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LeafOS / LeafOS-Devices / android_kernel_samsung_exynos9820 / a16877ca9cec211708a161057a7cbfbf2cbc3a53 / . / fs / nfsd / vfs.c
blob: 9152f87eea1896ca276c40cd741cd42f434c016f [file] [log] [blame]
#define MSNFS /* HACK HACK */
/*
* linux/fs/nfsd/vfs.c
*
* 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/string.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/major.h>
#include <linux/splice.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/in.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/delay.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#ifdef CONFIG_NFSD_V3
#include <linux/nfs3.h>
#include <linux/nfsd/xdr3.h>
#endif /* CONFIG_NFSD_V3 */
#include <linux/nfsd/nfsfh.h>
#include <linux/quotaops.h>
#include <linux/fsnotify.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
#ifdef CONFIG_NFSD_V4
#include <linux/nfs4.h>
#include <linux/nfs4_acl.h>
#include <linux/nfsd_idmap.h>
#include <linux/security.h>
#endif /* CONFIG_NFSD_V4 */
#include <linux/jhash.h>
#include <asm/uaccess.h>
#define NFSDDBG_FACILITY NFSDDBG_FILEOP
/* 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.
*/
#define IS_ISMNDLK(i) (S_ISREG((i)->i_mode) && mandatory_lock(i))
/*
* 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;
static struct raparms * raparml;
#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 vfsmount *mnt = mntget(exp->ex_mnt);
struct dentry *mounts = dget(dentry);
int err = 0;
while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));
exp2 = rqst_exp_get_by_name(rqstp, mnt, mounts);
if (IS_ERR(exp2)) {
if (PTR_ERR(exp2) != -ENOENT)
err = PTR_ERR(exp2);
dput(mounts);
mntput(mnt);
goto out;
}
if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
/* successfully crossed mount point */
exp_put(exp);
*expp = exp2;
dput(dentry);
*dpp = mounts;
} else {
exp_put(exp2);
dput(mounts);
}
mntput(mnt);
out:
return err;
}
__be32
nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
const char *name, int len,
struct svc_export **exp_ret, struct dentry **dentry_ret)
{
struct svc_export *exp;
struct dentry *dparent;
struct dentry *dentry;
__be32 err;
int host_err;
dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
/* Obtain dentry and export. */
err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
if (err)
return err;
dparent = fhp->fh_dentry;
exp = fhp->fh_export;
exp_get(exp);
/* Lookup the name, but don't follow links */
if (isdotent(name, len)) {
if (len==1)
dentry = dget(dparent);
else if (dparent != exp->ex_dentry) {
dentry = dget_parent(dparent);
} else if (!EX_NOHIDE(exp))
dentry = dget(dparent); /* .. == . just like at / */
else {
/* checking mountpoint crossing is very different when stepping up */
struct svc_export *exp2 = NULL;
struct dentry *dp;
struct vfsmount *mnt = mntget(exp->ex_mnt);
dentry = dget(dparent);
while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
;
dp = dget_parent(dentry);
dput(dentry);
dentry = dp;
exp2 = rqst_exp_parent(rqstp, mnt, dentry);
if (PTR_ERR(exp2) == -ENOENT) {
dput(dentry);
dentry = dget(dparent);
} else if (IS_ERR(exp2)) {
host_err = PTR_ERR(exp2);
dput(dentry);
mntput(mnt);
goto out_nfserr;
} else {
exp_put(exp);
exp = exp2;
}
mntput(mnt);
}
} else {
fh_lock(fhp);
dentry = lookup_one_len(name, dparent, len);
host_err = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_nfserr;
/*
* check if we have crossed a mount point ...
*/
if (d_mountpoint(dentry)) {
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,
int len, struct svc_fh *resfh)
{
struct svc_export *exp;
struct dentry *dentry;
__be32 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 && !dentry->d_inode)
err = nfserr_noent;
out:
dput(dentry);
exp_put(exp);
return err;
}
/*
* Set various file attributes.
