/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 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 v.2.
*/
#include <linux/sched.h>
#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/smp_lock.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
#include <asm/semaphore.h>
#include <asm/uaccess.h>
#include "gfs2.h"
#include "lm_interface.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"
/* "bad" is for NFS support */
struct filldir_bad_entry {
char *fbe_name;
unsigned int fbe_length;
uint64_t fbe_offset;
struct gfs2_inum fbe_inum;
unsigned int fbe_type;
};
struct filldir_bad {
struct gfs2_sbd *fdb_sbd;
struct filldir_bad_entry *fdb_entry;
unsigned int fdb_entry_num;
unsigned int fdb_entry_off;
char *fdb_name;
unsigned int fdb_name_size;
unsigned int fdb_name_off;
};
/* For regular, non-NFS */
struct filldir_reg {
struct gfs2_sbd *fdr_sbd;
int fdr_prefetch;
filldir_t fdr_filldir;
void *fdr_opaque;
};
/*
* 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_sentinal = {
.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.buf, 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_vnode;
read_descriptor_t desc;
desc.written = 0;
desc.arg.buf = buf;
desc.count = size;
desc.error = 0;
do_generic_mapping_read(inode->i_mapping, ra_state,
&gfs2_internal_file_sentinal, 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 = file->f_mapping->host->u.generic_ip;
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;
}
static ssize_t gfs2_direct_IO_read(struct kiocb *iocb, const struct iovec *iov,
loff_t offset, unsigned long nr_segs)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
ssize_t retval;
retval = filemap_write_and_wait(mapping);
if (retval == 0) {
retval = mapping->a_ops->direct_IO(READ, iocb, iov, offset,
nr_segs);
}
return retval;
}
/**
* __gfs2_file_aio_read - The main GFS2 read function
*
* N.B. This is almost, but not quite the same as __generic_file_aio_read()
* the important subtle different being that inode->i_size isn't valid
* unless we are holding a lock, and we do this _only_ on the O_DIRECT
* path since otherwise locking is done entirely at the page cache
* layer.
*/
static ssize_t __gfs2_file_aio_read(struct kiocb *iocb,
const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
struct file *filp = iocb->ki_filp;
struct gfs2_inode *ip = filp->f_mapping->host->u.generic_ip;
struct gfs2_holder gh;
ssize_t retval;
unsigned long seg;
size_t count;
count = 0;
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *iv = &iov[seg];
/*
* If any segment has a negative length, or the cumulative
* length ever wraps negative then return -EINVAL.
*/
count += iv->iov_len;
if (unlikely((ssize_t)(count|iv->iov_len) < 0))
return -EINVAL;
if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
continue;
if (seg == 0)
return -EFAULT;
nr_segs = seg;
count -= iv->iov_len; /* This segment is no good */
break;
}
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (filp->f_flags & O_DIRECT) {
loff_t pos = *ppos, size;
struct address_space *mapping;
struct inode *inode;
mapping = filp->f_mapping;
inode = mapping->host;
retval = 0;
if (!count)
goto out; /* skip atime */
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
retval = gfs2_glock_nq_m_atime(1, &gh);
if (retval)
goto out;
if (gfs2_is_stuffed(ip)) {
gfs2_glock_dq_m(1, &gh);
gfs2_holder_uninit(&gh);
goto fallback_to_normal;
}
size = i_size_read(inode);
if (pos < size) {
retval = gfs2_direct_IO_read(iocb, iov, pos, nr_segs);
if (retval > 0 && !is_sync_kiocb(iocb))
retval = -EIOCBQUEUED;
if (retval > 0)
*ppos = pos + retval;
}
file_accessed(filp);
gfs2_glock_dq_m(1, &gh);
gfs2_holder_uninit(&gh);
goto out;
}
fallback_to_normal:
retval = 0;
if (count) {
for (seg = 0; seg < nr_segs; seg++) {
read_descriptor_t desc;
desc.written = 0;
desc.arg.buf = iov[seg].iov_base;
desc.count = iov[seg].iov_len;
if (desc.count == 0)
continue;
desc.error = 0;
do_generic_file_read(filp,ppos,&desc,file_read_actor);
retval += desc.written;
if (desc.error) {
retval = retval ?: desc.error;
break;
}
}
}
out:
return retval;
}
/**
* gfs2_read - Read bytes from a file
* @file: The file to read from
* @buf: The buffer to copy into
* @size: The amount of data requested
* @offset: The current file offset
*
* Outputs: Offset - updated according to number of bytes read
*
* Returns: The number of bytes read, errno on failure
*/
static ssize_t gfs2_read(struct file *filp, char __user *buf, size_t size,
loff_t *offset)
{
struct iovec local_iov = { .iov_base = buf, .iov_len = size };
struct kiocb kiocb;
ssize_t ret;
init_sync_kiocb(&kiocb, filp);
ret = __gfs2_file_aio_read(&kiocb, &local_iov, 1, offset);
if (-EIOCBQUEUED == ret)
ret = wait_on_sync_kiocb(&kiocb);
return ret;
}
static ssize_t gfs2_file_readv(struct file *filp, const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
