/*
* linux/fs/nfs/file.c
*
* Copyright (C) 1992 Rick Sladkey
*/
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/falloc.h>
#include <linux/nfs_fs.h>
#include <uapi/linux/btrfs.h> /* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */
#include "delegation.h"
#include "internal.h"
#include "iostat.h"
#include "fscache.h"
#include "pnfs.h"
#include "nfstrace.h"
#ifdef CONFIG_NFS_V4_2
#include "nfs42.h"
#endif
#define NFSDBG_FACILITY NFSDBG_FILE
static int
nfs4_file_open(struct inode *inode, struct file *filp)
{
struct nfs_open_context *ctx;
struct dentry *dentry = file_dentry(filp);
struct dentry *parent = NULL;
struct inode *dir;
unsigned openflags = filp->f_flags;
struct iattr attr;
int err;
/*
* If no cached dentry exists or if it's negative, NFSv4 handled the
* opens in ->lookup() or ->create().
*
* We only get this far for a cached positive dentry. We skipped
* revalidation, so handle it here by dropping the dentry and returning
* -EOPENSTALE. The VFS will retry the lookup/create/open.
*/
dprintk("NFS: open file(%pd2)\n", dentry);
err = nfs_check_flags(openflags);
if (err)
return err;
if ((openflags & O_ACCMODE) == 3)
openflags--;
/* We can't create new files here */
openflags &= ~(O_CREAT|O_EXCL);
parent = dget_parent(dentry);
dir = d_inode(parent);
ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode);
err = PTR_ERR(ctx);
if (IS_ERR(ctx))
goto out;
attr.ia_valid = ATTR_OPEN;
if (openflags & O_TRUNC) {
attr.ia_valid |= ATTR_SIZE;
attr.ia_size = 0;
nfs_sync_inode(inode);
}
inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
switch (err) {
case -EPERM:
case -EACCES:
case -EDQUOT:
case -ENOSPC:
case -EROFS:
goto out_put_ctx;
default:
goto out_drop;
}
}
if (inode != d_inode(dentry))
goto out_drop;
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
nfs_file_set_open_context(filp, ctx);
nfs_fscache_open_file(inode, filp);
err = 0;
out_put_ctx:
put_nfs_open_context(ctx);
out:
dput(parent);
return err;
out_drop:
d_drop(dentry);
err = -EOPENSTALE;
goto out_put_ctx;
}
/*
* Flush all dirty pages, and check for write errors.
*/
static int
nfs4_file_flush(struct file *file, fl_owner_t id)
{
struct inode *inode = file_inode(file);
dprintk("NFS: flush(%pD2)\n", file);
nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
if ((file->f_mode & FMODE_WRITE) == 0)
return 0;
/*
* If we're holding a write delegation, then check if we're required
* to flush the i/o on close. If not, then just start the i/o now.
*/
if (!nfs4_delegation_flush_on_close(inode))
return filemap_fdatawrite(file->f_mapping);
/* Flush writes to the server and return any errors */
return vfs_fsync(file, 0);
}
static int
nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
int ret;
struct inode *inode = file_inode(file);
trace_nfs_fsync_enter(inode);
nfs_inode_dio_wait(inode);
do {
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (ret != 0)
break;
mutex_lock(&inode->i_mutex);
ret = nfs_file_fsync_commit(file, start, end, datasync);
if (!ret)
ret = pnfs_sync_inode(inode, !!datasync);
mutex_unlock(&inode->i_mutex);
/*
* If nfs_file_fsync_commit detected a server reboot, then
* resend all dirty pages that might have been covered by
* the NFS_CONTEXT_RESEND_WRITES flag
*/
start = 0;
end = LLONG_MAX;
} while (ret == -EAGAIN);
trace_nfs_fsync_exit(inode, ret);
return ret;
}
#ifdef CONFIG_NFS_V4_2
static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
{
loff_t ret;
switch (whence) {
case SEEK_HOLE:
case SEEK_DATA:
ret = nfs42_proc_llseek(filep, offset, whence);
if (ret != -ENOTSUPP)
return ret;
default:
return nfs_file_llseek(filep, offset, whence);
}
}
static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
{
struct inode *inode = file_inode(filep);
long ret;
if (!S_ISREG(inode->i_mode))
return -EOPNOTSUPP;
if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
return -EOPNOTSUPP;
