/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
#include <sys/zfs_context.h>
#include <sys/zfs_file.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <linux/falloc.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#ifdef HAVE_FDTABLE_HEADER
#include <linux/fdtable.h>
#endif
/*
* Open file
*
* path - fully qualified path to file
* flags - file attributes O_READ / O_WRITE / O_EXCL
* fpp - pointer to return file pointer
*
* Returns 0 on success underlying error on failure.
*/
int
zfs_file_open(const char *path, int flags, int mode, zfs_file_t **fpp)
{
struct file *filp;
int saved_umask;
if (!(flags & O_CREAT) && (flags & O_WRONLY))
flags |= O_EXCL;
if (flags & O_CREAT)
saved_umask = xchg(¤t->fs->umask, 0);
filp = filp_open(path, flags, mode);
if (flags & O_CREAT)
(void) xchg(¤t->fs->umask, saved_umask);
if (IS_ERR(filp))
return (-PTR_ERR(filp));
*fpp = filp;
return (0);
}
void
zfs_file_close(zfs_file_t *fp)
{
filp_close(fp, 0);
}
static ssize_t
zfs_file_write_impl(zfs_file_t *fp, const void *buf, size_t count, loff_t *off)
{
#if defined(HAVE_KERNEL_WRITE_PPOS)
return (kernel_write(fp, buf, count, off));
#else
mm_segment_t saved_fs;
ssize_t rc;
saved_fs = get_fs();
set_fs(KERNEL_DS);
rc = vfs_write(fp, (__force const char __user __user *)buf, count, off);
set_fs(saved_fs);
return (rc);
#endif
}
/*
* Stateful write - use os internal file pointer to determine where to
* write and update on successful completion.
*
* fp - pointer to file (pipe, socket, etc) to write to
* buf - buffer to write
* count - # of bytes to write
* resid - pointer to count of unwritten bytes (if short write)
*
* Returns 0 on success errno on failure.
*/
int
zfs_file_write(zfs_file_t *fp, const void *buf, size_t count, ssize_t *resid)
{
loff_t off = fp->f_pos;
ssize_t rc;
rc = zfs_file_write_impl(fp, buf, count, &off);
if (rc < 0)
return (-rc);
fp->f_pos = off;
if (resid) {
*resid = count - rc;
} else if (rc != count) {
return (EIO);
}
return (0);
}
/*
* Stateless write - os internal file pointer is not updated.
*
* fp - pointer to file (pipe, socket, etc) to write to
* buf - buffer to write
* count - # of bytes to write
* off - file offset to write to (only valid for seekable types)
* resid - pointer to count of unwritten bytes
*
* Returns 0 on success errno on failure.
*/
int
zfs_file_pwrite(zfs_file_t *fp, const void *buf, size_t count, loff_t off,
ssize_t *resid)
{
ssize_t rc;
rc = zfs_file_write_impl(fp, buf, count, &off);
if (rc < 0)
return (-rc);
if (resid) {
*resid = count - rc;
} else if (rc != count) {
return (EIO);
}
return (0);
}
static ssize_t
zfs_file_read_impl(zfs_file_t *fp, void *buf, size_t count, loff_t *off)
{
#if defined(HAVE_KERNEL_READ_PPOS)
return (kernel_read(fp, buf, count, off));
#else
mm_segment_t saved_fs;
ssize_t rc;
saved_fs = get_fs();
set_fs(KERNEL_DS);
rc = vfs_read(fp, (void __user *)buf, count, off);
set_fs(saved_fs);
return (rc);
#endif
}
/*
* Stateful read - use os internal file pointer to determine where to
* read and update on successful completion.
*
* fp - pointer to file (pipe, socket, etc) to read from
* buf - buffer to write
* count - # of bytes to read
* resid - pointer to count of unread bytes (if short read)
*
* Returns 0 on success errno on failure.
*/
int
zfs_file_read(zfs_file_t *fp, void *buf, size_t count, ssize_t *resid)
{
loff_t off = fp->f_pos;
ssize_t rc;
rc = zfs_file_read_impl(fp, buf, count, &off);
if (rc < 0)
return (-rc);
fp->f_pos = off;
if (resid) {
*resid = count - rc;
} else if (rc != count) {
return (EIO);
}
return (0);
}
/*
* Stateless read - os internal file pointer is not updated.
*
* fp - pointer to file (pipe, socket, etc) to read from
* buf - buffer to write
* count - # of bytes to write
* off - file offset to read from (only valid for seekable types)
* resid - pointer to count of unwritten bytes (if short write)
*
* Returns 0 on success errno on failure.