* N.B. 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 = MAY_SATTR;
int ftype = 0;
int imode;
__be32 err;
int host_err;
int size_change = 0;
if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE;
if (iap->ia_valid & ATTR_SIZE)
ftype = S_IFREG;
/* Get inode */
err = fh_verify(rqstp, fhp, ftype, accmode);
if (err)
goto out;
dentry = fhp->fh_dentry;
inode = dentry->d_inode;
/* Ignore any mode updates on symlinks */
if (S_ISLNK(inode->i_mode))
iap->ia_valid &= ~ATTR_MODE;
if (!iap->ia_valid)
goto out;
/* NFSv2 does not differentiate between "set-[ac]time-to-now"
* which only requires access, and "set-[ac]time-to-X" which
* requires ownership.
* So if it looks like it might be "set both to the same time which
* is close to now", and if inode_change_ok fails, then we
* convert to "set to now" instead of "set to explicit time"
*
* We only call inode_change_ok as the last test as technically
* it is not an interface that we should be using. It is only
* valid if the filesystem does not define it's own i_op->setattr.
*/
#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
#define MAX_TOUCH_TIME_ERROR (30*60)
if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET
&& iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec
) {
/* Looks probable. Now just make sure time is in the right ballpark.
* Solaris, at least, doesn't seem to care what the time request is.
* We require it be within 30 minutes of now.
*/
time_t delta = iap->ia_atime.tv_sec - get_seconds();
if (delta<0) delta = -delta;
if (delta < MAX_TOUCH_TIME_ERROR &&
inode_change_ok(inode, iap) != 0) {
/* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME
* this will cause notify_change to set these times to "now"
*/
iap->ia_valid &= ~BOTH_TIME_SET;
}
}
/* The size case is special. It changes the file as well as the attributes. */
if (iap->ia_valid & ATTR_SIZE) {
if (iap->ia_size < inode->i_size) {
err = nfsd_permission(rqstp, fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
if (err)
goto out;
}
/*
* If we are changing the size of the file, then
* we need to break all leases.
*/
host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
if (host_err == -EWOULDBLOCK)
host_err = -ETIMEDOUT;
if (host_err) /* ENOMEM or EWOULDBLOCK */
goto out_nfserr;
host_err = get_write_access(inode);
if (host_err)
goto out_nfserr;
size_change = 1;
host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
if (host_err) {
put_write_access(inode);
goto out_nfserr;
}
DQUOT_INIT(inode);
}
imode = inode->i_mode;
if (iap->ia_valid & ATTR_MODE) {
iap->ia_mode &= S_IALLUGO;
imode = iap->ia_mode |= (imode & ~S_IALLUGO);
}
/* Revoke setuid/setgid bit on chown/chgrp */
if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
iap->ia_valid |= ATTR_KILL_SUID;
if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
iap->ia_valid |= ATTR_KILL_SGID;
/* Change the attributes. */
iap->ia_valid |= ATTR_CTIME;
err = nfserr_notsync;
if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
fh_lock(fhp);
host_err = notify_change(dentry, iap);
err = nfserrno(host_err);
fh_unlock(fhp);
}
if (size_change)
put_write_access(inode);
if (!err)
if (EX_ISSYNC(fhp->fh_export))
write_inode_now(inode, 1);
out:
return err;
out_nfserr:
err = nfserrno(host_err);
goto out;
}
#if defined(CONFIG_NFSD_V2_ACL) || \
defined(CONFIG_NFSD_V3_ACL) || \
defined(CONFIG_NFSD_V4)
static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
{
ssize_t buflen;
buflen = vfs_getxattr(dentry, key, NULL, 0);
if (buflen <= 0)
return buflen;
*buf = kmalloc(buflen, GFP_KERNEL);
if (!*buf)
return -ENOMEM;
return vfs_getxattr(dentry, key, *buf, buflen);
}
#endif
#if defined(CONFIG_NFSD_V4)
static int
set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
{
int len;
size_t buflen;
char *buf = NULL;
int error = 0;
buflen = posix_acl_xattr_size(pacl->a_count);
buf = kmalloc(buflen, GFP_KERNEL);
error = -ENOMEM;
if (buf == NULL)
goto out;
len = posix_acl_to_xattr(pacl, buf, buflen);
if (len < 0) {
error = len;
goto out;
}
error = vfs_setxattr(dentry, key, buf, len, 0);
out:
kfree(buf);
return error;
}
__be32
nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct nfs4_acl *acl)
{
