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- // SPDX-License-Identifier: GPL-2.0
- /*
- * File operations used by nfsd. Some of these have been ripped from
- * other parts of the kernel because they weren't exported, others
- * are partial duplicates with added or changed functionality.
- *
- * Note that several functions dget() the dentry upon which they want
- * to act, most notably those that create directory entries. Response
- * dentry's are dput()'d if necessary in the release callback.
- * So if you notice code paths that apparently fail to dput() the
- * dentry, don't worry--they have been taken care of.
- *
- * Copyright (C) 1995-1999 Olaf Kirch <[email protected]>
- * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <[email protected]>
- */
- #include <linux/fs.h>
- #include <linux/file.h>
- #include <linux/splice.h>
- #include <linux/falloc.h>
- #include <linux/fcntl.h>
- #include <linux/namei.h>
- #include <linux/delay.h>
- #include <linux/fsnotify.h>
- #include <linux/posix_acl_xattr.h>
- #include <linux/xattr.h>
- #include <linux/jhash.h>
- #include <linux/ima.h>
- #include <linux/pagemap.h>
- #include <linux/slab.h>
- #include <linux/uaccess.h>
- #include <linux/exportfs.h>
- #include <linux/writeback.h>
- #include <linux/security.h>
- #include "xdr3.h"
- #ifdef CONFIG_NFSD_V4
- #include "../internal.h"
- #include "acl.h"
- #include "idmap.h"
- #include "xdr4.h"
- #endif /* CONFIG_NFSD_V4 */
- #include "nfsd.h"
- #include "vfs.h"
- #include "filecache.h"
- #include "trace.h"
- #define NFSDDBG_FACILITY NFSDDBG_FILEOP
- /*
- * Called from nfsd_lookup and encode_dirent. Check if we have crossed
- * a mount point.
- * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
- * or nfs_ok having possibly changed *dpp and *expp
- */
- int
- nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
- struct svc_export **expp)
- {
- struct svc_export *exp = *expp, *exp2 = NULL;
- struct dentry *dentry = *dpp;
- struct path path = {.mnt = mntget(exp->ex_path.mnt),
- .dentry = dget(dentry)};
- int err = 0;
- err = follow_down(&path);
- if (err < 0)
- goto out;
- if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
- nfsd_mountpoint(dentry, exp) == 2) {
- /* This is only a mountpoint in some other namespace */
- path_put(&path);
- goto out;
- }
- exp2 = rqst_exp_get_by_name(rqstp, &path);
- if (IS_ERR(exp2)) {
- err = PTR_ERR(exp2);
- /*
- * We normally allow NFS clients to continue
- * "underneath" a mountpoint that is not exported.
- * The exception is V4ROOT, where no traversal is ever
- * allowed without an explicit export of the new
- * directory.
- */
- if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
- err = 0;
- path_put(&path);
- goto out;
- }
- if (nfsd_v4client(rqstp) ||
- (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
- /* successfully crossed mount point */
- /*
- * This is subtle: path.dentry is *not* on path.mnt
- * at this point. The only reason we are safe is that
- * original mnt is pinned down by exp, so we should
- * put path *before* putting exp
- */
- *dpp = path.dentry;
- path.dentry = dentry;
- *expp = exp2;
- exp2 = exp;
- }
- path_put(&path);
- exp_put(exp2);
- out:
- return err;
- }
- static void follow_to_parent(struct path *path)
- {
- struct dentry *dp;
- while (path->dentry == path->mnt->mnt_root && follow_up(path))
- ;
- dp = dget_parent(path->dentry);
- dput(path->dentry);
- path->dentry = dp;
- }
- static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
- {
- struct svc_export *exp2;
- struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
- .dentry = dget(dparent)};
- follow_to_parent(&path);
- exp2 = rqst_exp_parent(rqstp, &path);
- if (PTR_ERR(exp2) == -ENOENT) {
- *dentryp = dget(dparent);
- } else if (IS_ERR(exp2)) {
- path_put(&path);
- return PTR_ERR(exp2);
- } else {
- *dentryp = dget(path.dentry);
- exp_put(*exp);
- *exp = exp2;
- }
- path_put(&path);
- return 0;
- }
- /*
- * For nfsd purposes, we treat V4ROOT exports as though there was an
- * export at *every* directory.
- * We return:
- * '1' if this dentry *must* be an export point,
- * '2' if it might be, if there is really a mount here, and
- * '0' if there is no chance of an export point here.
- */
- int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
- {
- if (!d_inode(dentry))
- return 0;
- if (exp->ex_flags & NFSEXP_V4ROOT)
- return 1;
- if (nfsd4_is_junction(dentry))
- return 1;
- if (d_mountpoint(dentry))
- /*
- * Might only be a mountpoint in a different namespace,
- * but we need to check.
- */
- return 2;
- return 0;
- }
- __be32
- nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
- const char *name, unsigned int len,
- struct svc_export **exp_ret, struct dentry **dentry_ret)
- {
- struct svc_export *exp;
- struct dentry *dparent;
- struct dentry *dentry;
- int host_err;
- dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
- dparent = fhp->fh_dentry;
- exp = exp_get(fhp->fh_export);
- /* Lookup the name, but don't follow links */
- if (isdotent(name, len)) {
- if (len==1)
- dentry = dget(dparent);
- else if (dparent != exp->ex_path.dentry)
- dentry = dget_parent(dparent);
- else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
- dentry = dget(dparent); /* .. == . just like at / */
- else {
- /* checking mountpoint crossing is very different when stepping up */
- host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
- if (host_err)
- goto out_nfserr;
- }
- } else {
- dentry = lookup_one_len_unlocked(name, dparent, len);
- host_err = PTR_ERR(dentry);
- if (IS_ERR(dentry))
- goto out_nfserr;
- if (nfsd_mountpoint(dentry, exp)) {
- host_err = nfsd_cross_mnt(rqstp, &dentry, &exp);
- if (host_err) {
- dput(dentry);
- goto out_nfserr;
- }
- }
- }
- *dentry_ret = dentry;
- *exp_ret = exp;
- return 0;
- out_nfserr:
- exp_put(exp);
- return nfserrno(host_err);
- }
- /**
- * nfsd_lookup - look up a single path component for nfsd
- *
- * @rqstp: the request context
- * @fhp: the file handle of the directory
- * @name: the component name, or %NULL to look up parent
- * @len: length of name to examine
- * @resfh: pointer to pre-initialised filehandle to hold result.
- *
- * Look up one component of a pathname.
- * N.B. After this call _both_ fhp and resfh need an fh_put
- *
- * If the lookup would cross a mountpoint, and the mounted filesystem
- * is exported to the client with NFSEXP_NOHIDE, then the lookup is
- * accepted as it stands and the mounted directory is
- * returned. Otherwise the covered directory is returned.
- * NOTE: this mountpoint crossing is not supported properly by all
- * clients and is explicitly disallowed for NFSv3
- *
- */
- __be32
- nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
- unsigned int len, struct svc_fh *resfh)
- {
- struct svc_export *exp;
- struct dentry *dentry;
- __be32 err;
- err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
- if (err)
- return err;
- err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
- if (err)
- return err;
- err = check_nfsd_access(exp, rqstp);
- if (err)
- goto out;
- /*
- * Note: we compose the file handle now, but as the
- * dentry may be negative, it may need to be updated.
- */
- err = fh_compose(resfh, exp, dentry, fhp);
- if (!err && d_really_is_negative(dentry))
- err = nfserr_noent;
- out:
- dput(dentry);
- exp_put(exp);
- return err;
- }
- /*
- * Commit metadata changes to stable storage.
