name,
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call remove %pd2\n",dentry);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
dprintk("NFS reply remove: %d\n", status);
return status;
}
static void
nfs_proc_unlink_setup(struct rpc_message *msg,
struct dentry *dentry,
struct inode *inode)
{
msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
}
static void nfs_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlinkdata *data)
{
rpc_call_start(task);
}
static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
{
nfs_mark_for_revalidate(dir);
return 1;
}
static void
nfs_proc_rename_setup(struct rpc_message *msg,
struct dentry *old_dentry,
struct dentry *new_dentry)
{
msg->rpc_proc = &nfs_procedures[NFSPROC_RENAME];
}
static void nfs_proc_rename_rpc_prepare(struct rpc_task *task, struct nfs_renamedata *data)
{
rpc_call_start(task);
}
static int
nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
struct inode *new_dir)
{
nfs_mark_for_revalidate(old_dir);
nfs_mark_for_revalidate(new_dir);
return 1;
}
static int
nfs_proc_link(struct inode *inode, struct inode *dir, const struct qstr *name)
{
struct nfs_linkargs arg = {
.fromfh = NFS_FH(inode),
.tofh = NFS_FH(dir),
.toname = name->name,
.tolen = name->len
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_LINK],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call link %s\n", name->name);
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
nfs_mark_for_revalidate(inode);
nfs_mark_for_revalidate(dir);
dprintk("NFS reply link: %d\n", status);
return status;
}
static int
nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
unsigned int len, struct iattr *sattr)
{
struct nfs_fh *fh;
struct nfs_fattr *fattr;
struct nfs_symlinkargs arg = {
.fromfh = NFS_FH(dir),
.fromname = dentry->d_name.name,
.fromlen = dentry->d_name.len,
.pages = &page,
.pathlen = len,
.sattr = sattr
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_SYMLINK],
.rpc_argp = &arg,
};
int status = -ENAMETOOLONG;
dprintk("NFS call symlink %pd\n", dentry);
if (len > NFS2_MAXPATHLEN)
goto out;
fh = nfs_alloc_fhandle();
fattr = nfs_alloc_fattr();
status = -ENOMEM;
if (fh == NULL || fattr == NULL)
goto out_free;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
/*
* V2 SYMLINK requests don't return any attributes. Setting the
* filehandle size to zero indicates to nfs_instantiate that it
* should fill in the data with a LOOKUP call on the wire.
*/
if (status == 0)
status = nfs_instantiate(dentry, fh, fattr, NULL);
out_free:
nfs_free_fattr(fattr);
nfs_free_fhandle(fh);
out:
dprintk("NFS reply symlink: %d\n", status);
return status;
}
static int
nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
{
struct nfs_createdata *data;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_MKDIR],
};
int status = -ENOMEM;
dprintk("NFS call mkdir %pd\n", dentry);
data = nfs_alloc_createdata(dir, dentry, sattr);
if (data == NULL)
goto out;
msg.rpc_argp = &data->arg;
msg.rpc_resp = &data->res;
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
if (status == 0)
status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
nfs_free_createdata(data);
out:
dprintk("NFS reply mkdir: %d\n", status);
return status;
}
static int
nfs_proc_rmdir(struct inode *dir, const struct qstr *name)
{
struct nfs_diropargs arg = {
.fh = NFS_FH(dir),
.name = name->name,
.len = name->len
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_RMDIR],
.rpc_argp = &arg,
};
int status;
dprintk("NFS call rmdir %s\n", name->name);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
dprintk("NFS reply rmdir: %d\n", status);
return status;
}
/*
* The READDIR implementation is somewhat hackish - we pass a temporary
* buffer to the encode function, which installs it in the receive
* the receive iovec. The decode function just parses the reply to make
* sure it is syntactically correct; the entries itself are decoded
* from nfs_readdir by calling the decode_entry function directly.
