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