- */
- static int
- commit_inode_metadata(struct inode *inode)
- {
- const struct export_operations *export_ops = inode->i_sb->s_export_op;
- if (export_ops->commit_metadata)
- return export_ops->commit_metadata(inode);
- return sync_inode_metadata(inode, 1);
- }
- static int
- commit_metadata(struct svc_fh *fhp)
- {
- struct inode *inode = d_inode(fhp->fh_dentry);
- if (!EX_ISSYNC(fhp->fh_export))
- return 0;
- return commit_inode_metadata(inode);
- }
- /*
- * Go over the attributes and take care of the small differences between
- * NFS semantics and what Linux expects.
- */
- static void
- nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
- {
- /* Ignore mode updates on symlinks */
- if (S_ISLNK(inode->i_mode))
- iap->ia_valid &= ~ATTR_MODE;
- /* sanitize the mode change */
- if (iap->ia_valid & ATTR_MODE) {
- iap->ia_mode &= S_IALLUGO;
- iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
- }
- /* Revoke setuid/setgid on chown */
- if (!S_ISDIR(inode->i_mode) &&
- ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
- iap->ia_valid |= ATTR_KILL_PRIV;
- if (iap->ia_valid & ATTR_MODE) {
- /* we're setting mode too, just clear the s*id bits */
- iap->ia_mode &= ~S_ISUID;
- if (iap->ia_mode & S_IXGRP)
- iap->ia_mode &= ~S_ISGID;
- } else {
- /* set ATTR_KILL_* bits and let VFS handle it */
- iap->ia_valid |= ATTR_KILL_SUID;
- iap->ia_valid |=
- setattr_should_drop_sgid(&init_user_ns, inode);
- }
- }
- }
- static __be32
- nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct iattr *iap)
- {
- struct inode *inode = d_inode(fhp->fh_dentry);
- if (iap->ia_size < inode->i_size) {
- __be32 err;
- err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
- NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
- if (err)
- return err;
- }
- return nfserrno(get_write_access(inode));
- }
- static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap)
- {
- int host_err;
- if (iap->ia_valid & ATTR_SIZE) {
- /*
- * RFC5661, Section 18.30.4:
- * Changing the size of a file with SETATTR indirectly
- * changes the time_modify and change attributes.
- *
- * (and similar for the older RFCs)
- */
- struct iattr size_attr = {
- .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
- .ia_size = iap->ia_size,
- };
- if (iap->ia_size < 0)
- return -EFBIG;
- host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
- if (host_err)
- return host_err;
- iap->ia_valid &= ~ATTR_SIZE;
- /*
- * Avoid the additional setattr call below if the only other
- * attribute that the client sends is the mtime, as we update
- * it as part of the size change above.
- */
- if ((iap->ia_valid & ~ATTR_MTIME) == 0)
- return 0;
- }
- if (!iap->ia_valid)
- return 0;
- iap->ia_valid |= ATTR_CTIME;
- return notify_change(&init_user_ns, dentry, iap, NULL);
- }
- /**
- * nfsd_setattr - Set various file attributes.
- * @rqstp: controlling RPC transaction
- * @fhp: filehandle of target
- * @attr: attributes to set
- * @check_guard: set to 1 if guardtime is a valid timestamp
- * @guardtime: do not act if ctime.tv_sec does not match this timestamp
- *
- * This call may adjust the contents of @attr (in particular, this
- * call may change the bits in the na_iattr.ia_valid field).
- *
- * Returns nfs_ok on success, otherwise an NFS status code is
- * returned. Caller must release @fhp by calling fh_put in either
- * case.
- */
- __be32
- nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct nfsd_attrs *attr,
- int check_guard, time64_t guardtime)
- {
- struct dentry *dentry;
- struct inode *inode;
- struct iattr *iap = attr->na_iattr;
- int accmode = NFSD_MAY_SATTR;
- umode_t ftype = 0;
- __be32 err;
- int host_err;
- bool get_write_count;
- bool size_change = (iap->ia_valid & ATTR_SIZE);
- int retries;
- if (iap->ia_valid & ATTR_SIZE) {
- accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
- ftype = S_IFREG;
- }
- /*
- * If utimes(2) and friends are called with times not NULL, we should
- * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
- * will return EACCES, when the caller's effective UID does not match
- * the owner of the file, and the caller is not privileged. In this
- * situation, we should return EPERM(notify_change will return this).
- */
- if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
- accmode |= NFSD_MAY_OWNER_OVERRIDE;
- if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
- accmode |= NFSD_MAY_WRITE;
- }
- /* Callers that do fh_verify should do the fh_want_write: */
- get_write_count = !fhp->fh_dentry;
- /* Get inode */
- err = fh_verify(rqstp, fhp, ftype, accmode);
- if (err)
- return err;
- if (get_write_count) {
- host_err = fh_want_write(fhp);
- if (host_err)
- goto out;
- }
- dentry = fhp->fh_dentry;
- inode = d_inode(dentry);
- nfsd_sanitize_attrs(inode, iap);
- if (check_guard && guardtime != inode->i_ctime.tv_sec)
- return nfserr_notsync;
- /*
- * The size case is special, it changes the file in addition to the
- * attributes, and file systems don't expect it to be mixed with
- * "random" attribute changes. We thus split out the size change
- * into a separate call to ->setattr, and do the rest as a separate
- * setattr call.
- */
- if (size_change) {
- err = nfsd_get_write_access(rqstp, fhp, iap);
- if (err)
- return err;
- }
- inode_lock(inode);
- for (retries = 1;;) {
- struct iattr attrs;
- /*
- * notify_change() can alter its iattr argument, making
- * @iap unsuitable for submission multiple times. Make a
- * copy for every loop iteration.
- */
- attrs = *iap;
- host_err = __nfsd_setattr(dentry, &attrs);
- if (host_err != -EAGAIN || !retries--)
- break;
- if (!nfsd_wait_for_delegreturn(rqstp, inode))
- break;
- }
- if (attr->na_seclabel && attr->na_seclabel->len)
- attr->na_labelerr = security_inode_setsecctx(dentry,
- attr->na_seclabel->data, attr->na_seclabel->len);
- if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_pacl)
- attr->na_aclerr = set_posix_acl(&init_user_ns,
- inode, ACL_TYPE_ACCESS,
- attr->na_pacl);
- if (IS_ENABLED(CONFIG_FS_POSIX_ACL) &&
- !attr->na_aclerr && attr->na_dpacl && S_ISDIR(inode->i_mode))
- attr->na_aclerr = set_posix_acl(&init_user_ns,
- inode, ACL_TYPE_DEFAULT,
- attr->na_dpacl);
- inode_unlock(inode);
- if (size_change)
- put_write_access(inode);
- out:
- if (!host_err)
- host_err = commit_metadata(fhp);
- return nfserrno(host_err);
- }
- #if defined(CONFIG_NFSD_V4)
- /*
- * NFS junction information is stored in an extended attribute.
- */
- #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
- /**
- * nfsd4_is_junction - Test if an object could be an NFS junction
- *
- * @dentry: object to test
- *
- * Returns 1 if "dentry" appears to contain NFS junction information.
- * Otherwise 0 is returned.