ret = inode_newsize_ok(inode, offset + len);
if (ret < 0)
return ret;
if (mode & FALLOC_FL_PUNCH_HOLE)
return nfs42_proc_deallocate(filep, offset, len);
return nfs42_proc_allocate(filep, offset, len);
}
static noinline long
nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
u64 src_off, u64 dst_off, u64 count)
{
struct inode *dst_inode = file_inode(dst_file);
struct nfs_server *server = NFS_SERVER(dst_inode);
struct fd src_file;
struct inode *src_inode;
unsigned int bs = server->clone_blksize;
bool same_inode = false;
int ret;
/* dst file must be opened for writing */
if (!(dst_file->f_mode & FMODE_WRITE))
return -EINVAL;
ret = mnt_want_write_file(dst_file);
if (ret)
return ret;
src_file = fdget(srcfd);
if (!src_file.file) {
ret = -EBADF;
goto out_drop_write;
}
src_inode = file_inode(src_file.file);
if (src_inode == dst_inode)
same_inode = true;
/* src file must be opened for reading */
if (!(src_file.file->f_mode & FMODE_READ))
goto out_fput;
/* src and dst must be regular files */
ret = -EISDIR;
if (!S_ISREG(src_inode->i_mode) || !S_ISREG(dst_inode->i_mode))
goto out_fput;
ret = -EXDEV;
if (src_file.file->f_path.mnt != dst_file->f_path.mnt ||
src_inode->i_sb != dst_inode->i_sb)
goto out_fput;
/* check alignment w.r.t. clone_blksize */
ret = -EINVAL;
if (bs) {
if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
goto out_fput;
if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
goto out_fput;
}
/* verify if ranges are overlapped within the same file */
if (same_inode) {
if (dst_off + count > src_off && dst_off < src_off + count)
goto out_fput;
}
/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
if (same_inode) {
mutex_lock(&src_inode->i_mutex);
} else if (dst_inode < src_inode) {
mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT);
mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
} else {
mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_CHILD);
}
/* flush all pending writes on both src and dst so that server
* has the latest data */
ret = nfs_sync_inode(src_inode);
if (ret)
goto out_unlock;
ret = nfs_sync_inode(dst_inode);
if (ret)
goto out_unlock;
ret = nfs42_proc_clone(src_file.file, dst_file, src_off, dst_off, count);
/* truncate inode page cache of the dst range so that future reads can fetch
* new data from server */
if (!ret)
truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
out_unlock:
if (same_inode) {
mutex_unlock(&src_inode->i_mutex);
} else if (dst_inode < src_inode) {
mutex_unlock(&src_inode->i_mutex);
mutex_unlock(&dst_inode->i_mutex);
} else {
mutex_unlock(&dst_inode->i_mutex);
mutex_unlock(&src_inode->i_mutex);
}
out_fput:
fdput(src_file);
out_drop_write:
mnt_drop_write_file(dst_file);
return ret;
}
static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp)
{
struct btrfs_ioctl_clone_range_args args;
if (copy_from_user(&args, argp, sizeof(args)))
return -EFAULT;
return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_offset,
args.dest_offset, args.src_length);
}
long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
switch (cmd) {
case BTRFS_IOC_CLONE:
return nfs42_ioctl_clone(file, arg, 0, 0, 0);
case BTRFS_IOC_CLONE_RANGE:
return nfs42_ioctl_clone_range(file, argp);
}
return -ENOTTY;
}
#endif /* CONFIG_NFS_V4_2 */
const struct file_operations nfs4_file_operations = {
.read_iter = nfs_file_read,
.write_iter = nfs_file_write,
.mmap = nfs_file_mmap,
.open = nfs4_file_open,
.flush = nfs4_file_flush,
.release = nfs_file_release,
.fsync = nfs4_file_fsync,
.lock = nfs_lock,
.flock = nfs_flock,
.splice_read = nfs_file_splice_read,
.splice_write = iter_file_splice_write,
.check_flags = nfs_check_flags,
.setlease = simple_nosetlease,
#ifdef CONFIG_NFS_V4_2
.llseek = nfs4_file_llseek,
.fallocate = nfs42_fallocate,
.unlocked_ioctl = nfs4_ioctl,
.compat_ioctl = nfs4_ioctl,
#else
.llseek = nfs_file_llseek,
#endif
};
