Retire .write/.read file operations

The .write/.read file operations callbacks can be retired since
support for .read_iter/.write_iter and .aio_read/.aio_write has
been added.  The vfs_write()/vfs_read() entry functions will
select the correct interface for the kernel.  This is desirable
because all VFS write/read operations now rely on common code.

This change also add the generic write checks to make sure that
ulimits are enforced correctly on write.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #5587 
Closes #5673
This commit is contained in:
Chunwei Chen 2017-01-27 10:43:39 -08:00 committed by Brian Behlendorf
parent 986dd8aacc
commit 933ec99951
6 changed files with 132 additions and 37 deletions

View File

@ -25,3 +25,24 @@ AC_DEFUN([ZFS_AC_KERNEL_VFS_RW_ITERATE],
AC_MSG_RESULT(no) AC_MSG_RESULT(no)
]) ])
]) ])
dnl #
dnl # Linux 4.1.x API
dnl #
AC_DEFUN([ZFS_AC_KERNEL_GENERIC_WRITE_CHECKS],
[AC_MSG_CHECKING([whether generic_write_checks() takes kiocb])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
],[
struct kiocb *iocb = NULL;
struct iov_iter *iov = NULL;
generic_write_checks(iocb, iov);
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_GENERIC_WRITE_CHECKS_KIOCB, 1,
[generic_write_checks() takes kiocb])
],[
AC_MSG_RESULT(no)
])
])

View File

@ -104,6 +104,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL_LSEEK_EXECUTE ZFS_AC_KERNEL_LSEEK_EXECUTE
ZFS_AC_KERNEL_VFS_ITERATE ZFS_AC_KERNEL_VFS_ITERATE
ZFS_AC_KERNEL_VFS_RW_ITERATE ZFS_AC_KERNEL_VFS_RW_ITERATE
ZFS_AC_KERNEL_GENERIC_WRITE_CHECKS
ZFS_AC_KERNEL_KMAP_ATOMIC_ARGS ZFS_AC_KERNEL_KMAP_ATOMIC_ARGS
ZFS_AC_KERNEL_FOLLOW_DOWN_ONE ZFS_AC_KERNEL_FOLLOW_DOWN_ONE
ZFS_AC_KERNEL_MAKE_REQUEST_FN ZFS_AC_KERNEL_MAKE_REQUEST_FN

View File

@ -258,21 +258,6 @@ zpl_read_common(struct inode *ip, const char *buf, size_t len, loff_t *ppos,
flags, cr, 0)); flags, cr, 0));
} }
static ssize_t
zpl_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
{
cred_t *cr = CRED();
ssize_t read;
crhold(cr);
read = zpl_read_common(filp->f_mapping->host, buf, len, ppos,
UIO_USERSPACE, filp->f_flags, cr);
crfree(cr);
file_accessed(filp);
return (read);
}
static ssize_t static ssize_t
zpl_iter_read_common(struct kiocb *kiocb, const struct iovec *iovp, zpl_iter_read_common(struct kiocb *kiocb, const struct iovec *iovp,
unsigned long nr_segs, size_t count, uio_seg_t seg, size_t skip) unsigned long nr_segs, size_t count, uio_seg_t seg, size_t skip)
@ -311,7 +296,14 @@ static ssize_t
zpl_aio_read(struct kiocb *kiocb, const struct iovec *iovp, zpl_aio_read(struct kiocb *kiocb, const struct iovec *iovp,
unsigned long nr_segs, loff_t pos) unsigned long nr_segs, loff_t pos)
{ {
return (zpl_iter_read_common(kiocb, iovp, nr_segs, kiocb->ki_nbytes, ssize_t ret;
size_t count;
ret = generic_segment_checks(iovp, &nr_segs, &count, VERIFY_WRITE);
if (ret)
return (ret);
return (zpl_iter_read_common(kiocb, iovp, nr_segs, count,
UIO_USERSPACE, 0)); UIO_USERSPACE, 0));
} }
#endif /* HAVE_VFS_RW_ITERATE */ #endif /* HAVE_VFS_RW_ITERATE */
@ -349,6 +341,7 @@ zpl_write_common_iovec(struct inode *ip, const struct iovec *iovp, size_t count,
return (wrote); return (wrote);
} }
inline ssize_t inline ssize_t
zpl_write_common(struct inode *ip, const char *buf, size_t len, loff_t *ppos, zpl_write_common(struct inode *ip, const char *buf, size_t len, loff_t *ppos,
uio_seg_t segment, int flags, cred_t *cr) uio_seg_t segment, int flags, cred_t *cr)
@ -362,20 +355,6 @@ zpl_write_common(struct inode *ip, const char *buf, size_t len, loff_t *ppos,
flags, cr, 0)); flags, cr, 0));
} }
static ssize_t
zpl_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
cred_t *cr = CRED();
ssize_t wrote;
crhold(cr);
wrote = zpl_write_common(filp->f_mapping->host, buf, len, ppos,
UIO_USERSPACE, filp->f_flags, cr);
crfree(cr);
return (wrote);
}
static ssize_t static ssize_t
zpl_iter_write_common(struct kiocb *kiocb, const struct iovec *iovp, zpl_iter_write_common(struct kiocb *kiocb, const struct iovec *iovp,
unsigned long nr_segs, size_t count, uio_seg_t seg, size_t skip) unsigned long nr_segs, size_t count, uio_seg_t seg, size_t skip)
@ -396,16 +375,40 @@ zpl_iter_write_common(struct kiocb *kiocb, const struct iovec *iovp,
static ssize_t static ssize_t
zpl_iter_write(struct kiocb *kiocb, struct iov_iter *from) zpl_iter_write(struct kiocb *kiocb, struct iov_iter *from)
{ {
size_t count;
ssize_t ret; ssize_t ret;
uio_seg_t seg = UIO_USERSPACE; uio_seg_t seg = UIO_USERSPACE;
#ifndef HAVE_GENERIC_WRITE_CHECKS_KIOCB
struct file *file = kiocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *ip = mapping->host;
int isblk = S_ISBLK(ip->i_mode);
count = iov_iter_count(from);
ret = generic_write_checks(file, &kiocb->ki_pos, &count, isblk);
#else
/*
* XXX - ideally this check should be in the same lock region with
* write operations, so that there's no TOCTTOU race when doing
* append and someone else grow the file.
*/
ret = generic_write_checks(kiocb, from);
count = ret;
#endif
if (ret <= 0)
return (ret);
if (from->type & ITER_KVEC) if (from->type & ITER_KVEC)
seg = UIO_SYSSPACE; seg = UIO_SYSSPACE;
if (from->type & ITER_BVEC) if (from->type & ITER_BVEC)
seg = UIO_BVEC; seg = UIO_BVEC;
ret = zpl_iter_write_common(kiocb, from->iov, from->nr_segs, ret = zpl_iter_write_common(kiocb, from->iov, from->nr_segs,
iov_iter_count(from), seg, from->iov_offset); count, seg, from->iov_offset);
if (ret > 0) if (ret > 0)
iov_iter_advance(from, ret); iov_iter_advance(from, ret);
return (ret); return (ret);
} }
#else #else
@ -413,7 +416,22 @@ static ssize_t
zpl_aio_write(struct kiocb *kiocb, const struct iovec *iovp, zpl_aio_write(struct kiocb *kiocb, const struct iovec *iovp,
unsigned long nr_segs, loff_t pos) unsigned long nr_segs, loff_t pos)
{ {
return (zpl_iter_write_common(kiocb, iovp, nr_segs, kiocb->ki_nbytes, struct file *file = kiocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *ip = mapping->host;
int isblk = S_ISBLK(ip->i_mode);
size_t count;
ssize_t ret;
ret = generic_segment_checks(iovp, &nr_segs, &count, VERIFY_READ);
if (ret)
return (ret);
ret = generic_write_checks(file, &pos, &count, isblk);
if (ret)
return (ret);
return (zpl_iter_write_common(kiocb, iovp, nr_segs, count,
UIO_USERSPACE, 0)); UIO_USERSPACE, 0));
} }
#endif /* HAVE_VFS_RW_ITERATE */ #endif /* HAVE_VFS_RW_ITERATE */
@ -835,8 +853,6 @@ const struct file_operations zpl_file_operations = {
.open = zpl_open, .open = zpl_open,
.release = zpl_release, .release = zpl_release,
.llseek = zpl_llseek, .llseek = zpl_llseek,
.read = zpl_read,
.write = zpl_write,
#ifdef HAVE_VFS_RW_ITERATE #ifdef HAVE_VFS_RW_ITERATE
.read_iter = zpl_iter_read, .read_iter = zpl_iter_read,
.write_iter = zpl_iter_write, .write_iter = zpl_iter_write,