- */
- int nfsd4_is_junction(struct dentry *dentry)
- {
- struct inode *inode = d_inode(dentry);
- if (inode == NULL)
- return 0;
- if (inode->i_mode & S_IXUGO)
- return 0;
- if (!(inode->i_mode & S_ISVTX))
- return 0;
- if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
- NULL, 0) <= 0)
- return 0;
- return 1;
- }
- static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp)
- {
- return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate;
- }
- __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
- struct nfsd_file *nf_src, u64 src_pos,
- struct nfsd_file *nf_dst, u64 dst_pos,
- u64 count, bool sync)
- {
- struct file *src = nf_src->nf_file;
- struct file *dst = nf_dst->nf_file;
- errseq_t since;
- loff_t cloned;
- __be32 ret = 0;
- since = READ_ONCE(dst->f_wb_err);
- cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
- if (cloned < 0) {
- ret = nfserrno(cloned);
- goto out_err;
- }
- if (count && cloned != count) {
- ret = nfserrno(-EINVAL);
- goto out_err;
- }
- if (sync) {
- loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
- int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
- if (!status)
- status = filemap_check_wb_err(dst->f_mapping, since);
- if (!status)
- status = commit_inode_metadata(file_inode(src));
- if (status < 0) {
- struct nfsd_net *nn = net_generic(nf_dst->nf_net,
- nfsd_net_id);
- trace_nfsd_clone_file_range_err(rqstp,
- &nfsd4_get_cstate(rqstp)->save_fh,
- src_pos,
- &nfsd4_get_cstate(rqstp)->current_fh,
- dst_pos,
- count, status);
- nfsd_reset_write_verifier(nn);
- trace_nfsd_writeverf_reset(nn, rqstp, status);
- ret = nfserrno(status);
- }
- }
- out_err:
- return ret;
- }
- ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
- u64 dst_pos, u64 count)
- {
- ssize_t ret;
- /*
- * Limit copy to 4MB to prevent indefinitely blocking an nfsd
- * thread and client rpc slot. The choice of 4MB is somewhat
- * arbitrary. We might instead base this on r/wsize, or make it
- * tunable, or use a time instead of a byte limit, or implement
- * asynchronous copy. In theory a client could also recognize a
- * limit like this and pipeline multiple COPY requests.
- */
- count = min_t(u64, count, 1 << 22);
- ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
- if (ret == -EOPNOTSUPP || ret == -EXDEV)
- ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
- COPY_FILE_SPLICE);
- return ret;
- }
- __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct file *file, loff_t offset, loff_t len,
- int flags)
- {
- int error;
- if (!S_ISREG(file_inode(file)->i_mode))
- return nfserr_inval;
- error = vfs_fallocate(file, flags, offset, len);
- if (!error)
- error = commit_metadata(fhp);
- return nfserrno(error);
- }
- #endif /* defined(CONFIG_NFSD_V4) */
- /*
- * Check server access rights to a file system object
- */
- struct accessmap {
- u32 access;
- int how;
- };
- static struct accessmap nfs3_regaccess[] = {
- { NFS3_ACCESS_READ, NFSD_MAY_READ },
- { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
- { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
- { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
- #ifdef CONFIG_NFSD_V4
- { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
- { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
- { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
- #endif
- { 0, 0 }
- };
- static struct accessmap nfs3_diraccess[] = {
- { NFS3_ACCESS_READ, NFSD_MAY_READ },
- { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
- { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
- { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
- { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
- #ifdef CONFIG_NFSD_V4
- { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
- { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
- { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
- #endif
- { 0, 0 }
- };
- static struct accessmap nfs3_anyaccess[] = {
- /* Some clients - Solaris 2.6 at least, make an access call
- * to the server to check for access for things like /dev/null
- * (which really, the server doesn't care about). So
- * We provide simple access checking for them, looking
- * mainly at mode bits, and we make sure to ignore read-only
- * filesystem checks
- */
- { NFS3_ACCESS_READ, NFSD_MAY_READ },
- { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
- { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
- { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
- { 0, 0 }
- };
- __be32
- nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
- {
- struct accessmap *map;
- struct svc_export *export;
- struct dentry *dentry;
- u32 query, result = 0, sresult = 0;
- __be32 error;
- error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
- if (error)
- goto out;
- export = fhp->fh_export;
- dentry = fhp->fh_dentry;
- if (d_is_reg(dentry))
- map = nfs3_regaccess;
- else if (d_is_dir(dentry))
- map = nfs3_diraccess;
- else
- map = nfs3_anyaccess;
- query = *access;
- for (; map->access; map++) {
- if (map->access & query) {
- __be32 err2;
- sresult |= map->access;
- err2 = nfsd_permission(rqstp, export, dentry, map->how);
- switch (err2) {
- case nfs_ok:
- result |= map->access;
- break;
-
- /* the following error codes just mean the access was not allowed,
- * rather than an error occurred */
- case nfserr_rofs:
- case nfserr_acces:
- case nfserr_perm:
- /* simply don't "or" in the access bit. */
- break;
- default:
- error = err2;
- goto out;
- }
- }
- }
- *access = result;
- if (supported)
- *supported = sresult;
- out:
- return error;
- }
- int nfsd_open_break_lease(struct inode *inode, int access)
- {
- unsigned int mode;
- if (access & NFSD_MAY_NOT_BREAK_LEASE)
- return 0;
- mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
- return break_lease(inode, mode | O_NONBLOCK);
- }
- /*
- * Open an existing file or directory.
- * The may_flags argument indicates the type of open (read/write/lock)
- * and additional flags.
- * N.B. After this call fhp needs an fh_put
- */
- static __be32
- __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
- int may_flags, struct file **filp)
- {
- struct path path;
- struct inode *inode;
- struct file *file;
- int flags = O_RDONLY|O_LARGEFILE;
- __be32 err;
- int host_err = 0;
- path.mnt = fhp->fh_export->ex_path.mnt;
- path.dentry = fhp->fh_dentry;
- inode = d_inode(path.dentry);
- err = nfserr_perm;
- if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
- goto out;
- if (!inode->i_fop)
- goto out;
- host_err = nfsd_open_break_lease(inode, may_flags);
- if (host_err) /* NOMEM or WOULDBLOCK */
- goto out_nfserr;
- if (may_flags & NFSD_MAY_WRITE) {
- if (may_flags & NFSD_MAY_READ)
- flags = O_RDWR|O_LARGEFILE;
- else
- flags = O_WRONLY|O_LARGEFILE;
- }
- file = dentry_open(&path, flags, current_cred());
- if (IS_ERR(file)) {
- host_err = PTR_ERR(file);
- goto out_nfserr;
- }
- host_err = ima_file_check(file, may_flags);
- if (host_err) {
- fput(file);
- goto out_nfserr;
- }
- if (may_flags & NFSD_MAY_64BIT_COOKIE)
- file->f_mode |= FMODE_64BITHASH;
- else
- file->f_mode |= FMODE_32BITHASH;
- *filp = file;
- out_nfserr:
- err = nfserrno(host_err);
- out:
- return err;
- }
- __be32
- nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
- int may_flags, struct file **filp)
- {
- __be32 err;
- bool retried = false;
- validate_process_creds();
- /*
- * If we get here, then the client has already done an "open",
- * and (hopefully) checked permission - so allow OWNER_OVERRIDE
- * in case a chmod has now revoked permission.
- *
- * Arguably we should also allow the owner override for
- * directories, but we never have and it doesn't seem to have
- * caused anyone a problem. If we were to change this, note
- * also that our filldir callbacks would need a variant of
- * lookup_one_len that doesn't check permissions.
- */
- if (type == S_IFREG)
- may_flags |= NFSD_MAY_OWNER_OVERRIDE;
- retry:
- err = fh_verify(rqstp, fhp, type, may_flags);
- if (!err) {
- err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
- if (err == nfserr_stale && !retried) {
- retried = true;
- fh_put(fhp);
- goto retry;
- }
- }
- validate_process_creds();
- return err;
- }
- /**
- * nfsd_open_verified - Open a regular file for the filecache
- * @rqstp: RPC request
- * @fhp: NFS filehandle of the file to open
- * @may_flags: internal permission flags
- * @filp: OUT: open "struct file *"
- *
- * Returns an nfsstat value in network byte order.