__be32 error;
int host_error;
struct dentry *dentry;
struct inode *inode;
struct posix_acl *pacl = NULL, *dpacl = NULL;
unsigned int flags = 0;
/* Get inode */
error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR);
if (error)
return error;
dentry = fhp->fh_dentry;
inode = dentry->d_inode;
if (S_ISDIR(inode->i_mode))
flags = NFS4_ACL_DIR;
host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
if (host_error == -EINVAL) {
return nfserr_attrnotsupp;
} else if (host_error < 0)
goto out_nfserr;
host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
if (host_error < 0)
goto out_release;
if (S_ISDIR(inode->i_mode))
host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
out_release:
posix_acl_release(pacl);
posix_acl_release(dpacl);
out_nfserr:
if (host_error == -EOPNOTSUPP)
return nfserr_attrnotsupp;
else
return nfserrno(host_error);
}
static struct posix_acl *
_get_posix_acl(struct dentry *dentry, char *key)
{
void *buf = NULL;
struct posix_acl *pacl = NULL;
int buflen;
buflen = nfsd_getxattr(dentry, key, &buf);
if (!buflen)
buflen = -ENODATA;
if (buflen <= 0)
return ERR_PTR(buflen);
pacl = posix_acl_from_xattr(buf, buflen);
kfree(buf);
return pacl;
}
int
nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
{
struct inode *inode = dentry->d_inode;
int error = 0;
struct posix_acl *pacl = NULL, *dpacl = NULL;
unsigned int flags = 0;
pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
if (IS_ERR(pacl)) {
error = PTR_ERR(pacl);
pacl = NULL;
goto out;
}
if (S_ISDIR(inode->i_mode)) {
dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
dpacl = NULL;
else if (IS_ERR(dpacl)) {
error = PTR_ERR(dpacl);
dpacl = NULL;
goto out;
}
flags = NFS4_ACL_DIR;
}
*acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
if (IS_ERR(*acl)) {
error = PTR_ERR(*acl);
*acl = NULL;
}
out:
posix_acl_release(pacl);
posix_acl_release(dpacl);
return error;
}
#endif /* defined(CONFIG_NFS_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, MAY_READ },
{ NFS3_ACCESS_EXECUTE, MAY_EXEC },
{ NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_TRUNC },
{ NFS3_ACCESS_EXTEND, MAY_WRITE },
{ 0, 0 }
};
static struct accessmap nfs3_diraccess[] = {
{ NFS3_ACCESS_READ, MAY_READ },
{ NFS3_ACCESS_LOOKUP, MAY_EXEC },
{ NFS3_ACCESS_MODIFY, MAY_EXEC|MAY_WRITE|MAY_TRUNC },
{ NFS3_ACCESS_EXTEND, MAY_EXEC|MAY_WRITE },
{ NFS3_ACCESS_DELETE, 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, MAY_READ },
{ NFS3_ACCESS_EXECUTE, MAY_EXEC },
{ NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_LOCAL_ACCESS },
{ NFS3_ACCESS_EXTEND, MAY_WRITE|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, MAY_NOP);
if (error)
goto out;
export = fhp->fh_export;
dentry = fhp->fh_dentry;
if (S_ISREG(dentry->d_inode->i_mode))
map = nfs3_regaccess;
else if (S_ISDIR(dentry->d_inode->i_mode))
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 */
/*
* Open an existing file or directory.
* The access argument indicates the type of open (read/write/lock)
* N.B. After this call fhp needs an fh_put
*/
__be32
nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
int access, struct file **filp)
{
struct dentry *dentry;
struct inode *inode;
int flags = O_RDONLY|O_LARGEFILE;
__be32 err;
int host_err;
/*
* 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.
*/
err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE);
if (err)
goto out;
dentry = fhp->fh_dentry;
inode = dentry->d_inode;
/* 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) && (access & MAY_WRITE))
goto out;
if (IS_ISMNDLK(inode))
goto out;
if (!inode->i_fop)
goto out;
/*
* Check to see if there are any leases on this file.
* This may block while leases are broken.
*/
host_err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0));
if (host_err == -EWOULDBLOCK)
host_err = -ETIMEDOUT;
if (host_err) /* NOMEM or WOULDBLOCK */
goto out_nfserr;
if (access & MAY_WRITE) {
if (access & MAY_READ)
flags = O_RDWR|O_LARGEFILE;
else
flags = O_WRONLY|O_LARGEFILE;
DQUOT_INIT(inode);
}
*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags);
if (IS_ERR(*filp))
host_err = PTR_ERR(*filp);
out_nfserr:
err = nfserrno(host_err);
out:
return err;
}
/*
* Close a file.
