v4.19.13 snapshot.
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
new file mode 100644
index 0000000..b53e763
--- /dev/null
+++ b/fs/nfsd/vfs.c
@@ -0,0 +1,2116 @@
+// 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 <okir@monad.swb.de>
+ * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
+ */
+
+#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/slab.h>
+#include <linux/uaccess.h>
+#include <linux/exportfs.h>
+#include <linux/writeback.h>
+#include <linux/security.h>
+
+#ifdef CONFIG_NFSD_V3
+#include "xdr3.h"
+#endif /* CONFIG_NFSD_V3 */
+
+#ifdef CONFIG_NFSD_V4
+#include "../internal.h"
+#include "acl.h"
+#include "idmap.h"
+#endif /* CONFIG_NFSD_V4 */
+
+#include "nfsd.h"
+#include "vfs.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY NFSDDBG_FILEOP
+
+
+/*
+ * This is a cache of readahead params that help us choose the proper
+ * readahead strategy. Initially, we set all readahead parameters to 0
+ * and let the VFS handle things.
+ * If you increase the number of cached files very much, you'll need to
+ * add a hash table here.
+ */
+struct raparms {
+ struct raparms *p_next;
+ unsigned int p_count;
+ ino_t p_ino;
+ dev_t p_dev;
+ int p_set;
+ struct file_ra_state p_ra;
+ unsigned int p_hindex;
+};
+
+struct raparm_hbucket {
+ struct raparms *pb_head;
+ spinlock_t pb_lock;
+} ____cacheline_aligned_in_smp;
+
+#define RAPARM_HASH_BITS 4
+#define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
+#define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
+static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
+
+/*
+ * 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 {
+ /*
+ * In the nfsd4_open() case, this may be held across
+ * subsequent open and delegation acquisition which may
+ * need to take the child's i_mutex:
+ */
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
+ dentry = lookup_one_len(name, dparent, len);
+ host_err = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto out_nfserr;
+ if (nfsd_mountpoint(dentry, exp)) {
+ /*
+ * We don't need the i_mutex after all. It's
+ * still possible we could open this (regular
+ * files can be mountpoints too), but the
+ * i_mutex is just there to prevent renames of
+ * something that we might be about to delegate,
+ * and a mountpoint won't be renamed:
+ */
+ fh_unlock(fhp);
+ if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
+ dput(dentry);
+ goto out_nfserr;
+ }
+ }
+ }
+ *dentry_ret = dentry;
+ *exp_ret = exp;
+ return 0;
+
+out_nfserr:
+ exp_put(exp);
+ return nfserrno(host_err);
+}
+
+/*
+ * 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
+ * NeilBrown <neilb@cse.unsw.edu.au>
+ */
+__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_metadata(struct svc_fh *fhp)
+{
+ struct inode *inode = d_inode(fhp->fh_dentry);
+ const struct export_operations *export_ops = inode->i_sb->s_export_op;
+
+ if (!EX_ISSYNC(fhp->fh_export))
+ return 0;
+
+ if (export_ops->commit_metadata)
+ return export_ops->commit_metadata(inode);
+ return sync_inode_metadata(inode, 1);
+}
+
+/*
+ * 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)
+{
+ /* 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 | ATTR_KILL_SGID);
+ }
+ }
+}
+
+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);
+ int host_err;
+
+ 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;
+ }
+
+ host_err = get_write_access(inode);
+ if (host_err)
+ goto out_nfserrno;
+
+ host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
+ if (host_err)
+ goto out_put_write_access;
+ return 0;
+
+out_put_write_access:
+ put_write_access(inode);
+out_nfserrno:
+ return nfserrno(host_err);
+}
+
+/*
+ * Set various file attributes. After this call fhp needs an fh_put.