- */
- __be32
- nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
- struct file **filp)
- {
- __be32 err;
- validate_process_creds();
- err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
- validate_process_creds();
- return err;
- }
- /*
- * Grab and keep cached pages associated with a file in the svc_rqst
- * so that they can be passed to the network sendmsg/sendpage routines
- * directly. They will be released after the sending has completed.
- */
- static int
- nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
- struct splice_desc *sd)
- {
- struct svc_rqst *rqstp = sd->u.data;
- struct page *page = buf->page; // may be a compound one
- unsigned offset = buf->offset;
- struct page *last_page;
- last_page = page + (offset + sd->len - 1) / PAGE_SIZE;
- for (page += offset / PAGE_SIZE; page <= last_page; page++) {
- /*
- * Skip page replacement when extending the contents
- * of the current page.
- */
- if (page == *(rqstp->rq_next_page - 1))
- continue;
- svc_rqst_replace_page(rqstp, page);
- }
- if (rqstp->rq_res.page_len == 0) // first call
- rqstp->rq_res.page_base = offset % PAGE_SIZE;
- rqstp->rq_res.page_len += sd->len;
- return sd->len;
- }
- static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
- struct splice_desc *sd)
- {
- return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
- }
- static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
- size_t expected)
- {
- if (expected != 0 && len == 0)
- return 1;
- if (offset+len >= i_size_read(file_inode(file)))
- return 1;
- return 0;
- }
- static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct file *file, loff_t offset,
- unsigned long *count, u32 *eof, ssize_t host_err)
- {
- if (host_err >= 0) {
- nfsd_stats_io_read_add(fhp->fh_export, host_err);
- *eof = nfsd_eof_on_read(file, offset, host_err, *count);
- *count = host_err;
- fsnotify_access(file);
- trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
- return 0;
- } else {
- trace_nfsd_read_err(rqstp, fhp, offset, host_err);
- return nfserrno(host_err);
- }
- }
- __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct file *file, loff_t offset, unsigned long *count,
- u32 *eof)
- {
- struct splice_desc sd = {
- .len = 0,
- .total_len = *count,
- .pos = offset,
- .u.data = rqstp,
- };
- ssize_t host_err;
- trace_nfsd_read_splice(rqstp, fhp, offset, *count);
- rqstp->rq_next_page = rqstp->rq_respages + 1;
- host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
- return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
- }
- __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct file *file, loff_t offset,
- struct kvec *vec, int vlen, unsigned long *count,
- u32 *eof)
- {
- struct iov_iter iter;
- loff_t ppos = offset;
- ssize_t host_err;
- trace_nfsd_read_vector(rqstp, fhp, offset, *count);
- iov_iter_kvec(&iter, ITER_DEST, vec, vlen, *count);
- host_err = vfs_iter_read(file, &iter, &ppos, 0);
- return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
- }
- /*
- * Gathered writes: If another process is currently writing to the file,
- * there's a high chance this is another nfsd (triggered by a bulk write
- * from a client's biod). Rather than syncing the file with each write
- * request, we sleep for 10 msec.
- *
- * I don't know if this roughly approximates C. Juszak's idea of
- * gathered writes, but it's a nice and simple solution (IMHO), and it
- * seems to work:-)
- *
- * Note: we do this only in the NFSv2 case, since v3 and higher have a
- * better tool (separate unstable writes and commits) for solving this
- * problem.
- */
- static int wait_for_concurrent_writes(struct file *file)
- {
- struct inode *inode = file_inode(file);
- static ino_t last_ino;
- static dev_t last_dev;
- int err = 0;
- if (atomic_read(&inode->i_writecount) > 1
- || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
- dprintk("nfsd: write defer %d\n", task_pid_nr(current));
- msleep(10);
- dprintk("nfsd: write resume %d\n", task_pid_nr(current));
- }
- if (inode->i_state & I_DIRTY) {
- dprintk("nfsd: write sync %d\n", task_pid_nr(current));
- err = vfs_fsync(file, 0);
- }
- last_ino = inode->i_ino;
- last_dev = inode->i_sb->s_dev;
- return err;
- }
- __be32
- nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
- loff_t offset, struct kvec *vec, int vlen,
- unsigned long *cnt, int stable,
- __be32 *verf)
- {
- struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
- struct file *file = nf->nf_file;
- struct super_block *sb = file_inode(file)->i_sb;
- struct svc_export *exp;
- struct iov_iter iter;
- errseq_t since;
- __be32 nfserr;
- int host_err;
- int use_wgather;
- loff_t pos = offset;
- unsigned long exp_op_flags = 0;
- unsigned int pflags = current->flags;
- rwf_t flags = 0;
- bool restore_flags = false;
- trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
- if (sb->s_export_op)
- exp_op_flags = sb->s_export_op->flags;
- if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
- !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
- /*
- * We want throttling in balance_dirty_pages()
- * and shrink_inactive_list() to only consider
- * the backingdev we are writing to, so that nfs to
- * localhost doesn't cause nfsd to lock up due to all
- * the client's dirty pages or its congested queue.
- */
- current->flags |= PF_LOCAL_THROTTLE;
- restore_flags = true;
- }
- exp = fhp->fh_export;
- use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
- if (!EX_ISSYNC(exp))
- stable = NFS_UNSTABLE;
- if (stable && !use_wgather)
- flags |= RWF_SYNC;
- iov_iter_kvec(&iter, ITER_SOURCE, vec, vlen, *cnt);
- since = READ_ONCE(file->f_wb_err);
- if (verf)
- nfsd_copy_write_verifier(verf, nn);
- file_start_write(file);
- host_err = vfs_iter_write(file, &iter, &pos, flags);
- file_end_write(file);
- if (host_err < 0) {
- nfsd_reset_write_verifier(nn);
- trace_nfsd_writeverf_reset(nn, rqstp, host_err);
- goto out_nfserr;
- }
- *cnt = host_err;
- nfsd_stats_io_write_add(exp, *cnt);
- fsnotify_modify(file);
- host_err = filemap_check_wb_err(file->f_mapping, since);
- if (host_err < 0)
- goto out_nfserr;
- if (stable && use_wgather) {
- host_err = wait_for_concurrent_writes(file);
- if (host_err < 0) {
- nfsd_reset_write_verifier(nn);
- trace_nfsd_writeverf_reset(nn, rqstp, host_err);
- }
- }
- out_nfserr:
- if (host_err >= 0) {
- trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
- nfserr = nfs_ok;
- } else {
- trace_nfsd_write_err(rqstp, fhp, offset, host_err);
- nfserr = nfserrno(host_err);
- }
- if (restore_flags)
- current_restore_flags(pflags, PF_LOCAL_THROTTLE);
- return nfserr;
- }
- /*
- * Read data from a file. count must contain the requested read count
- * on entry. On return, *count contains the number of bytes actually read.
- * N.B. After this call fhp needs an fh_put
- */
- __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
- loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
- u32 *eof)
- {
- struct nfsd_file *nf;
- struct file *file;
- __be32 err;
- trace_nfsd_read_start(rqstp, fhp, offset, *count);
- err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_READ, &nf);
- if (err)
- return err;
- file = nf->nf_file;
- if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
- err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
- else
- err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
- nfsd_file_put(nf);
- trace_nfsd_read_done(rqstp, fhp, offset, *count);
- return err;
- }
- /*
- * Write data to a file.