*/
void
nfsd_close(struct file *filp)
{
fput(filp);
}
/*
* Sync a file
* As this calls fsync (not fdatasync) there is no need for a write_inode
* after it.
*/
static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
const struct file_operations *fop)
{
struct inode *inode = dp->d_inode;
int (*fsync) (struct file *, struct dentry *, int);
int err;
err = filemap_fdatawrite(inode->i_mapping);
if (err == 0 && fop && (fsync = fop->fsync))
err = fsync(filp, dp, 0);
if (err == 0)
err = filemap_fdatawait(inode->i_mapping);
return err;
}
static int
nfsd_sync(struct file *filp)
{
int err;
struct inode *inode = filp->f_path.dentry->d_inode;
dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
mutex_lock(&inode->i_mutex);
err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
mutex_unlock(&inode->i_mutex);
return err;
}
int
nfsd_sync_dir(struct dentry *dp)
{
return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
}
/*
* Obtain the readahead parameters for the file
* specified by (dev, ino).
*/
static inline struct raparms *
nfsd_get_raparms(dev_t dev, ino_t 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*11/10;
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);
return ra;
}
/*
* 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_respages + rqstp->rq_resused;
struct page *page = buf->page;
size_t size;
int ret;
ret = buf->ops->confirm(pipe, buf);
if (unlikely(ret))
return ret;
size = sd->len;
if (rqstp->rq_res.page_len == 0) {
get_page(page);
put_page(*pp);
*pp = page;
rqstp->rq_resused++;
rqstp->rq_res.page_base = buf->offset;
rqstp->rq_res.page_len = size;
} else if (page != pp[-1]) {
get_page(page);
if (*pp)
put_page(*pp);
*pp = page;
rqstp->rq_resused++;
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_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
{
struct inode *inode;
struct raparms *ra;
mm_segment_t oldfs;
__be32 err;
int host_err;
err = nfserr_perm;
inode = file->f_path.dentry->d_inode;
#ifdef MSNFS
if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
(!lock_may_read(inode, offset, *count)))
goto out;
#endif
/* Get readahead parameters */
ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
if (ra && ra->p_set)
file->f_ra = ra->p_ra;
if (file->f_op->splice_read && rqstp->rq_splice_ok) {
struct splice_desc sd = {
.len = 0,
.total_len = *count,
.pos = offset,
.u.data = rqstp,
};
rqstp->rq_resused = 1;
host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
} else {
oldfs = get_fs();
set_fs(KERNEL_DS);
host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
set_fs(oldfs);
}
/* Write back readahead params */
if (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);
}
if (host_err >= 0) {
nfsdstats.io_read += host_err;
*count = host_err;
err = 0;
fsnotify_access(file->f_path.dentry);
} else
err = nfserrno(host_err);
out:
return err;
}
static void kill_suid(struct dentry *dentry)
{
struct iattr ia;
ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID;
mutex_lock(&dentry->d_inode->i_mutex);
notify_change(dentry, &ia);
mutex_unlock(&dentry->d_inode->i_mutex);
}
static __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 *stablep)
{
struct svc_export *exp;
struct dentry *dentry;
struct inode *inode;
mm_segment_t oldfs;
__be32 err = 0;
int host_err;
int stable = *stablep;
#ifdef MSNFS
err = nfserr_perm;
if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
(!lock_may_write(file->f_path.dentry->d_inode, offset, cnt)))
goto out;
#endif
dentry = file->f_path.dentry;
inode = dentry->d_inode;
exp = fhp->fh_export;
/*
* Request sync writes if
* - the sync export option has been set, or
* - the client requested O_SYNC behavior (NFSv3 feature).
* - The file system doesn't support fsync().
* When gathered writes have been configured for this volume,
* flushing the data to disk is handled separately below.