+ */
+__be32
+nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
+ int check_guard, time_t guardtime)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+ 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);
+
+ if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
+ accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
+ if (iap->ia_valid & ATTR_SIZE)
+ ftype = S_IFREG;
+
+ /* 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);
+
+ /* Ignore any mode updates on symlinks */
+ if (S_ISLNK(inode->i_mode))
+ iap->ia_valid &= ~ATTR_MODE;
+
+ if (!iap->ia_valid)
+ return 0;
+
+ 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;
+ }
+
+ fh_lock(fhp);
+ if (size_change) {
+ /*
+ * 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,
+ };
+
+ host_err = notify_change(dentry, &size_attr, NULL);
+ if (host_err)
+ goto out_unlock;
+ 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)
+ goto out_unlock;
+ }
+
+ iap->ia_valid |= ATTR_CTIME;
+ host_err = notify_change(dentry, iap, NULL);
+
+out_unlock:
+ fh_unlock(fhp);
+ 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(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
+ return 0;
+ return 1;
+}
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ struct xdr_netobj *label)
+{
+ __be32 error;
+ int host_error;
+ struct dentry *dentry;
+
+ error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
+ if (error)
+ return error;
+
+ dentry = fhp->fh_dentry;
+
+ inode_lock(d_inode(dentry));
+ host_error = security_inode_setsecctx(dentry, label->data, label->len);
+ inode_unlock(d_inode(dentry));
+ return nfserrno(host_error);
+}
+#else
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ struct xdr_netobj *label)
+{
+ return nfserr_notsupp;
+}
+#endif
+
+__be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
+ u64 dst_pos, u64 count)
+{
+ return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos,
+ count));
+}
+
+ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
+ u64 dst_pos, u64 count)
+{
+
+ /*
+ * 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);
+ return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+}
+
+__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) */
+
+#ifdef CONFIG_NFSD_V3
+/*
+ * 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 },
+
+ { 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 },
+
+ { 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;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+static 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
+ */
+__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;
+
+ 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;
+ err = fh_verify(rqstp, fhp, type, may_flags);
+ if (err)
+ goto out;
+
+ path.mnt = fhp->fh_export->ex_path.mnt;
+ path.dentry = fhp->fh_dentry;
+ inode = d_inode(path.dentry);
+
+ /* Disallow write access to files with the append-only bit set
+ * or any access when mandatory locking enabled
+ */
+ err = nfserr_perm;
+ if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
+ goto out;
+ /*
+ * We must ignore files (but only files) which might have mandatory
+ * locks on them because there is no way to know if the accesser has
+ * the lock.
+ */
+ if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
+ 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:
+ validate_process_creds();
+ return err;
+}
+
+struct raparms *
+nfsd_init_raparms(struct file *file)
+{
+ struct inode *inode = file_inode(file);
+ dev_t dev = inode->i_sb->s_dev;
+ ino_t ino = inode->i_ino;
+ struct raparms *ra, **rap, **frap = NULL;
+ int depth = 0;
+ unsigned int hash;
+ struct raparm_hbucket *rab;
+
+ hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
+ rab = &raparm_hash[hash];
+
+ spin_lock(&rab->pb_lock);
+ for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
+ if (ra->p_ino == ino && ra->p_dev == dev)
+ goto found;
+ depth++;
+ if (ra->p_count == 0)
+ frap = rap;
+ }
+ depth = nfsdstats.ra_size;
+ if (!frap) {
+ spin_unlock(&rab->pb_lock);
+ return NULL;
+ }
+ rap = frap;
+ ra = *frap;
+ ra->p_dev = dev;
+ ra->p_ino = ino;
+ ra->p_set = 0;
+ ra->p_hindex = hash;
+found:
+ if (rap != &rab->pb_head) {
+ *rap = ra->p_next;
+ ra->p_next = rab->pb_head;
+ rab->pb_head = ra;
+ }
+ ra->p_count++;
+ nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
+ spin_unlock(&rab->pb_lock);
+
+ if (ra->p_set)
+ file->f_ra = ra->p_ra;
+ return ra;
+}
+
+void nfsd_put_raparams(struct file *file, struct raparms *ra)
+{
+ struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
+
+ spin_lock(&rab->pb_lock);
+ ra->p_ra = file->f_ra;
+ ra->p_set = 1;
+ ra->p_count--;
+ spin_unlock(&rab->pb_lock);
+}
+
+/*
+ * 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 **pp = rqstp->rq_next_page;
+ struct page *page = buf->page;
+ size_t size;
+
+ size = sd->len;
+
+ if (rqstp->rq_res.page_len == 0) {
+ get_page(page);
+ put_page(*rqstp->rq_next_page);
+ *(rqstp->rq_next_page++) = page;
+ rqstp->rq_res.page_base = buf->offset;
+ rqstp->rq_res.page_len = size;
+ } else if (page != pp[-1]) {
+ get_page(page);
+ if (*rqstp->rq_next_page)
+ put_page(*rqstp->rq_next_page);
+ *(rqstp->rq_next_page++) = page;
+ rqstp->rq_res.page_len += size;
+ } else
+ rqstp->rq_res.page_len += size;
+
+ return size;
+}
+