- * The stable flag requests synchronous writes.
- * N.B. After this call fhp needs an fh_put
- */
- __be32
- nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
- struct kvec *vec, int vlen, unsigned long *cnt, int stable,
- __be32 *verf)
- {
- struct nfsd_file *nf;
- __be32 err;
- trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
- err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_WRITE, &nf);
- if (err)
- goto out;
- err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
- vlen, cnt, stable, verf);
- nfsd_file_put(nf);
- out:
- trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
- return err;
- }
- /**
- * nfsd_commit - Commit pending writes to stable storage
- * @rqstp: RPC request being processed
- * @fhp: NFS filehandle
- * @nf: target file
- * @offset: raw offset from beginning of file
- * @count: raw count of bytes to sync
- * @verf: filled in with the server's current write verifier
- *
- * Note: we guarantee that data that lies within the range specified
- * by the 'offset' and 'count' parameters will be synced. The server
- * is permitted to sync data that lies outside this range at the
- * same time.
- *
- * Unfortunately we cannot lock the file to make sure we return full WCC
- * data to the client, as locking happens lower down in the filesystem.
- *
- * Return values:
- * An nfsstat value in network byte order.
- */
- __be32
- nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
- u64 offset, u32 count, __be32 *verf)
- {
- __be32 err = nfs_ok;
- u64 maxbytes;
- loff_t start, end;
- struct nfsd_net *nn;
- /*
- * Convert the client-provided (offset, count) range to a
- * (start, end) range. If the client-provided range falls
- * outside the maximum file size of the underlying FS,
- * clamp the sync range appropriately.
- */
- start = 0;
- end = LLONG_MAX;
- maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
- if (offset < maxbytes) {
- start = offset;
- if (count && (offset + count - 1 < maxbytes))
- end = offset + count - 1;
- }
- nn = net_generic(nf->nf_net, nfsd_net_id);
- if (EX_ISSYNC(fhp->fh_export)) {
- errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
- int err2;
- err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
- switch (err2) {
- case 0:
- nfsd_copy_write_verifier(verf, nn);
- err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
- since);
- err = nfserrno(err2);
- break;
- case -EINVAL:
- err = nfserr_notsupp;
- break;
- default:
- nfsd_reset_write_verifier(nn);
- trace_nfsd_writeverf_reset(nn, rqstp, err2);
- err = nfserrno(err2);
- }
- } else
- nfsd_copy_write_verifier(verf, nn);
- return err;
- }
- /**
- * nfsd_create_setattr - Set a created file's attributes
- * @rqstp: RPC transaction being executed
- * @fhp: NFS filehandle of parent directory
- * @resfhp: NFS filehandle of new object
- * @attrs: requested attributes of new object
- *
- * Returns nfs_ok on success, or an nfsstat in network byte order.
- */
- __be32
- nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct svc_fh *resfhp, struct nfsd_attrs *attrs)
- {
- struct iattr *iap = attrs->na_iattr;
- __be32 status;
- /*
- * Mode has already been set by file creation.
- */
- iap->ia_valid &= ~ATTR_MODE;
- /*
- * Setting uid/gid works only for root. Irix appears to
- * send along the gid on create when it tries to implement
- * setgid directories via NFS:
- */
- if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
- iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
- /*
- * Callers expect new file metadata to be committed even
- * if the attributes have not changed.
- */
- if (iap->ia_valid)
- status = nfsd_setattr(rqstp, resfhp, attrs, 0, (time64_t)0);
- else
- status = nfserrno(commit_metadata(resfhp));
- /*
- * Transactional filesystems had a chance to commit changes
- * for both parent and child simultaneously making the
- * following commit_metadata a noop in many cases.
- */
- if (!status)
- status = nfserrno(commit_metadata(fhp));
- /*
- * Update the new filehandle to pick up the new attributes.
- */
- if (!status)
- status = fh_update(resfhp);
- return status;
- }
- /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
- * setting size to 0 may fail for some specific file systems by the permission
- * checking which requires WRITE permission but the mode is 000.
- * we ignore the resizing(to 0) on the just new created file, since the size is
- * 0 after file created.
- *
- * call this only after vfs_create() is called.
- * */
- static void
- nfsd_check_ignore_resizing(struct iattr *iap)
- {
- if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
- iap->ia_valid &= ~ATTR_SIZE;
- }
- /* The parent directory should already be locked: */
- __be32
- nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
- struct nfsd_attrs *attrs,
- int type, dev_t rdev, struct svc_fh *resfhp)
- {
- struct dentry *dentry, *dchild;
- struct inode *dirp;
- struct iattr *iap = attrs->na_iattr;
- __be32 err;
- int host_err;
- dentry = fhp->fh_dentry;
- dirp = d_inode(dentry);
- dchild = dget(resfhp->fh_dentry);
- err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
- if (err)
- goto out;
- if (!(iap->ia_valid & ATTR_MODE))
- iap->ia_mode = 0;
- iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
- if (!IS_POSIXACL(dirp))
- iap->ia_mode &= ~current_umask();
- err = 0;
- host_err = 0;
- switch (type) {
- case S_IFREG:
- host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
- if (!host_err)
- nfsd_check_ignore_resizing(iap);
- break;
- case S_IFDIR:
- host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
- if (!host_err && unlikely(d_unhashed(dchild))) {
- struct dentry *d;
- d = lookup_one_len(dchild->d_name.name,
- dchild->d_parent,
- dchild->d_name.len);
- if (IS_ERR(d)) {
- host_err = PTR_ERR(d);
- break;
- }
- if (unlikely(d_is_negative(d))) {
- dput(d);
- err = nfserr_serverfault;
- goto out;
- }
- dput(resfhp->fh_dentry);
- resfhp->fh_dentry = dget(d);
- err = fh_update(resfhp);
- dput(dchild);
- dchild = d;
- if (err)
- goto out;
- }
- break;
- case S_IFCHR:
- case S_IFBLK:
- case S_IFIFO:
- case S_IFSOCK:
- host_err = vfs_mknod(&init_user_ns, dirp, dchild,
- iap->ia_mode, rdev);
- break;
- default:
- printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
- type);
- host_err = -EINVAL;
- }
- if (host_err < 0)
- goto out_nfserr;
- err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
- out:
- dput(dchild);
- return err;
- out_nfserr:
- err = nfserrno(host_err);
- goto out;
- }
- /*
- * Create a filesystem object (regular, directory, special).
- * Note that the parent directory is left locked.
- *
- * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
- */
- __be32
- nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
- char *fname, int flen, struct nfsd_attrs *attrs,
- int type, dev_t rdev, struct svc_fh *resfhp)
- {
- struct dentry *dentry, *dchild = NULL;
- __be32 err;
- int host_err;
- if (isdotent(fname, flen))
- return nfserr_exist;
- err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
- if (err)
- return err;
- dentry = fhp->fh_dentry;
- host_err = fh_want_write(fhp);
- if (host_err)
- return nfserrno(host_err);
- inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
- dchild = lookup_one_len(fname, dentry, flen);
- host_err = PTR_ERR(dchild);
- if (IS_ERR(dchild)) {
- err = nfserrno(host_err);
- goto out_unlock;
- }
- err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
- /*
- * We unconditionally drop our ref to dchild as fh_compose will have
- * already grabbed its own ref for it.