*/
if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */
stable = 2;
*stablep = 2; /* FILE_SYNC */
}
if (!EX_ISSYNC(exp))
stable = 0;
if (stable && !EX_WGATHER(exp))
file->f_flags |= O_SYNC;
/* Write the data. */
oldfs = get_fs(); set_fs(KERNEL_DS);
host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
set_fs(oldfs);
if (host_err >= 0) {
nfsdstats.io_write += cnt;
fsnotify_modify(file->f_path.dentry);
}
/* clear setuid/setgid flag after write */
if (host_err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID)))
kill_suid(dentry);
if (host_err >= 0 && stable) {
static ino_t last_ino;
static dev_t last_dev;
/*
* 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:-)
*/
if (EX_WGATHER(exp)) {
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", current->pid);
msleep(10);
dprintk("nfsd: write resume %d\n", current->pid);
}
if (inode->i_state & I_DIRTY) {
dprintk("nfsd: write sync %d\n", current->pid);
host_err=nfsd_sync(file);
}
#if 0
wake_up(&inode->i_wait);
#endif
}
last_ino = inode->i_ino;
last_dev = inode->i_sb->s_dev;
}
dprintk("nfsd: write complete host_err=%d\n", host_err);
if (host_err >= 0)
err = 0;
else
err = nfserrno(host_err);
out:
return err;
}
/*
* 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, struct file *file,
loff_t offset, struct kvec *vec, int vlen,
unsigned long *count)
{
__be32 err;
if (file) {
err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
MAY_READ|MAY_OWNER_OVERRIDE);
if (err)
goto out;
err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
} else {
err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
if (err)
goto out;
err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
nfsd_close(file);
}
out:
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, struct file *file,
loff_t offset, struct kvec *vec, int vlen, unsigned long cnt,
int *stablep)
{
__be32 err = 0;
if (file) {
err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
MAY_WRITE|MAY_OWNER_OVERRIDE);
if (err)
goto out;
err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
stablep);
} else {
err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
if (err)
goto out;
if (cnt)
err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
cnt, stablep);
nfsd_close(file);
}
out:
return err;
}
#ifdef CONFIG_NFSD_V3
/*
* Commit all pending writes to stable storage.
* Strictly speaking, we could sync just the indicated file region here,
* but there's currently no way we can ask the VFS to do so.
*
* 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;
__be32 err;
if ((u64)count > ~(u64)offset)
return nfserr_inval;
if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0)
return err;
if (EX_ISSYNC(fhp->fh_export)) {
if (file->f_op && file->f_op->fsync) {
err = nfserrno(nfsd_sync(file));
} else {
err = nfserr_notsupp;
}
}
nfsd_close(file);
return err;
}
#endif /* CONFIG_NFSD_V3 */
/*
* Create a file (regular, directory, device, fifo); UNIX sockets
* not yet implemented.
* If the response fh has been verified, the parent directory should
* already be locked. 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;
err = nfserr_perm;
if (!flen)
goto out;
err = nfserr_exist;
if (isdotent(fname, flen))
goto out;
err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
if (err)
goto out;
dentry = fhp->fh_dentry;
dirp = dentry->d_inode;
err = nfserr_notdir;
if(!dirp->i_op || !dirp->i_op->lookup)
goto out;
/*
* Check whether the response file handle has been verified yet.
* If it has, the parent directory should already be locked.
*/
if (!resfhp->fh_dentry) {
/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
fh_lock_nested(fhp, I_MUTEX_PARENT);
dchild = lookup_one_len(fname, dentry, flen);
host_err = PTR_ERR(dchild);
if (IS_ERR(dchild))
goto out_nfserr;
err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
if (err)
goto out;
} else {
/* called from nfsd_proc_create */
dchild = dget(resfhp->fh_dentry);
if (!fhp->fh_locked) {
/* not actually possible */
printk(KERN_ERR
"nfsd_create: parent %s/%s not locked!\n",
dentry->d_parent->d_name.name,
dentry->d_name.name);
err = nfserr_io;
goto out;
}
}
/*
* Make sure the child dentry is still negative ...
*/
err = nfserr_exist;
if (dchild->d_inode) {
dprintk("nfsd_create: dentry %s/%s not negative!\n",
dentry->d_name.name, dchild->d_name.name);
goto out;
}
if (!(iap->ia_valid & ATTR_MODE))
iap->ia_mode = 0;
iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
/*
* Get the dir op function pointer.
*/
err = 0;
switch (type) {
case S_IFREG:
host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
break;
case S_IFDIR:
host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
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("nfsd: bad file type %o in nfsd_create\n", type);
host_err = -EINVAL;
}
if (host_err < 0)
goto out_nfserr;
if (EX_ISSYNC(fhp->fh_export)) {
err = nfserrno(nfsd_sync_dir(dentry));
write_inode_now(dchild->d_inode, 1);
}
/* Set file attributes. Mode has already been set and
* setting uid/gid works only for root. Irix appears to
* send along the gid when it tries to implement setgid
* directories via NFS.