+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 __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ struct file *file, loff_t offset,
+ unsigned long *count, int host_err)
+{
+ if (host_err >= 0) {
+ nfsdstats.io_read += host_err;
+ *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)
+{
+ struct splice_desc sd = {
+ .len = 0,
+ .total_len = *count,
+ .pos = offset,
+ .u.data = rqstp,
+ };
+ int 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, 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)
+{
+ struct iov_iter iter;
+ int host_err;
+
+ trace_nfsd_read_vector(rqstp, fhp, offset, *count);
+ iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
+ host_err = vfs_iter_read(file, &iter, &offset, 0);
+ return nfsd_finish_read(rqstp, fhp, file, offset, count, 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 file *file,
+ loff_t offset, struct kvec *vec, int vlen,
+ unsigned long *cnt, int stable)
+{
+ struct svc_export *exp;
+ struct iov_iter iter;
+ __be32 nfserr;
+ int host_err;
+ int use_wgather;
+ loff_t pos = offset;
+ unsigned int pflags = current->flags;
+ rwf_t flags = 0;
+
+ trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
+
+ if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
+ /*
+ * We want less throttling in balance_dirty_pages()
+ * and shrink_inactive_list() 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_LESS_THROTTLE;
+
+ 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, WRITE | ITER_KVEC, vec, vlen, *cnt);
+ host_err = vfs_iter_write(file, &iter, &pos, flags);
+ if (host_err < 0)
+ goto out_nfserr;
+ nfsdstats.io_write += *cnt;
+ fsnotify_modify(file);
+
+ if (stable && use_wgather)
+ host_err = wait_for_concurrent_writes(file);
+
+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 (test_bit(RQ_LOCAL, &rqstp->rq_flags))
+ current_restore_flags(pflags, PF_LESS_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)
+{
+ struct file *file;
+ struct raparms *ra;
+ __be32 err;
+
+ trace_nfsd_read_start(rqstp, fhp, offset, *count);
+ err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
+ if (err)
+ return err;
+
+ ra = nfsd_init_raparms(file);
+
+ if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
+ err = nfsd_splice_read(rqstp, fhp, file, offset, count);
+ else
+ err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count);
+
+ if (ra)
+ nfsd_put_raparams(file, ra);
+ fput(file);
+
+ 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)
+{
+ struct file *file = NULL;
+ __be32 err = 0;
+
+ trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
+
+ err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
+ if (err)
+ goto out;
+
+ err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stable);
+ fput(file);
+out:
+ trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
+ return err;
+}
+
+#ifdef CONFIG_NFSD_V3
+/*
+ * Commit all pending writes to stable storage.
+ *
+ * Note: we only guarantee that data that lies within the range specified
+ * by the 'offset' and 'count' parameters will be synced.
+ *
+ * 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.
+ */
+__be32
+nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ loff_t offset, unsigned long count)
+{
+ struct file *file;
+ loff_t end = LLONG_MAX;
+ __be32 err = nfserr_inval;
+
+ if (offset < 0)
+ goto out;
+ if (count != 0) {
+ end = offset + (loff_t)count - 1;
+ if (end < offset)
+ goto out;
+ }
+
+ err = nfsd_open(rqstp, fhp, S_IFREG,
+ NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
+ if (err)
+ goto out;
+ if (EX_ISSYNC(fhp->fh_export)) {
+ int err2 = vfs_fsync_range(file, offset, end, 0);
+
+ if (err2 != -EINVAL)
+ err = nfserrno(err2);
+ else
+ err = nfserr_notsupp;
+ }
+
+ fput(file);
+out:
+ return err;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+static __be32
+nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
+ struct iattr *iap)
+{
+ /*
+ * Mode has already been set earlier in create:
+ */
+ 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);
+ if (iap->ia_valid)
+ return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
+ /* Callers expect file metadata to be committed here */
+ return nfserrno(commit_metadata(resfhp));
+}
+
+/* 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,
+ char *fname, int flen, struct iattr *iap,
+ int type, dev_t rdev, struct svc_fh *resfhp)
+{
+ struct dentry *dentry, *dchild;
+ struct inode *dirp;
+ __be32 err;
+ __be32 err2;
+ int host_err;
+
+ dentry = fhp->fh_dentry;
+ dirp = d_inode(dentry);
+
+ dchild = dget(resfhp->fh_dentry);
+ if (!fhp->fh_locked) {
+ WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
+ dentry);
+ err = nfserr_io;
+ goto out;
+ }
+
+ 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;
+
+ err = 0;
+ host_err = 0;
+ switch (type) {
+ case S_IFREG:
+ host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
+ if (!host_err)
+ nfsd_check_ignore_resizing(iap);
+ break;
+ case S_IFDIR:
+ host_err = vfs_mkdir(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(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, resfhp, iap);
+
+ /*
+ * nfsd_create_setattr already committed the child. Transactional
+ * filesystems had a chance to commit changes for both parent and
+ * child simultaneously making the following commit_metadata a
+ * noop.