View File

@ -458,8 +458,9 @@ tests = ['inuse_004_pos']
post = post =
# DISABLED: needs investigation # DISABLED: needs investigation
#[tests/functional/large_files] # large_files_001_pos
#tests = ['large_files_001_pos'] [tests/functional/large_files]
tests = ['large_files_002_pos']
# DISABLED: needs investigation # DISABLED: needs investigation
#[tests/functional/largest_pool] #[tests/functional/largest_pool]

View File

@ -2,4 +2,5 @@ pkgdatadir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/large_files
dist_pkgdata_SCRIPTS = \ dist_pkgdata_SCRIPTS = \
setup.ksh \ setup.ksh \
cleanup.ksh \ cleanup.ksh \
large_files_001_pos.ksh large_files_001_pos.ksh \
large_files_002_pos.ksh

View File

@ -0,0 +1,55 @@
#!/bin/ksh -p
#
# 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 http://www.opensolaris.org/os/licensing.
# 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
#
#
# Copyright (c) 2015 by Lawrence Livermore National Security, LLC.
# All rights reserved.
#
. $STF_SUITE/include/libtest.shlib
#
# DESCRIPTION:
# Verify 'ulimit -f' file size restrictions are enforced.
#
# STRATEGY:
# 1. Set ulimit file size to unlimited, verify files can be created.
# 2. Reduce ulimit file size, verify the expected error is returned.
#
verify_runnable "both"
log_assert "Verify 'ulimit -f' maximum file size is enforced"
# Verify 'ulimit -f unlimited' works
log_must ulimit -f unlimited
log_must sh -c 'dd if=/dev/zero of=$TESTDIR/ulimit_write_file bs=1M count=2'
log_must sh -c '$TRUNCATE -s2M $TESTDIR/ulimit_trunc_file'
log_must $RM $TESTDIR/ulimit_write_file $TESTDIR/ulimit_trunc_file
# Verify 'ulimit -f <size>' works
log_must ulimit -f 1024
log_mustnot sh -c 'dd if=/dev/zero of=$TESTDIR/ulimit_write_file bs=1M count=2'
log_mustnot sh -c '$TRUNCATE -s2M $TESTDIR/ulimit_trunc_file'
log_must $RM $TESTDIR/ulimit_write_file $TESTDIR/ulimit_trunc_file
log_pass "Successfully enforced 'ulimit -f' maximum file size"