*/
if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
__be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
if (err2)
err = err2;
}
/*
* Update the file handle to get the new inode info.
*/
if (!err)
err = fh_update(resfhp);
out:
if (dchild && !IS_ERR(dchild))
dput(dchild);
return err;
out_nfserr:
err = nfserrno(host_err);
goto out;
}
#ifdef CONFIG_NFSD_V3
/*
* NFSv3 version of nfsd_create
*/
__be32
nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
char *fname, int flen, struct iattr *iap,
struct svc_fh *resfhp, int createmode, u32 *verifier,
int *truncp, int *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, MAY_CREATE);
if (err)
goto out;
dentry = fhp->fh_dentry;
dirp = dentry->d_inode;
/* Get all the sanity checks out of the way before
* we lock the parent. */
err = nfserr_notdir;
if(!dirp->i_op || !dirp->i_op->lookup)
goto out;
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;
err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
if (err)
goto out;
if (createmode == NFS3_CREATE_EXCLUSIVE) {
/* 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 (dchild->d_inode) {
err = 0;
switch (createmode) {
case NFS3_CREATE_UNCHECKED:
if (! S_ISREG(dchild->d_inode->i_mode))
err = nfserr_exist;
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 ( dchild->d_inode->i_mtime.tv_sec == v_mtime
&& dchild->d_inode->i_atime.tv_sec == v_atime
&& dchild->d_inode->i_size == 0 )
break;
/* fallthru */
case NFS3_CREATE_GUARDED:
err = nfserr_exist;
}
goto out;
}
host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
if (host_err < 0)
goto out_nfserr;
if (created)
*created = 1;
if (EX_ISSYNC(fhp->fh_export)) {
err = nfserrno(nfsd_sync_dir(dentry));
/* setattr will sync the child (or not) */
}
if (createmode == NFS3_CREATE_EXCLUSIVE) {
/* 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 file attributes.
* Irix appears to send along the gid when it tries to
* implement setgid directories via NFS. Clear out all that cruft.
*/
set_attr:
if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) {
__be32 err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
if (err2)
err = err2;
}
/*
* 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);
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)
{
struct dentry *dentry;
struct inode *inode;
mm_segment_t oldfs;
__be32 err;
int host_err;
err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP);
if (err)
goto out;
dentry = fhp->fh_dentry;
inode = dentry->d_inode;
err = nfserr_inval;
if (!inode->i_op || !inode->i_op->readlink)
goto out;
touch_atime(fhp->fh_export->ex_mnt, dentry);
/* N.B. Why does this call need a get_fs()??
* Remove the set_fs and watch the fireworks:-) --okir
*/
oldfs = get_fs(); set_fs(KERNEL_DS);
host_err = inode->i_op->readlink(dentry, buf, *lenp);
set_fs(oldfs);
if (host_err < 0)
goto out_nfserr;
*lenp = host_err;
err = 0;
out:
return err;
out_nfserr:
err = nfserrno(host_err);
goto out;
}
/*
* 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, int plen,
struct svc_fh *resfhp,
struct iattr *iap)
{
struct dentry *dentry, *dnew;
__be32 err, cerr;
int host_err;
umode_t mode;
err = nfserr_noent;
if (!flen || !plen)
goto out;
err = nfserr_exist;
if (isdotent(fname, flen))
goto out;
err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
if (err)
goto out;
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;
mode = S_IALLUGO;
/* Only the MODE ATTRibute is even vaguely meaningful */
if (iap && (iap->ia_valid & ATTR_MODE))
mode = iap->ia_mode & S_IALLUGO;
if (unlikely(path[plen] != 0)) {
char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
if (path_alloced == NULL)
host_err = -ENOMEM;
else {
strncpy(path_alloced, path, plen);
path_alloced[plen] = 0;