+ */
+ err2 = nfserrno(commit_metadata(fhp));
+ if (err2)
+ err = err2;
+ /*
+ * Update the file handle to get the new inode info.
+ */
+ if (!err)
+ err = fh_update(resfhp);
+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 iattr *iap,
+ int type, dev_t rdev, struct svc_fh *resfhp)
+{
+ struct dentry *dentry, *dchild = NULL;
+ struct inode *dirp;
+ __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;
+ dirp = d_inode(dentry);
+
+ host_err = fh_want_write(fhp);
+ if (host_err)
+ return nfserrno(host_err);
+
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
+ dchild = lookup_one_len(fname, dentry, flen);
+ host_err = PTR_ERR(dchild);
+ if (IS_ERR(dchild))
+ return nfserrno(host_err);
+ 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)
+ return err;
+ return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
+ rdev, resfhp);
+}
+
+#ifdef CONFIG_NFSD_V3
+
+/*
+ * NFSv3 and NFSv4 version of nfsd_create
+ */
+__be32
+do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ char *fname, int flen, struct iattr *iap,
+ struct svc_fh *resfhp, int createmode, u32 *verifier,
+ bool *truncp, bool *created)
+{
+ struct dentry *dentry, *dchild = NULL;
+ struct inode *dirp;
+ __be32 err;
+ int host_err;
+ __u32 v_mtime=0, v_atime=0;
+
+ err = nfserr_perm;
+ if (!flen)
+ goto out;
+ err = nfserr_exist;
+ if (isdotent(fname, flen))
+ goto out;
+ if (!(iap->ia_valid & ATTR_MODE))
+ iap->ia_mode = 0;
+ err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+ if (err)
+ goto out;
+
+ dentry = fhp->fh_dentry;
+ dirp = d_inode(dentry);
+
+ host_err = fh_want_write(fhp);
+ if (host_err)
+ goto out_nfserr;
+
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
+
+ /*
+ * Compose the response file handle.
+ */
+ dchild = lookup_one_len(fname, dentry, flen);
+ host_err = PTR_ERR(dchild);
+ if (IS_ERR(dchild))
+ goto out_nfserr;
+
+ /* If file doesn't exist, check for permissions to create one */
+ if (d_really_is_negative(dchild)) {
+ err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+ if (err)
+ goto out;
+ }
+
+ err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+ if (err)
+ goto out;
+
+ if (nfsd_create_is_exclusive(createmode)) {
+ /* solaris7 gets confused (bugid 4218508) if these have
+ * the high bit set, so just clear the high bits. If this is
+ * ever changed to use different attrs for storing the
+ * verifier, then do_open_lookup() will also need to be fixed
+ * accordingly.
+ */
+ v_mtime = verifier[0]&0x7fffffff;
+ v_atime = verifier[1]&0x7fffffff;
+ }
+
+ if (d_really_is_positive(dchild)) {
+ err = 0;
+
+ switch (createmode) {
+ case NFS3_CREATE_UNCHECKED:
+ if (! d_is_reg(dchild))
+ goto out;
+ else if (truncp) {
+ /* in nfsv4, we need to treat this case a little
+ * differently. we don't want to truncate the
+ * file now; this would be wrong if the OPEN
+ * fails for some other reason. furthermore,
+ * if the size is nonzero, we should ignore it
+ * according to spec!