- */
- dput(dchild);
- if (err)
- goto out_unlock;
- fh_fill_pre_attrs(fhp);
- err = nfsd_create_locked(rqstp, fhp, attrs, type, rdev, resfhp);
- fh_fill_post_attrs(fhp);
- out_unlock:
- inode_unlock(dentry->d_inode);
- return err;
- }
- /*
- * Read a symlink. On entry, *lenp must contain the maximum path length that
- * fits into the buffer. On return, it contains the true length.
- * N.B. After this call fhp needs an fh_put
- */
- __be32
- nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
- {
- __be32 err;
- const char *link;
- struct path path;
- DEFINE_DELAYED_CALL(done);
- int len;
- err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
- if (unlikely(err))
- return err;
- path.mnt = fhp->fh_export->ex_path.mnt;
- path.dentry = fhp->fh_dentry;
- if (unlikely(!d_is_symlink(path.dentry)))
- return nfserr_inval;
- touch_atime(&path);
- link = vfs_get_link(path.dentry, &done);
- if (IS_ERR(link))
- return nfserrno(PTR_ERR(link));
- len = strlen(link);
- if (len < *lenp)
- *lenp = len;
- memcpy(buf, link, *lenp);
- do_delayed_call(&done);
- return 0;
- }
- /**
- * nfsd_symlink - Create a symlink and look up its inode
- * @rqstp: RPC transaction being executed
- * @fhp: NFS filehandle of parent directory
- * @fname: filename of the new symlink
- * @flen: length of @fname
- * @path: content of the new symlink (NUL-terminated)
- * @attrs: requested attributes of new object
- * @resfhp: NFS filehandle of new object
- *
- * N.B. After this call _both_ fhp and resfhp need an fh_put
- *
- * Returns nfs_ok on success, or an nfsstat in network byte order.
- */
- __be32
- nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
- char *fname, int flen,
- char *path, struct nfsd_attrs *attrs,
- struct svc_fh *resfhp)
- {
- struct dentry *dentry, *dnew;
- __be32 err, cerr;
- int host_err;
- err = nfserr_noent;
- if (!flen || path[0] == '\0')
- goto out;
- err = nfserr_exist;
- if (isdotent(fname, flen))
- goto out;
- err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
- if (err)
- goto out;
- host_err = fh_want_write(fhp);
- if (host_err) {
- err = nfserrno(host_err);
- goto out;
- }
- dentry = fhp->fh_dentry;
- inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
- dnew = lookup_one_len(fname, dentry, flen);
- if (IS_ERR(dnew)) {
- err = nfserrno(PTR_ERR(dnew));
- inode_unlock(dentry->d_inode);
- goto out_drop_write;
- }
- fh_fill_pre_attrs(fhp);
- host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
- err = nfserrno(host_err);
- cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
- if (!err)
- nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
- fh_fill_post_attrs(fhp);
- inode_unlock(dentry->d_inode);
- if (!err)
- err = nfserrno(commit_metadata(fhp));
- dput(dnew);
- if (err==0) err = cerr;
- out_drop_write:
- fh_drop_write(fhp);
- out:
- return err;
- }
- /*
- * Create a hardlink
- * N.B. After this call _both_ ffhp and tfhp need an fh_put
- */
- __be32
- nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
- char *name, int len, struct svc_fh *tfhp)
- {
- struct dentry *ddir, *dnew, *dold;
- struct inode *dirp;
- __be32 err;
- int host_err;
- err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
- if (err)
- goto out;
- err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
- if (err)
- goto out;
- err = nfserr_isdir;
- if (d_is_dir(tfhp->fh_dentry))
- goto out;
- err = nfserr_perm;
- if (!len)
- goto out;
- err = nfserr_exist;
- if (isdotent(name, len))
- goto out;
- host_err = fh_want_write(tfhp);
- if (host_err) {
- err = nfserrno(host_err);
- goto out;
- }
- ddir = ffhp->fh_dentry;
- dirp = d_inode(ddir);
- inode_lock_nested(dirp, I_MUTEX_PARENT);
- dnew = lookup_one_len(name, ddir, len);
- if (IS_ERR(dnew)) {
- err = nfserrno(PTR_ERR(dnew));
- goto out_unlock;
- }
- dold = tfhp->fh_dentry;
- err = nfserr_noent;
- if (d_really_is_negative(dold))
- goto out_dput;
- fh_fill_pre_attrs(ffhp);
- host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
- fh_fill_post_attrs(ffhp);
- inode_unlock(dirp);
- if (!host_err) {
- err = nfserrno(commit_metadata(ffhp));
- if (!err)
- err = nfserrno(commit_metadata(tfhp));
- } else {
- if (host_err == -EXDEV && rqstp->rq_vers == 2)
- err = nfserr_acces;
- else
- err = nfserrno(host_err);
- }
- dput(dnew);
- out_drop_write:
- fh_drop_write(tfhp);
- out:
- return err;
- out_dput:
- dput(dnew);
- out_unlock:
- inode_unlock(dirp);
- goto out_drop_write;
- }
- static void
- nfsd_close_cached_files(struct dentry *dentry)
- {
- struct inode *inode = d_inode(dentry);
- if (inode && S_ISREG(inode->i_mode))
- nfsd_file_close_inode_sync(inode);
- }
- static bool
- nfsd_has_cached_files(struct dentry *dentry)
- {
- bool ret = false;
- struct inode *inode = d_inode(dentry);
- if (inode && S_ISREG(inode->i_mode))
- ret = nfsd_file_is_cached(inode);
- return ret;
- }
- /*
- * Rename a file
- * N.B. After this call _both_ ffhp and tfhp need an fh_put
- */
- __be32
- nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
- struct svc_fh *tfhp, char *tname, int tlen)
- {
- struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
- struct inode *fdir, *tdir;
- __be32 err;
- int host_err;
- bool close_cached = false;
- err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
- if (err)
- goto out;
- err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
- if (err)
- goto out;
- fdentry = ffhp->fh_dentry;
- fdir = d_inode(fdentry);
- tdentry = tfhp->fh_dentry;
- tdir = d_inode(tdentry);
- err = nfserr_perm;
- if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
- goto out;
- err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
- if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
- goto out;
- if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
- goto out;
- retry:
- host_err = fh_want_write(ffhp);
- if (host_err) {
- err = nfserrno(host_err);
- goto out;
- }
- trap = lock_rename(tdentry, fdentry);
- fh_fill_pre_attrs(ffhp);
- fh_fill_pre_attrs(tfhp);
- odentry = lookup_one_len(fname, fdentry, flen);
- host_err = PTR_ERR(odentry);
- if (IS_ERR(odentry))
- goto out_nfserr;
- host_err = -ENOENT;
- if (d_really_is_negative(odentry))
- goto out_dput_old;
- host_err = -EINVAL;
- if (odentry == trap)
- goto out_dput_old;
- ndentry = lookup_one_len(tname, tdentry, tlen);
- host_err = PTR_ERR(ndentry);
- if (IS_ERR(ndentry))
- goto out_dput_old;
- host_err = -ENOTEMPTY;
- if (ndentry == trap)
- goto out_dput_new;
- if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
- nfsd_has_cached_files(ndentry)) {
- close_cached = true;
- goto out_dput_old;
- } else {
- struct renamedata rd = {
- .old_mnt_userns = &init_user_ns,
- .old_dir = fdir,
- .old_dentry = odentry,
- .new_mnt_userns = &init_user_ns,
- .new_dir = tdir,
- .new_dentry = ndentry,
- };
- int retries;
- for (retries = 1;;) {
- host_err = vfs_rename(&rd);
- if (host_err != -EAGAIN || !retries--)
- break;
- if (!nfsd_wait_for_delegreturn(rqstp, d_inode(odentry)))
- break;
- }
- if (!host_err) {
- host_err = commit_metadata(tfhp);
- if (!host_err)
- host_err = commit_metadata(ffhp);
- }
- }
- out_dput_new:
- dput(ndentry);
- out_dput_old:
- dput(odentry);
- out_nfserr:
- err = nfserrno(host_err);
- if (!close_cached) {
- fh_fill_post_attrs(ffhp);
- fh_fill_post_attrs(tfhp);
- }
- unlock_rename(tdentry, fdentry);
- fh_drop_write(ffhp);
- /*
- * If the target dentry has cached open files, then we need to try to
- * close them prior to doing the rename. Flushing delayed fput
- * shouldn't be done with locks held however, so we delay it until this
- * point and then reattempt the whole shebang.