host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
kfree(path_alloced);
}
} else
host_err = vfs_symlink(dentry->d_inode, dnew, path, mode);
if (!host_err) {
if (EX_ISSYNC(fhp->fh_export))
host_err = nfsd_sync_dir(dentry);
}
err = nfserrno(host_err);
fh_unlock(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, *dest;
__be32 err;
int host_err;
err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE);
if (err)
goto out;
err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP);
if (err)
goto out;
err = nfserr_perm;
if (!len)
goto out;
err = nfserr_exist;
if (isdotent(name, len))
goto out;
fh_lock_nested(ffhp, I_MUTEX_PARENT);
ddir = ffhp->fh_dentry;
dirp = ddir->d_inode;
dnew = lookup_one_len(name, ddir, len);
host_err = PTR_ERR(dnew);
if (IS_ERR(dnew))
goto out_nfserr;
dold = tfhp->fh_dentry;
dest = dold->d_inode;
host_err = vfs_link(dold, dirp, dnew);
if (!host_err) {
if (EX_ISSYNC(ffhp->fh_export)) {
err = nfserrno(nfsd_sync_dir(ddir));
write_inode_now(dest, 1);
}
err = 0;
} else {
if (host_err == -EXDEV && rqstp->rq_vers == 2)
err = nfserr_acces;
else
err = nfserrno(host_err);
}
dput(dnew);
out_unlock:
fh_unlock(ffhp);
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, MAY_REMOVE);
if (err)
goto out;
err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE);
if (err)
goto out;
fdentry = ffhp->fh_dentry;
fdir = fdentry->d_inode;
tdentry = tfhp->fh_dentry;
tdir = tdentry->d_inode;
err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
if (ffhp->fh_export != tfhp->fh_export)
goto out;
err = nfserr_perm;
if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
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 = 1;
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 (!odentry->d_inode)
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;
#ifdef MSNFS
if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
((atomic_read(&odentry->d_count) > 1)
|| (atomic_read(&ndentry->d_count) > 1))) {
host_err = -EPERM;
} else
#endif
host_err = vfs_rename(fdir, odentry, tdir, ndentry);
if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
host_err = nfsd_sync_dir(tdentry);
if (!host_err)
host_err = nfsd_sync_dir(fdentry);
}
out_dput_new:
dput(ndentry);
out_dput_old:
dput(odentry);
out_nfserr:
err = nfserrno(host_err);
/* we cannot reply 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 = 0;
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, MAY_REMOVE);
if (err)
goto out;
fh_lock_nested(fhp, I_MUTEX_PARENT);
dentry = fhp->fh_dentry;
dirp = dentry->d_inode;
rdentry = lookup_one_len(fname, dentry, flen);
host_err = PTR_ERR(rdentry);
if (IS_ERR(rdentry))
goto out_nfserr;
if (!rdentry->d_inode) {
dput(rdentry);
err = nfserr_noent;
goto out;
}
if (!type)
type = rdentry->d_inode->i_mode & S_IFMT;
if (type != S_IFDIR) { /* It's UNLINK */
#ifdef MSNFS
if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
(atomic_read(&rdentry->d_count) > 1)) {
host_err = -EPERM;
} else
#endif
host_err = vfs_unlink(dirp, rdentry);
} else { /* It's RMDIR */
host_err = vfs_rmdir(dirp, rdentry);
}
dput(rdentry);
if (host_err)
goto out_nfserr;
if (EX_ISSYNC(fhp->fh_export))
host_err = nfsd_sync_dir(dentry);
out_nfserr:
err = nfserrno(host_err);
out:
return 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, filldir_t func)
{
__be32 err;
int host_err;
struct file *file;
loff_t offset = *offsetp;
err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file);
if (err)
goto out;
offset = vfs_llseek(file, offset, 0);
if (offset < 0) {
err = nfserrno((int)offset);
goto out_close;
}
/*
* Read the directory entries. This silly loop is necessary because
* readdir() is not guaranteed to fill up the entire buffer, but
* may choose to do less.