+ */
+ *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
+ }
+ else {
+ iap->ia_valid &= ATTR_SIZE;
+ goto set_attr;
+ }
+ break;
+ case NFS3_CREATE_EXCLUSIVE:
+ if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
+ && d_inode(dchild)->i_atime.tv_sec == v_atime
+ && d_inode(dchild)->i_size == 0 ) {
+ if (created)
+ *created = 1;
+ break;
+ }
+ case NFS4_CREATE_EXCLUSIVE4_1:
+ if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
+ && d_inode(dchild)->i_atime.tv_sec == v_atime
+ && d_inode(dchild)->i_size == 0 ) {
+ if (created)
+ *created = 1;
+ goto set_attr;
+ }
+ /* fallthru */
+ case NFS3_CREATE_GUARDED:
+ err = nfserr_exist;
+ }
+ fh_drop_write(fhp);
+ goto out;
+ }
+
+ host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
+ if (host_err < 0) {
+ fh_drop_write(fhp);
+ goto out_nfserr;
+ }
+ if (created)
+ *created = 1;
+
+ nfsd_check_ignore_resizing(iap);
+
+ if (nfsd_create_is_exclusive(createmode)) {
+ /* Cram the verifier into atime/mtime */
+ iap->ia_valid = ATTR_MTIME|ATTR_ATIME
+ | ATTR_MTIME_SET|ATTR_ATIME_SET;
+ /* XXX someone who knows this better please fix it for nsec */
+ iap->ia_mtime.tv_sec = v_mtime;
+ iap->ia_atime.tv_sec = v_atime;
+ iap->ia_mtime.tv_nsec = 0;
+ iap->ia_atime.tv_nsec = 0;
+ }
+
+ set_attr:
+ err = nfsd_create_setattr(rqstp, resfhp, iap);
+
+ /*
+ * nfsd_create_setattr already committed the child
+ * (and possibly also the parent).
+ */
+ if (!err)
+ err = nfserrno(commit_metadata(fhp));
+
+ /*
+ * Update the filehandle to get the new inode info.
+ */
+ if (!err)
+ err = fh_update(resfhp);
+
+ out:
+ fh_unlock(fhp);
+ if (dchild && !IS_ERR(dchild))
+ dput(dchild);
+ fh_drop_write(fhp);
+ return err;
+
+ out_nfserr:
+ err = nfserrno(host_err);
+ goto out;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+/*
+ * 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;
+}
+
+/*
+ * Create a symlink and look up its inode
+ * N.B. After this call _both_ fhp and resfhp need an fh_put
+ */
+__be32
+nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ char *fname, int flen,
+ char *path,
+ 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)
+ goto out_nfserr;
+
+ fh_lock(fhp);
+ dentry = fhp->fh_dentry;
+ dnew = lookup_one_len(fname, dentry, flen);
+ host_err = PTR_ERR(dnew);
+ if (IS_ERR(dnew))
+ goto out_nfserr;
+
+ host_err = vfs_symlink(d_inode(dentry), dnew, path);
+ err = nfserrno(host_err);
+ if (!err)
+ err = nfserrno(commit_metadata(fhp));
+ fh_unlock(fhp);
+
+ fh_drop_write(fhp);
+
+ cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
+ dput(dnew);
+ if (err==0) err = cerr;
+out:
+ return err;
+
+out_nfserr:
+ err = nfserrno(host_err);
+ goto out;
+}
+
+/*
+ * 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;
+ }
+
+ fh_lock_nested(ffhp, I_MUTEX_PARENT);
+ ddir = ffhp->fh_dentry;
+ dirp = d_inode(ddir);
+
+ dnew = lookup_one_len(name, ddir, len);
+ host_err = PTR_ERR(dnew);
+ if (IS_ERR(dnew))
+ goto out_nfserr;
+
+ dold = tfhp->fh_dentry;
+
+ err = nfserr_noent;
+ if (d_really_is_negative(dold))
+ goto out_dput;
+ host_err = vfs_link(dold, dirp, dnew, NULL);
+ 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);
+ }
+out_dput:
+ dput(dnew);
+out_unlock:
+ fh_unlock(ffhp);
+ fh_drop_write(tfhp);
+out:
+ return err;
+
+out_nfserr:
+ err = nfserrno(host_err);
+ goto out_unlock;
+}
+
+/*
+ * 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;
+
+ 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;
+
+ host_err = fh_want_write(ffhp);
+ if (host_err) {
+ err = nfserrno(host_err);
+ goto out;
+ }
+
+ /* cannot use fh_lock as we need deadlock protective ordering
+ * so do it by hand */
+ trap = lock_rename(tdentry, fdentry);
+ ffhp->fh_locked = tfhp->fh_locked = true;
+ fill_pre_wcc(ffhp);
+ fill_pre_wcc(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;
+
+ host_err = -EXDEV;
+ if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+ goto out_dput_new;
+ if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
+ goto out_dput_new;
+
+ host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
+ 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);
+ /*
+ * We cannot rely on fh_unlock on the two filehandles,
+ * as that would do the wrong thing if the two directories
+ * were the same, so again we do it by hand.