- */
- if (close_cached) {
- close_cached = false;
- nfsd_close_cached_files(ndentry);
- dput(ndentry);
- goto retry;
- }
- out:
- return err;
- }
- /*
- * Unlink a file or directory
- * N.B. After this call fhp needs an fh_put
- */
- __be32
- nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
- char *fname, int flen)
- {
- struct dentry *dentry, *rdentry;
- struct inode *dirp;
- struct inode *rinode;
- __be32 err;
- int host_err;
- err = nfserr_acces;
- if (!flen || isdotent(fname, flen))
- goto out;
- err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
- if (err)
- goto out;
- host_err = fh_want_write(fhp);
- if (host_err)
- goto out_nfserr;
- dentry = fhp->fh_dentry;
- dirp = d_inode(dentry);
- inode_lock_nested(dirp, I_MUTEX_PARENT);
- rdentry = lookup_one_len(fname, dentry, flen);
- host_err = PTR_ERR(rdentry);
- if (IS_ERR(rdentry))
- goto out_unlock;
- if (d_really_is_negative(rdentry)) {
- dput(rdentry);
- host_err = -ENOENT;
- goto out_unlock;
- }
- rinode = d_inode(rdentry);
- ihold(rinode);
- if (!type)
- type = d_inode(rdentry)->i_mode & S_IFMT;
- fh_fill_pre_attrs(fhp);
- if (type != S_IFDIR) {
- int retries;
- if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
- nfsd_close_cached_files(rdentry);
- for (retries = 1;;) {
- host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
- if (host_err != -EAGAIN || !retries--)
- break;
- if (!nfsd_wait_for_delegreturn(rqstp, rinode))
- break;
- }
- } else {
- host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
- }
- fh_fill_post_attrs(fhp);
- inode_unlock(dirp);
- if (!host_err)
- host_err = commit_metadata(fhp);
- dput(rdentry);
- iput(rinode); /* truncate the inode here */
- out_drop_write:
- fh_drop_write(fhp);
- out_nfserr:
- if (host_err == -EBUSY) {
- /* name is mounted-on. There is no perfect
- * error status.
- */
- if (nfsd_v4client(rqstp))
- err = nfserr_file_open;
- else
- err = nfserr_acces;
- } else {
- err = nfserrno(host_err);
- }
- out:
- return err;
- out_unlock:
- inode_unlock(dirp);
- goto out_drop_write;
- }
- /*
- * We do this buffering because we must not call back into the file
- * system's ->lookup() method from the filldir callback. That may well
- * deadlock a number of file systems.
- *
- * This is based heavily on the implementation of same in XFS.
- */
- struct buffered_dirent {
- u64 ino;
- loff_t offset;
- int namlen;
- unsigned int d_type;
- char name[];
- };
- struct readdir_data {
- struct dir_context ctx;
- char *dirent;
- size_t used;
- int full;
- };
- static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
- int namlen, loff_t offset, u64 ino,
- unsigned int d_type)
- {
- struct readdir_data *buf =
- container_of(ctx, struct readdir_data, ctx);
- struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
- unsigned int reclen;
- reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
- if (buf->used + reclen > PAGE_SIZE) {
- buf->full = 1;
- return false;
- }
- de->namlen = namlen;
- de->offset = offset;
- de->ino = ino;
- de->d_type = d_type;
- memcpy(de->name, name, namlen);
- buf->used += reclen;
- return true;
- }
- static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
- nfsd_filldir_t func, struct readdir_cd *cdp,
- loff_t *offsetp)
- {
- struct buffered_dirent *de;
- int host_err;
- int size;
- loff_t offset;
- struct readdir_data buf = {
- .ctx.actor = nfsd_buffered_filldir,
- .dirent = (void *)__get_free_page(GFP_KERNEL)
- };
- if (!buf.dirent)
- return nfserrno(-ENOMEM);
- offset = *offsetp;
- while (1) {
- unsigned int reclen;
- cdp->err = nfserr_eof; /* will be cleared on successful read */
- buf.used = 0;
- buf.full = 0;
- host_err = iterate_dir(file, &buf.ctx);
- if (buf.full)
- host_err = 0;
- if (host_err < 0)
- break;
- size = buf.used;
- if (!size)
- break;
- de = (struct buffered_dirent *)buf.dirent;
- while (size > 0) {
- offset = de->offset;
- if (func(cdp, de->name, de->namlen, de->offset,
- de->ino, de->d_type))
- break;
- if (cdp->err != nfs_ok)
- break;
- trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
- reclen = ALIGN(sizeof(*de) + de->namlen,
- sizeof(u64));
- size -= reclen;
- de = (struct buffered_dirent *)((char *)de + reclen);
- }
- if (size > 0) /* We bailed out early */
- break;
- offset = vfs_llseek(file, 0, SEEK_CUR);
- }
- free_page((unsigned long)(buf.dirent));
- if (host_err)
- return nfserrno(host_err);
- *offsetp = offset;
- return cdp->err;
- }
- /*
- * Read entries from a directory.
- * The NFSv3/4 verifier we ignore for now.
- */
- __be32
- nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
- struct readdir_cd *cdp, nfsd_filldir_t func)
- {
- __be32 err;
- struct file *file;
- loff_t offset = *offsetp;
- int may_flags = NFSD_MAY_READ;
- /* NFSv2 only supports 32 bit cookies */
- if (rqstp->rq_vers > 2)
- may_flags |= NFSD_MAY_64BIT_COOKIE;
- err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
- if (err)
- goto out;
- offset = vfs_llseek(file, offset, SEEK_SET);
- if (offset < 0) {
- err = nfserrno((int)offset);
- goto out_close;
- }
- err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
- if (err == nfserr_eof || err == nfserr_toosmall)
- err = nfs_ok; /* can still be found in ->err */
- out_close:
- fput(file);
- out:
- return err;
- }
- /*
- * Get file system stats
- * N.B. After this call fhp needs an fh_put
- */
- __be32
- nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
- {
- __be32 err;
- err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
- if (!err) {
- struct path path = {
- .mnt = fhp->fh_export->ex_path.mnt,
- .dentry = fhp->fh_dentry,
- };
- if (vfs_statfs(&path, stat))
- err = nfserr_io;
- }
- return err;
- }
- static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
- {
- return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
- }
- #ifdef CONFIG_NFSD_V4
- /*
- * Helper function to translate error numbers. In the case of xattr operations,
- * some error codes need to be translated outside of the standard translations.
- *
- * ENODATA needs to be translated to nfserr_noxattr.
- * E2BIG to nfserr_xattr2big.
- *
- * Additionally, vfs_listxattr can return -ERANGE. This means that the
- * file has too many extended attributes to retrieve inside an
- * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
- * filesystems will allow the adding of extended attributes until they hit
- * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
- * So, at that point, the attributes are present and valid, but can't
- * be retrieved using listxattr, since the upper level xattr code enforces
- * the XATTR_LIST_MAX limit.