*/
do {
cdp->err = nfserr_eof; /* will be cleared on successful read */
host_err = vfs_readdir(file, func, cdp);
} while (host_err >=0 && cdp->err == nfs_ok);
if (host_err)
err = nfserrno(host_err);
else
err = cdp->err;
*offsetp = vfs_llseek(file, 0, 1);
if (err == nfserr_eof || err == nfserr_toosmall)
err = nfs_ok; /* can still be found in ->err */
out_close:
nfsd_close(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)
{
__be32 err = fh_verify(rqstp, fhp, 0, MAY_NOP);
if (!err && vfs_statfs(fhp->fh_dentry,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 = dentry->d_inode;
int err;
if (acc == 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 & MAY_READ)? " read" : "",
(acc & MAY_WRITE)? " write" : "",
(acc & MAY_EXEC)? " exec" : "",
(acc & MAY_SATTR)? " sattr" : "",
(acc & MAY_TRUNC)? " trunc" : "",
(acc & MAY_LOCK)? " lock" : "",
(acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "",
inode->i_mode,
IS_IMMUTABLE(inode)? " immut" : "",
IS_APPEND(inode)? " append" : "",
IS_RDONLY(inode)? " 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 & MAY_LOCAL_ACCESS))
if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
if (exp_rdonly(rqstp, exp) || IS_RDONLY(inode))
return nfserr_rofs;
if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
return nfserr_perm;
}
if ((acc & MAY_TRUNC) && IS_APPEND(inode))
return nfserr_perm;
if (acc & 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 = MAY_READ | 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 & MAY_OWNER_OVERRIDE) &&
inode->i_uid == current->fsuid)
return 0;
err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL);
/* Allow read access to binaries even when mode 111 */
if (err == -EACCES && S_ISREG(inode->i_mode) &&
acc == (MAY_READ | MAY_OWNER_OVERRIDE))
err = permission(inode, MAY_EXEC, NULL);
return err? nfserrno(err) : 0;
}
void
nfsd_racache_shutdown(void)
{
if (!raparml)
return;
dprintk("nfsd: freeing readahead buffers.\n");
kfree(raparml);
raparml = NULL;
}
/*
* Initialize readahead param cache
*/
int
nfsd_racache_init(int cache_size)
{
int i;
int j = 0;
int nperbucket;
if (raparml)
return 0;
if (cache_size < 2*RAPARM_HASH_SIZE)
cache_size = 2*RAPARM_HASH_SIZE;
raparml = kcalloc(cache_size, sizeof(struct raparms), GFP_KERNEL);
if (!raparml) {
printk(KERN_WARNING
"nfsd: Could not allocate memory read-ahead cache.\n");
return -ENOMEM;
}
dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
for (i = 0 ; i < RAPARM_HASH_SIZE ; i++) {
raparm_hash[i].pb_head = NULL;
spin_lock_init(&raparm_hash[i].pb_lock);
}
nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
for (i = 0; i < cache_size - 1; i++) {
if (i % nperbucket == 0)
raparm_hash[j++].pb_head = raparml + i;
if (i % nperbucket < nperbucket-1)
raparml[i].p_next = raparml + i + 1;
}
nfsdstats.ra_size = cache_size;
return 0;
}
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
struct posix_acl *
nfsd_get_posix_acl(struct svc_fh *fhp, int type)
{
struct inode *inode = fhp->fh_dentry->d_inode;
char *name;
void *value = NULL;
ssize_t size;
struct posix_acl *acl;
if (!IS_POSIXACL(inode))
return ERR_PTR(-EOPNOTSUPP);
switch (type) {
case ACL_TYPE_ACCESS:
name = POSIX_ACL_XATTR_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = POSIX_ACL_XATTR_DEFAULT;
break;
default:
return ERR_PTR(-EOPNOTSUPP);
}
size = nfsd_getxattr(fhp->fh_dentry, name, &value);
if (size < 0)
return ERR_PTR(size);
acl = posix_acl_from_xattr(value, size);
kfree(value);
return acl;
}
int
nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
{
struct inode *inode = fhp->fh_dentry->d_inode;
char *name;
void *value = NULL;
size_t size;
int error;
if (!IS_POSIXACL(inode) || !inode->i_op ||
!inode->i_op->setxattr || !inode->i_op->removexattr)
return -EOPNOTSUPP;
switch(type) {
case ACL_TYPE_ACCESS:
name = POSIX_ACL_XATTR_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = POSIX_ACL_XATTR_DEFAULT;
break;
default:
return -EOPNOTSUPP;
}
if (acl && acl->a_count) {
size = posix_acl_xattr_size(acl->a_count);
value = kmalloc(size, GFP_KERNEL);
if (!value)
return -ENOMEM;
error = posix_acl_to_xattr(acl, value, size);
if (error < 0)
goto getout;
size = error;
} else
size = 0;
if (size)
error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
else {
if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
error = 0;
else {
error = vfs_removexattr(fhp->fh_dentry, name);
if (error == -ENODATA)
error = 0;
}
}
getout:
kfree(value);
return error;
}
#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */