openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity
linux/fs/gfs2/ops_file.c

681 lines
16 KiB
C
Raw Blame History

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
#include <linux/ext2_fs.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
#include <linux/writeback.h>
#include <asm/uaccess.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "lm.h"
#include "log.h"
#include "meta_io.h"
#include "ops_file.h"
#include "ops_vm.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
#include "eaops.h"
/*
* Most fields left uninitialised to catch anybody who tries to
* use them. f_flags set to prevent file_accessed() from touching
* any other part of this. Its use is purely as a flag so that we
* know (in readpage()) whether or not do to locking.
*/
struct file gfs2_internal_file_sentinel = {
.f_flags = O_NOATIME|O_RDONLY,
};
static int gfs2_read_actor(read_descriptor_t *desc, struct page *page,
unsigned long offset, unsigned long size)
{
char *kaddr;
unsigned long count = desc->count;
if (size > count)
size = count;
kaddr = kmap(page);
memcpy(desc->arg.data, kaddr + offset, size);
kunmap(page);
desc->count = count - size;
desc->written += size;
desc->arg.buf += size;
return size;
}
int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
char *buf, loff_t *pos, unsigned size)
{
struct inode *inode = &ip->i_inode;
read_descriptor_t desc;
desc.written = 0;
desc.arg.data = buf;
desc.count = size;
desc.error = 0;
do_generic_mapping_read(inode->i_mapping, ra_state,
&gfs2_internal_file_sentinel, pos, &desc,
gfs2_read_actor);
return desc.written ? desc.written : desc.error;
}
/**
* gfs2_llseek - seek to a location in a file
* @file: the file
* @offset: the offset
* @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
*
* SEEK_END requires the glock for the file because it references the
* file's size.
*
* Returns: The new offset, or errno
*/
static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
{
struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
struct gfs2_holder i_gh;
loff_t error;
if (origin == 2) {
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
&i_gh);
if (!error) {
error = remote_llseek(file, offset, origin);
gfs2_glock_dq_uninit(&i_gh);
}
} else
error = remote_llseek(file, offset, origin);
return error;
}
/**
* gfs2_readdir - Read directory entries from a directory
* @file: The directory to read from
* @dirent: Buffer for dirents
* @filldir: Function used to do the copying
*
* Returns: errno
*/
static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
{
struct inode *dir = file->f_mapping->host;
struct gfs2_inode *dip = GFS2_I(dir);
struct gfs2_holder d_gh;
u64 offset = file->f_pos;
int error;
gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
error = gfs2_glock_nq_atime(&d_gh);
if (error) {
gfs2_holder_uninit(&d_gh);
return error;
}
error = gfs2_dir_read(dir, &offset, dirent, filldir);
gfs2_glock_dq_uninit(&d_gh);
file->f_pos = offset;
return error;
}
/**
* fsflags_cvt
* @table: A table of 32 u32 flags
* @val: a 32 bit value to convert
*
* This function can be used to convert between fsflags values and
* GFS2's own flags values.