- *
- * This bug means that we need to deal with listxattr returning -ERANGE. The
- * best mapping is to return TOOSMALL.
- */
- static __be32
- nfsd_xattr_errno(int err)
- {
- switch (err) {
- case -ENODATA:
- return nfserr_noxattr;
- case -E2BIG:
- return nfserr_xattr2big;
- case -ERANGE:
- return nfserr_toosmall;
- }
- return nfserrno(err);
- }
- /*
- * Retrieve the specified user extended attribute. To avoid always
- * having to allocate the maximum size (since we are not getting
- * a maximum size from the RPC), do a probe + alloc. Hold a reader
- * lock on i_rwsem to prevent the extended attribute from changing
- * size while we're doing this.
- */
- __be32
- nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
- void **bufp, int *lenp)
- {
- ssize_t len;
- __be32 err;
- char *buf;
- struct inode *inode;
- struct dentry *dentry;
- err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
- if (err)
- return err;
- err = nfs_ok;
- dentry = fhp->fh_dentry;
- inode = d_inode(dentry);
- inode_lock_shared(inode);
- len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
- /*
- * Zero-length attribute, just return.
- */
- if (len == 0) {
- *bufp = NULL;
- *lenp = 0;
- goto out;
- }
- if (len < 0) {
- err = nfsd_xattr_errno(len);
- goto out;
- }
- if (len > *lenp) {
- err = nfserr_toosmall;
- goto out;
- }
- buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
- if (buf == NULL) {
- err = nfserr_jukebox;
- goto out;
- }
- len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
- if (len <= 0) {
- kvfree(buf);
- buf = NULL;
- err = nfsd_xattr_errno(len);
- }
- *lenp = len;
- *bufp = buf;
- out:
- inode_unlock_shared(inode);
- return err;
- }
- /*
- * Retrieve the xattr names. Since we can't know how many are
- * user extended attributes, we must get all attributes here,
- * and have the XDR encode filter out the "user." ones.
- *
- * While this could always just allocate an XATTR_LIST_MAX
- * buffer, that's a waste, so do a probe + allocate. To
- * avoid any changes between the probe and allocate, wrap
- * this in inode_lock.
- */
- __be32
- nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
- int *lenp)
- {
- ssize_t len;
- __be32 err;
- char *buf;
- struct inode *inode;
- struct dentry *dentry;
- err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
- if (err)
- return err;
- dentry = fhp->fh_dentry;
- inode = d_inode(dentry);
- *lenp = 0;
- inode_lock_shared(inode);
- len = vfs_listxattr(dentry, NULL, 0);
- if (len <= 0) {
- err = nfsd_xattr_errno(len);
- goto out;
- }
- if (len > XATTR_LIST_MAX) {
- err = nfserr_xattr2big;
- goto out;
- }
- /*
- * We're holding i_rwsem - use GFP_NOFS.
- */
- buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
- if (buf == NULL) {
- err = nfserr_jukebox;
- goto out;
- }
- len = vfs_listxattr(dentry, buf, len);
- if (len <= 0) {
- kvfree(buf);
- err = nfsd_xattr_errno(len);
- goto out;
- }
- *lenp = len;
- *bufp = buf;
- err = nfs_ok;
- out:
- inode_unlock_shared(inode);
- return err;
- }
- /**
- * nfsd_removexattr - Remove an extended attribute
- * @rqstp: RPC transaction being executed
- * @fhp: NFS filehandle of object with xattr to remove
- * @name: name of xattr to remove (NUL-terminate)
- *
- * Pass in a NULL pointer for delegated_inode, and let the client deal
- * with NFS4ERR_DELAY (same as with e.g. setattr and remove).
- *
- * Returns nfs_ok on success, or an nfsstat in network byte order.
- */
- __be32
- nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
- {
- __be32 err;
- int ret;
- err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
- if (err)
- return err;
- ret = fh_want_write(fhp);
- if (ret)
- return nfserrno(ret);
- inode_lock(fhp->fh_dentry->d_inode);
- fh_fill_pre_attrs(fhp);
- ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
- name, NULL);
- fh_fill_post_attrs(fhp);
- inode_unlock(fhp->fh_dentry->d_inode);
- fh_drop_write(fhp);
- return nfsd_xattr_errno(ret);
- }
- __be32
- nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
- void *buf, u32 len, u32 flags)
- {
- __be32 err;
- int ret;
- err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
- if (err)
- return err;
- ret = fh_want_write(fhp);
- if (ret)
- return nfserrno(ret);
- inode_lock(fhp->fh_dentry->d_inode);
- fh_fill_pre_attrs(fhp);
- ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
- len, flags, NULL);
- fh_fill_post_attrs(fhp);
- inode_unlock(fhp->fh_dentry->d_inode);
- fh_drop_write(fhp);
- return nfsd_xattr_errno(ret);
- }
- #endif
- /*
- * Check for a user's access permissions to this inode.
- */
- __be32
- nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
- struct dentry *dentry, int acc)
- {
- struct inode *inode = d_inode(dentry);
- int err;
- if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
- return 0;
- #if 0
- dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
- acc,
- (acc & NFSD_MAY_READ)? " read" : "",
- (acc & NFSD_MAY_WRITE)? " write" : "",
- (acc & NFSD_MAY_EXEC)? " exec" : "",
- (acc & NFSD_MAY_SATTR)? " sattr" : "",
- (acc & NFSD_MAY_TRUNC)? " trunc" : "",
- (acc & NFSD_MAY_LOCK)? " lock" : "",
- (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
- inode->i_mode,
- IS_IMMUTABLE(inode)? " immut" : "",
- IS_APPEND(inode)? " append" : "",
- __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
- dprintk(" owner %d/%d user %d/%d\n",
- inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
- #endif
- /* Normally we reject any write/sattr etc access on a read-only file
- * system. But if it is IRIX doing check on write-access for a
- * device special file, we ignore rofs.
- */
- if (!(acc & NFSD_MAY_LOCAL_ACCESS))
- if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
- if (exp_rdonly(rqstp, exp) ||
- __mnt_is_readonly(exp->ex_path.mnt))
- return nfserr_rofs;
- if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
- return nfserr_perm;
- }
- if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
- return nfserr_perm;
- if (acc & NFSD_MAY_LOCK) {
- /* If we cannot rely on authentication in NLM requests,
- * just allow locks, otherwise require read permission, or
- * ownership
- */
- if (exp->ex_flags & NFSEXP_NOAUTHNLM)
- return 0;
- else
- acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
- }
- /*
- * The file owner always gets access permission for accesses that
- * would normally be checked at open time. This is to make
- * file access work even when the client has done a fchmod(fd, 0).
- *
- * However, `cp foo bar' should fail nevertheless when bar is
- * readonly. A sensible way to do this might be to reject all
- * attempts to truncate a read-only file, because a creat() call
- * always implies file truncation.
- * ... but this isn't really fair. A process may reasonably call
- * ftruncate on an open file descriptor on a file with perm 000.
- * We must trust the client to do permission checking - using "ACCESS"
- * with NFSv3.
- */
- if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
- uid_eq(inode->i_uid, current_fsuid()))
- return 0;
- /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
- err = inode_permission(&init_user_ns, inode,
- acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
- /* Allow read access to binaries even when mode 111 */
- if (err == -EACCES && S_ISREG(inode->i_mode) &&
- (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
- acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
- err = inode_permission(&init_user_ns, inode, MAY_EXEC);
- return err? nfserrno(err) : 0;
- }
|