*/
static int
nfs_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
u64 cookie, struct page **pages, unsigned int count, bool plus)
{
struct inode *dir = d_inode(dentry);
struct nfs_readdirargs arg = {
.fh = NFS_FH(dir),
.cookie = cookie,
.count = count,
.pages = pages,
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_READDIR],
.rpc_argp = &arg,
.rpc_cred = cred,
};
int status;
dprintk("NFS call readdir %d\n", (unsigned int)cookie);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_invalidate_atime(dir);
dprintk("NFS reply readdir: %d\n", status);
return status;
}
static int
nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fsstat *stat)
{
struct nfs2_fsstat fsinfo;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_STATFS],
.rpc_argp = fhandle,
.rpc_resp = &fsinfo,
};
int status;
dprintk("NFS call statfs\n");
nfs_fattr_init(stat->fattr);
status = rpc_call_sync(server->client, &msg, 0);
dprintk("NFS reply statfs: %d\n", status);
if (status)
goto out;
stat->tbytes = (u64)fsinfo.blocks * fsinfo.bsize;
stat->fbytes = (u64)fsinfo.bfree * fsinfo.bsize;
stat->abytes = (u64)fsinfo.bavail * fsinfo.bsize;
stat->tfiles = 0;
stat->ffiles = 0;
stat->afiles = 0;
out:
return status;
}
static int
nfs_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fsinfo *info)
{
struct nfs2_fsstat fsinfo;
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_STATFS],
.rpc_argp = fhandle,
.rpc_resp = &fsinfo,
};
int status;
dprintk("NFS call fsinfo\n");
nfs_fattr_init(info->fattr);
status = rpc_call_sync(server->client, &msg, 0);
dprintk("NFS reply fsinfo: %d\n", status);
if (status)
goto out;
info->rtmax = NFS_MAXDATA;
info->rtpref = fsinfo.tsize;
info->rtmult = fsinfo.bsize;
info->wtmax = NFS_MAXDATA;
info->wtpref = fsinfo.tsize;
info->wtmult = fsinfo.bsize;
info->dtpref = fsinfo.tsize;
info->maxfilesize = 0x7FFFFFFF;
info->lease_time = 0;
out:
return status;
}
static int
nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_pathconf *info)
{
info->max_link = 0;
info->max_namelen = NFS2_MAXNAMLEN;
return 0;
}
static int nfs_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
{
struct inode *inode = hdr->inode;
nfs_invalidate_atime(inode);
if (task->tk_status >= 0) {
nfs_refresh_inode(inode, hdr->res.fattr);
/* Emulate the eof flag, which isn't normally needed in NFSv2
* as it is guaranteed to always return the file attributes
*/
if (hdr->args.offset + hdr->res.count >= hdr->res.fattr->size)
hdr->res.eof = 1;
}
return 0;
}
static void nfs_proc_read_setup(struct nfs_pgio_header *hdr,
struct rpc_message *msg)
{
msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
}
static int nfs_proc_pgio_rpc_prepare(struct rpc_task *task,
struct nfs_pgio_header *hdr)
{
rpc_call_start(task);
NFSv4: Don't try to recover NFSv4 locks when they are lost. When an NFSv4 client loses contact with the server it can lose any locks that it holds. Currently when it reconnects to the server it simply tries to reclaim those locks. This might succeed even though some other client has held and released a lock in the mean time. So the first client might think the file is unchanged, but it isn't. This isn't good. If, when recovery happens, the locks cannot be claimed because some other client still holds the lock, then we get a message in the kernel logs, but the client can still write. So two clients can both think they have a lock and can both write at the same time. This is equally not good. There was a patch a while ago http://comments.gmane.org/gmane.linux.nfs/41917 which tried to address some of this, but it didn't seem to go anywhere. That patch would also send a signal to the process. That might be useful but for now this patch just causes writes to fail. For NFSv4 (unlike v2/v3) there is a strong link between the lock and the write request so we can fairly easily fail any IO of the lock is gone. While some applications might not expect this, it is still safer than allowing the write to succeed. Because this is a fairly big change in behaviour a module parameter, "recover_locks", is introduced which defaults to true (the current behaviour) but can be set to "false" to tell the client not to try to recover things that were lost. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-04 09:04:49 +02:00