*
* Returns: the converted flags
*/
static u32 fsflags_cvt(const u32 *table, u32 val)
{
u32 res = 0;
while(val) {
if (val & 1)
res |= *table;
table++;
val >>= 1;
}
return res;
}
static const u32 fsflags_to_gfs2[32] = {
[3] = GFS2_DIF_SYNC,
[4] = GFS2_DIF_IMMUTABLE,
[5] = GFS2_DIF_APPENDONLY,
[7] = GFS2_DIF_NOATIME,
[12] = GFS2_DIF_EXHASH,
[14] = GFS2_DIF_INHERIT_JDATA,
[20] = GFS2_DIF_INHERIT_DIRECTIO,
};
static const u32 gfs2_to_fsflags[32] = {
[gfs2fl_Sync] = FS_SYNC_FL,
[gfs2fl_Immutable] = FS_IMMUTABLE_FL,
[gfs2fl_AppendOnly] = FS_APPEND_FL,
[gfs2fl_NoAtime] = FS_NOATIME_FL,
[gfs2fl_ExHash] = FS_INDEX_FL,
[gfs2fl_InheritDirectio] = FS_DIRECTIO_FL,
[gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
};
static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int error;
u32 fsflags;
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
error = gfs2_glock_nq_atime(&gh);
if (error)
return error;
fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_di.di_flags);
if (!S_ISDIR(inode->i_mode)) {
if (ip->i_di.di_flags & GFS2_DIF_JDATA)
fsflags |= FS_JOURNAL_DATA_FL;
if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
fsflags |= FS_DIRECTIO_FL;
}
if (put_user(fsflags, ptr))
error = -EFAULT;
gfs2_glock_dq_m(1, &gh);
gfs2_holder_uninit(&gh);
return error;
}
void gfs2_set_inode_flags(struct inode *inode)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_dinode_host *di = &ip->i_di;
unsigned int flags = inode->i_flags;
flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
if (di->di_flags & GFS2_DIF_IMMUTABLE)
flags |= S_IMMUTABLE;
if (di->di_flags & GFS2_DIF_APPENDONLY)
flags |= S_APPEND;
if (di->di_flags & GFS2_DIF_NOATIME)
flags |= S_NOATIME;
if (di->di_flags & GFS2_DIF_SYNC)
flags |= S_SYNC;
inode->i_flags = flags;
}
/* Flags that can be set by user space */
#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \
GFS2_DIF_DIRECTIO| \
GFS2_DIF_IMMUTABLE| \
GFS2_DIF_APPENDONLY| \
GFS2_DIF_NOATIME| \
GFS2_DIF_SYNC| \
GFS2_DIF_SYSTEM| \
GFS2_DIF_INHERIT_DIRECTIO| \
GFS2_DIF_INHERIT_JDATA)
/**
* gfs2_set_flags - set flags on an inode
* @inode: The inode
* @flags: The flags to set
* @mask: Indicates which flags are valid
*
*/
static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct buffer_head *bh;
struct gfs2_holder gh;
int error;
u32 new_flags, flags;
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
if (error)
return error;
flags = ip->i_di.di_flags;
new_flags = (flags & ~mask) | (reqflags & mask);
if ((new_flags ^ flags) == 0)
goto out;
error = -EINVAL;
if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
goto out;
error = -EPERM;
if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
goto out;
if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
goto out;
if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
!capable(CAP_LINUX_IMMUTABLE))
goto out;
if (!IS_IMMUTABLE(inode)) {
error = permission(inode, MAY_WRITE, NULL);
if (error)
goto out;
}
error = gfs2_trans_begin(sdp, RES_DINODE, 0);
if (error)
goto out;
error = gfs2_meta_inode_buffer(ip, &bh);
if (error)
goto out_trans_end;
gfs2_trans_add_bh(ip->i_gl, bh, 1);
ip->i_di.di_flags = new_flags;
gfs2_dinode_out(ip, bh->b_data);
brelse(bh);
gfs2_set_inode_flags(inode);
out_trans_end:
gfs2_trans_end(sdp);
out:
gfs2_glock_dq_uninit(&gh);
return error;
}
static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
{
struct inode *inode = filp->f_path.dentry->d_inode;
u32 fsflags, gfsflags;
if (get_user(fsflags, ptr))
return -EFAULT;
gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
if (!S_ISDIR(inode->i_mode)) {
if (gfsflags & GFS2_DIF_INHERIT_JDATA)
gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
if (gfsflags & GFS2_DIF_INHERIT_DIRECTIO)
gfsflags ^= (GFS2_DIF_DIRECTIO | GFS2_DIF_INHERIT_DIRECTIO);
return do_gfs2_set_flags(filp, gfsflags, ~0);
}
return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
}