+ */
+ fill_post_wcc(ffhp);
+ fill_post_wcc(tfhp);
+ unlock_rename(tdentry, fdentry);
+ ffhp->fh_locked = tfhp->fh_locked = false;
+ fh_drop_write(ffhp);
+
+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;
+ __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;
+
+ fh_lock_nested(fhp, I_MUTEX_PARENT);
+ dentry = fhp->fh_dentry;
+ dirp = d_inode(dentry);
+
+ rdentry = lookup_one_len(fname, dentry, flen);
+ host_err = PTR_ERR(rdentry);
+ if (IS_ERR(rdentry))
+ goto out_nfserr;
+
+ if (d_really_is_negative(rdentry)) {
+ dput(rdentry);
+ err = nfserr_noent;
+ goto out;
+ }
+
+ if (!type)
+ type = d_inode(rdentry)->i_mode & S_IFMT;
+
+ if (type != S_IFDIR)
+ host_err = vfs_unlink(dirp, rdentry, NULL);
+ else
+ host_err = vfs_rmdir(dirp, rdentry);
+ if (!host_err)
+ host_err = commit_metadata(fhp);
+ dput(rdentry);
+
+out_nfserr:
+ err = nfserrno(host_err);
+out:
+ return err;
+}
+
+/*
+ * 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 int 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 -EINVAL;
+ }
+
+ de->namlen = namlen;
+ de->offset = offset;
+ de->ino = ino;
+ de->d_type = d_type;
+ memcpy(de->name, name, namlen);
+ buf->used += reclen;
+
+ return 0;
+}
+
+static __be32 nfsd_buffered_readdir(struct file *file, 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;
+
+ 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, 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;
+}
+
+/*
+ * 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(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(inode, MAY_EXEC);
+
+ return err? nfserrno(err) : 0;
+}
+
+void
+nfsd_racache_shutdown(void)
+{
+ struct raparms *raparm, *last_raparm;
+ unsigned int i;
+
+ dprintk("nfsd: freeing readahead buffers.\n");
+
+ for (i = 0; i < RAPARM_HASH_SIZE; i++) {
+ raparm = raparm_hash[i].pb_head;
+ while(raparm) {
+ last_raparm = raparm;
+ raparm = raparm->p_next;
+ kfree(last_raparm);
+ }
+ raparm_hash[i].pb_head = NULL;
+ }
+}
+/*
+ * Initialize readahead param cache
+ */
+int
+nfsd_racache_init(int cache_size)
+{
+ int i;
+ int j = 0;
+ int nperbucket;
+ struct raparms **raparm = NULL;
+
+
+ if (raparm_hash[0].pb_head)
+ return 0;
+ nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
+ nperbucket = max(2, nperbucket);
+ cache_size = nperbucket * RAPARM_HASH_SIZE;
+
+ dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
+
+ for (i = 0; i < RAPARM_HASH_SIZE; i++) {
+ spin_lock_init(&raparm_hash[i].pb_lock);
+
+ raparm = &raparm_hash[i].pb_head;
+ for (j = 0; j < nperbucket; j++) {
+ *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
+ if (!*raparm)
+ goto out_nomem;
+ raparm = &(*raparm)->p_next;
+ }
+ *raparm = NULL;
+ }
+
+ nfsdstats.ra_size = cache_size;
+ return 0;
+
+out_nomem:
+ dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
+ nfsd_racache_shutdown();
+ return -ENOMEM;
+}