return 0;
}
static int nfs_write_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
{
if (task->tk_status >= 0)
nfs_writeback_update_inode(hdr);
return 0;
}
static void nfs_proc_write_setup(struct nfs_pgio_header *hdr,
struct rpc_message *msg,
struct rpc_clnt **clnt)
{
/* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
hdr->args.stable = NFS_FILE_SYNC;
msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
}
static void nfs_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
{
BUG();
}
static void
nfs_proc_commit_setup(struct nfs_commit_data *data, struct rpc_message *msg,
struct rpc_clnt **clnt)
{
BUG();
}
static int
nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
{
struct inode *inode = file_inode(filp);
return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl, NULL);
}
/* Helper functions for NFS lock bounds checking */
#define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
static int nfs_lock_check_bounds(const struct file_lock *fl)
{
__s32 start, end;
start = (__s32)fl->fl_start;
if ((loff_t)start != fl->fl_start)
goto out_einval;
if (fl->fl_end != OFFSET_MAX) {
end = (__s32)fl->fl_end;
if ((loff_t)end != fl->fl_end)
goto out_einval;
} else
end = NFS_LOCK32_OFFSET_MAX;
if (start < 0 || start > end)
goto out_einval;
return 0;
out_einval:
return -EINVAL;
}
static int nfs_have_delegation(struct inode *inode, fmode_t flags)
{
return 0;
}
static const struct inode_operations nfs_dir_inode_operations = {
.create = nfs_create,
.lookup = nfs_lookup,
.link = nfs_link,
.unlink = nfs_unlink,
.symlink = nfs_symlink,
.mkdir = nfs_mkdir,
.rmdir = nfs_rmdir,
.mknod = nfs_mknod,
.rename = nfs_rename,
.permission = nfs_permission,
.getattr = nfs_getattr,
.setattr = nfs_setattr,
};
static const struct inode_operations nfs_file_inode_operations = {
.permission = nfs_permission,
.getattr = nfs_getattr,
.setattr = nfs_setattr,
};
const struct nfs_rpc_ops nfs_v2_clientops = {
.version = 2, /* protocol version */
.dentry_ops = &nfs_dentry_operations,
.dir_inode_ops = &nfs_dir_inode_operations,
.file_inode_ops = &nfs_file_inode_operations,
.file_ops = &nfs_file_operations,
.getroot = nfs_proc_get_root,
.submount = nfs_submount,
.try_mount = nfs_try_mount,
.getattr = nfs_proc_getattr,
.setattr = nfs_proc_setattr,
.lookup = nfs_proc_lookup,
.access = NULL, /* access */
.readlink = nfs_proc_readlink,
.create = nfs_proc_create,
.remove = nfs_proc_remove,
.unlink_setup = nfs_proc_unlink_setup,
.unlink_rpc_prepare = nfs_proc_unlink_rpc_prepare,
.unlink_done = nfs_proc_unlink_done,
.rename_setup = nfs_proc_rename_setup,
.rename_rpc_prepare = nfs_proc_rename_rpc_prepare,
.rename_done = nfs_proc_rename_done,
.link = nfs_proc_link,
.symlink = nfs_proc_symlink,
.mkdir = nfs_proc_mkdir,
.rmdir = nfs_proc_rmdir,
.readdir = nfs_proc_readdir,
.mknod = nfs_proc_mknod,
.statfs = nfs_proc_statfs,
.fsinfo = nfs_proc_fsinfo,
.pathconf = nfs_proc_pathconf,
.decode_dirent = nfs2_decode_dirent,
.pgio_rpc_prepare = nfs_proc_pgio_rpc_prepare,
.read_setup = nfs_proc_read_setup,
.read_done = nfs_read_done,
.write_setup = nfs_proc_write_setup,
.write_done = nfs_write_done,
.commit_setup = nfs_proc_commit_setup,
.commit_rpc_prepare = nfs_proc_commit_rpc_prepare,
.lock = nfs_proc_lock,
.lock_check_bounds = nfs_lock_check_bounds,
.close_context = nfs_close_context,
.have_delegation = nfs_have_delegation,
.alloc_client = nfs_alloc_client,
.init_client = nfs_init_client,
.free_client = nfs_free_client,
.create_server = nfs_create_server,
.clone_server = nfs_clone_server,
};