static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
switch(cmd) {
case FS_IOC_GETFLAGS:
return gfs2_get_flags(filp, (u32 __user *)arg);
case FS_IOC_SETFLAGS:
return gfs2_set_flags(filp, (u32 __user *)arg);
}
return -ENOTTY;
}
/**
* gfs2_mmap -
* @file: The file to map
* @vma: The VMA which described the mapping
*
* Returns: 0 or error code
*/
static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
struct gfs2_holder i_gh;
int error;
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
error = gfs2_glock_nq_atime(&i_gh);
if (error) {
gfs2_holder_uninit(&i_gh);
return error;
}
/* This is VM_MAYWRITE instead of VM_WRITE because a call
to mprotect() can turn on VM_WRITE later. */
if ((vma->vm_flags & (VM_MAYSHARE | VM_MAYWRITE)) ==
(VM_MAYSHARE | VM_MAYWRITE))
vma->vm_ops = &gfs2_vm_ops_sharewrite;
else
vma->vm_ops = &gfs2_vm_ops_private;
gfs2_glock_dq_uninit(&i_gh);
return error;
}
/**
* gfs2_open - open a file
* @inode: the inode to open
* @file: the struct file for this opening
*
* Returns: errno
*/
static int gfs2_open(struct inode *inode, struct file *file)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder i_gh;
struct gfs2_file *fp;
int error;
fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
if (!fp)
return -ENOMEM;
mutex_init(&fp->f_fl_mutex);
gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
file->private_data = fp;
if (S_ISREG(ip->i_inode.i_mode)) {
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
&i_gh);
if (error)
goto fail;
if (!(file->f_flags & O_LARGEFILE) &&
ip->i_di.di_size > MAX_NON_LFS) {
error = -EFBIG;
goto fail_gunlock;
}
/* Listen to the Direct I/O flag */
if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
file->f_flags |= O_DIRECT;
gfs2_glock_dq_uninit(&i_gh);
}
return 0;
fail_gunlock:
gfs2_glock_dq_uninit(&i_gh);
fail:
file->private_data = NULL;
kfree(fp);
return error;
}
/**
* gfs2_close - called to close a struct file
* @inode: the inode the struct file belongs to
* @file: the struct file being closed
*
* Returns: errno
*/
static int gfs2_close(struct inode *inode, struct file *file)
{
struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
struct gfs2_file *fp;
fp = file->private_data;
file->private_data = NULL;
if (gfs2_assert_warn(sdp, fp))
return -EIO;
kfree(fp);
return 0;
}
/**
* gfs2_fsync - sync the dirty data for a file (across the cluster)
* @file: the file that points to the dentry (we ignore this)
* @dentry: the dentry that points to the inode to sync
*
* The VFS will flush "normal" data for us. We only need to worry
* about metadata here. For journaled data, we just do a log flush
* as we can't avoid it. Otherwise we can just bale out if datasync
* is set. For stuffed inodes we must flush the log in order to
* ensure that all data is on disk.
*
* The call to write_inode_now() is there to write back metadata and
* the inode itself. It does also try and write the data, but thats
* (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
* for us.
*
* Returns: errno
*/
static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
{
struct inode *inode = dentry->d_inode;
int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
int ret = 0;
if (gfs2_is_jdata(GFS2_I(inode))) {
gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
return 0;
}
if (sync_state != 0) {
if (!datasync)
ret = write_inode_now(inode, 0);
if (gfs2_is_stuffed(GFS2_I(inode)))
gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
}
return ret;
}
/**
* gfs2_setlease - acquire/release a file lease
* @file: the file pointer
* @arg: lease type
* @fl: file lock
*
* Returns: errno
*/
static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
{
struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
/*
* We don't currently have a way to enforce a lease across the whole
* cluster; until we do, disable leases (by just returning -EINVAL),
* unless the administrator has requested purely local locking.