*/
int
zfs_file_pread(zfs_file_t *fp, void *buf, size_t count, loff_t off,
ssize_t *resid)
{
ssize_t rc;
rc = zfs_file_read_impl(fp, buf, count, &off);
if (rc < 0)
return (-rc);
if (resid) {
*resid = count - rc;
} else if (rc != count) {
return (EIO);
}
return (0);
}
/*
* lseek - set / get file pointer
*
* fp - pointer to file (pipe, socket, etc) to read from
* offp - value to seek to, returns current value plus passed offset
* whence - see man pages for standard lseek whence values
*
* Returns 0 on success errno on failure (ESPIPE for non seekable types)
*/
int
zfs_file_seek(zfs_file_t *fp, loff_t *offp, int whence)
{
loff_t rc;
if (*offp < 0)
return (EINVAL);
rc = vfs_llseek(fp, *offp, whence);
if (rc < 0)
return (-rc);
*offp = rc;
return (0);
}
/*
* Get file attributes
*
* filp - file pointer
* zfattr - pointer to file attr structure
*
* Currently only used for fetching size and file mode.
*
* Returns 0 on success or error code of underlying getattr call on failure.
*/
int
zfs_file_getattr(zfs_file_t *filp, zfs_file_attr_t *zfattr)
{
struct kstat stat;
int rc;
#if defined(HAVE_4ARGS_VFS_GETATTR)
rc = vfs_getattr(&filp->f_path, &stat, STATX_BASIC_STATS,
AT_STATX_SYNC_AS_STAT);
#elif defined(HAVE_2ARGS_VFS_GETATTR)
rc = vfs_getattr(&filp->f_path, &stat);
#elif defined(HAVE_3ARGS_VFS_GETATTR)
rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, &stat);
#else
#error "No available vfs_getattr()"
#endif
if (rc)
return (-rc);
zfattr->zfa_size = stat.size;
zfattr->zfa_mode = stat.mode;
return (0);
}
/*
* Sync file to disk
*
* filp - file pointer
* flags - O_SYNC and or O_DSYNC
*
* Returns 0 on success or error code of underlying sync call on failure.
*/
int
zfs_file_fsync(zfs_file_t *filp, int flags)
{
int datasync = 0;
int error;
int fstrans;
if (flags & O_DSYNC)
datasync = 1;
/*
* May enter XFS which generates a warning when PF_FSTRANS is set.
* To avoid this the flag is cleared over vfs_sync() and then reset.
*/
fstrans = __spl_pf_fstrans_check();
if (fstrans)
current->flags &= ~(__SPL_PF_FSTRANS);
error = -vfs_fsync(filp, datasync);
if (fstrans)
current->flags |= __SPL_PF_FSTRANS;
return (error);
}
/*
* fallocate - allocate or free space on disk
*
* fp - file pointer
* mode (non-standard options for hole punching etc)
* offset - offset to start allocating or freeing from
* len - length to free / allocate
*
* OPTIONAL
*/
int
zfs_file_fallocate(zfs_file_t *fp, int mode, loff_t offset, loff_t len)
{
/*
* May enter XFS which generates a warning when PF_FSTRANS is set.
* To avoid this the flag is cleared over vfs_sync() and then reset.
*/
int fstrans = __spl_pf_fstrans_check();
if (fstrans)
current->flags &= ~(__SPL_PF_FSTRANS);
/*
* When supported by the underlying file system preferentially
* use the fallocate() callback to preallocate the space.
*/
int error = EOPNOTSUPP;
if (fp->f_op->fallocate)
error = fp->f_op->fallocate(fp, mode, offset, len);
if (fstrans)
current->flags |= __SPL_PF_FSTRANS;
return (error);
}
/*
* Request current file pointer offset
*
* fp - pointer to file
*
* Returns current file offset.
*/
loff_t
zfs_file_off(zfs_file_t *fp)
{
return (fp->f_pos);
}
/*
* Request file pointer private data
*
* fp - pointer to file
*
* Returns pointer to file private data.
*/
void *
zfs_file_private(zfs_file_t *fp)
{
return (fp->private_data);
}
/*
* unlink file
*
* path - fully qualified file path
*
* Returns 0 on success.
*
* OPTIONAL
*/
int
zfs_file_unlink(const char *path)
{
return (EOPNOTSUPP);
}
/*
* Get reference to file pointer
*
* fd - input file descriptor
*
* Returns pointer to file struct or NULL
*/
zfs_file_t *
zfs_file_get(int fd)
{
return (fget(fd));
}
/*
* Drop reference to file pointer
*
* fp - input file struct pointer
*/
void
zfs_file_put(zfs_file_t *fp)
{
fput(fp);
}