*/
if (!sdp->sd_args.ar_localflocks)
return -EINVAL;
return generic_setlease(file, arg, fl);
}
/**
* gfs2_lock - acquire/release a posix lock on a file
* @file: the file pointer
* @cmd: either modify or retrieve lock state, possibly wait
* @fl: type and range of lock
*
* Returns: errno
*/
static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
{
struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
struct lm_lockname name =
{ .ln_number = ip->i_no_addr,
.ln_type = LM_TYPE_PLOCK };
if (!(fl->fl_flags & FL_POSIX))
return -ENOLCK;
if (__mandatory_lock(&ip->i_inode))
return -ENOLCK;
if (sdp->sd_args.ar_localflocks) {
if (IS_GETLK(cmd)) {
posix_test_lock(file, fl);
return 0;
} else {
return posix_lock_file_wait(file, fl);
}
}
if (cmd == F_CANCELLK) {
/* Hack: */
cmd = F_SETLK;
fl->fl_type = F_UNLCK;
}
if (IS_GETLK(cmd))
return gfs2_lm_plock_get(sdp, &name, file, fl);
else if (fl->fl_type == F_UNLCK)
return gfs2_lm_punlock(sdp, &name, file, fl);
else
return gfs2_lm_plock(sdp, &name, file, cmd, fl);
}
static int do_flock(struct file *file, int cmd, struct file_lock *fl)
{
struct gfs2_file *fp = file->private_data;
struct gfs2_holder *fl_gh = &fp->f_fl_gh;
struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
struct gfs2_glock *gl;
unsigned int state;
int flags;
int error = 0;
state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE
| GL_FLOCK;
mutex_lock(&fp->f_fl_mutex);
gl = fl_gh->gh_gl;
if (gl) {
if (fl_gh->gh_state == state)
goto out;
flock_lock_file_wait(file,
&(struct file_lock){.fl_type = F_UNLCK});
gfs2_glock_dq_wait(fl_gh);
gfs2_holder_reinit(state, flags, fl_gh);
} else {
error = gfs2_glock_get(GFS2_SB(&ip->i_inode),
ip->i_no_addr, &gfs2_flock_glops,
CREATE, &gl);
if (error)
goto out;
gfs2_holder_init(gl, state, flags, fl_gh);
gfs2_glock_put(gl);
}
error = gfs2_glock_nq(fl_gh);
if (error) {
gfs2_holder_uninit(fl_gh);
if (error == GLR_TRYFAILED)
error = -EAGAIN;
} else {
error = flock_lock_file_wait(file, fl);
gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
}
out:
mutex_unlock(&fp->f_fl_mutex);
return error;
}
static void do_unflock(struct file *file, struct file_lock *fl)
{
struct gfs2_file *fp = file->private_data;
struct gfs2_holder *fl_gh = &fp->f_fl_gh;
mutex_lock(&fp->f_fl_mutex);
flock_lock_file_wait(file, fl);
if (fl_gh->gh_gl)
gfs2_glock_dq_uninit(fl_gh);
mutex_unlock(&fp->f_fl_mutex);
}
/**
* gfs2_flock - acquire/release a flock lock on a file
* @file: the file pointer
* @cmd: either modify or retrieve lock state, possibly wait
* @fl: type and range of lock
*
* Returns: errno
*/
static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
{
struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
if (!(fl->fl_flags & FL_FLOCK))
return -ENOLCK;
if (__mandatory_lock(&ip->i_inode))
return -ENOLCK;
if (sdp->sd_args.ar_localflocks)
return flock_lock_file_wait(file, fl);
if (fl->fl_type == F_UNLCK) {
do_unflock(file, fl);
return 0;
} else {
return do_flock(file, cmd, fl);
}
}
const struct file_operations gfs2_file_fops = {
.llseek = gfs2_llseek,
.read = do_sync_read,
.aio_read = generic_file_aio_read,
.write = do_sync_write,
.aio_write = generic_file_aio_write,
.unlocked_ioctl = gfs2_ioctl,
.mmap = gfs2_mmap,
.open = gfs2_open,
.release = gfs2_close,
.fsync = gfs2_fsync,
.lock = gfs2_lock,
.flock = gfs2_flock,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.setlease = gfs2_setlease,
};
const struct file_operations gfs2_dir_fops = {
.readdir = gfs2_readdir,
.unlocked_ioctl = gfs2_ioctl,
.open = gfs2_open,
.release = gfs2_close,
.fsync = gfs2_fsync,
.lock = gfs2_lock,
.flock = gfs2_flock,
};
Reference in New Issue View Git Blame Copy Permalink