struct kiocb kiocb;
ssize_t ret;
init_sync_kiocb(&kiocb, filp);
ret = __gfs2_file_aio_read(&kiocb, iov, nr_segs, ppos);
if (-EIOCBQUEUED == ret)
ret = wait_on_sync_kiocb(&kiocb);
return ret;
}
static ssize_t gfs2_file_aio_read(struct kiocb *iocb, char __user *buf,
size_t count, loff_t pos)
{
struct iovec local_iov = { .iov_base = buf, .iov_len = count };
BUG_ON(iocb->ki_pos != pos);
return __gfs2_file_aio_read(iocb, &local_iov, 1, &iocb->ki_pos);
}
/**
* filldir_reg_func - Report a directory entry to the caller of gfs2_dir_read()
* @opaque: opaque data used by the function
* @name: the name of the directory entry
* @length: the length of the name
* @offset: the entry's offset in the directory
* @inum: the inode number the entry points to
* @type: the type of inode the entry points to
*
* Returns: 0 on success, 1 if buffer full
*/
static int filldir_reg_func(void *opaque, const char *name, unsigned int length,
uint64_t offset, struct gfs2_inum *inum,
unsigned int type)
{
struct filldir_reg *fdr = (struct filldir_reg *)opaque;
struct gfs2_sbd *sdp = fdr->fdr_sbd;
int error;
error = fdr->fdr_filldir(fdr->fdr_opaque, name, length, offset,
inum->no_formal_ino, type);
if (error)
return 1;
if (fdr->fdr_prefetch && !(length == 1 && *name == '.')) {
gfs2_glock_prefetch_num(sdp,
inum->no_addr, &gfs2_inode_glops,
LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
gfs2_glock_prefetch_num(sdp,
inum->no_addr, &gfs2_iopen_glops,
LM_ST_SHARED, LM_FLAG_TRY);
}
return 0;
}
/**
* readdir_reg - 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 readdir_reg(struct file *file, void *dirent, filldir_t filldir)
{
struct gfs2_inode *dip = file->f_mapping->host->u.generic_ip;
struct filldir_reg fdr;
struct gfs2_holder d_gh;
uint64_t offset = file->f_pos;
int error;
fdr.fdr_sbd = dip->i_sbd;
fdr.fdr_prefetch = 1;
fdr.fdr_filldir = filldir;
fdr.fdr_opaque = dirent;
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(dip, &offset, &fdr, filldir_reg_func);
gfs2_glock_dq_uninit(&d_gh);
file->f_pos = offset;
return error;
}
/**
* filldir_bad_func - Report a directory entry to the caller of gfs2_dir_read()
* @opaque: opaque data used by the function
* @name: the name of the directory entry
* @length: the length of the name
* @offset: the entry's offset in the directory
* @inum: the inode number the entry points to
* @type: the type of inode the entry points to
*
* For supporting NFS.
*
* Returns: 0 on success, 1 if buffer full
*/
static int filldir_bad_func(void *opaque, const char *name, unsigned int length,
uint64_t offset, struct gfs2_inum *inum,
unsigned int type)
{
struct filldir_bad *fdb = (struct filldir_bad *)opaque;
struct gfs2_sbd *sdp = fdb->fdb_sbd;
struct filldir_bad_entry *fbe;
if (fdb->fdb_entry_off == fdb->fdb_entry_num ||
fdb->fdb_name_off + length > fdb->fdb_name_size)
return 1;
fbe = &fdb->fdb_entry[fdb->fdb_entry_off];
fbe->fbe_name = fdb->fdb_name + fdb->fdb_name_off;
memcpy(fbe->fbe_name, name, length);
fbe->fbe_length = length;
fbe->fbe_offset = offset;
fbe->fbe_inum = *inum;
fbe->fbe_type = type;
fdb->fdb_entry_off++;
fdb->fdb_name_off += length;
if (!(length == 1 && *name == '.')) {
gfs2_glock_prefetch_num(sdp,
inum->no_addr, &gfs2_inode_glops,
LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
gfs2_glock_prefetch_num(sdp,
inum->no_addr, &gfs2_iopen_glops,
LM_ST_SHARED, LM_FLAG_TRY);
}
return 0;
}
/**
* readdir_bad - Read directory entries from a directory
* @file: The directory to read from
* @dirent: Buffer for dirents
* @filldir: Function used to do the copying
*
* For supporting NFS.
*
* Returns: errno
*/
static int readdir_bad(struct file *file, void *dirent, filldir_t filldir)
{
struct gfs2_inode *dip = file->f_mapping->host->u.generic_ip;
struct gfs2_sbd *sdp = dip->i_sbd;
struct filldir_reg fdr;
unsigned int entries, size;
struct filldir_bad *fdb;
struct gfs2_holder d_gh;
uint64_t offset = file->f_pos;
unsigned int x;
struct filldir_bad_entry *fbe;
int error;
entries = gfs2_tune_get(sdp, gt_entries_per_readdir);
size = sizeof(struct filldir_bad) +
entries * (sizeof(struct filldir_bad_entry) + GFS2_FAST_NAME_SIZE);
fdb = kzalloc(size, GFP_KERNEL);
if (!fdb)
return -ENOMEM;
fdb->fdb_sbd = sdp;
fdb->fdb_entry = (struct filldir_bad_entry *)(fdb + 1);
fdb->fdb_entry_num = entries;
fdb->fdb_name = ((char *)fdb) + sizeof(struct filldir_bad) +
entries * sizeof(struct filldir_bad_entry);
fdb->fdb_name_size = entries * GFS2_FAST_NAME_SIZE;
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);
goto out;
}
error = gfs2_dir_read(dip, &offset, fdb, filldir_bad_func);
gfs2_glock_dq_uninit(&d_gh);
fdr.fdr_sbd = sdp;
fdr.fdr_prefetch = 0;
fdr.fdr_filldir = filldir;
fdr.fdr_opaque = dirent;
for (x = 0; x < fdb->fdb_entry_off; x++) {
fbe = &fdb->fdb_entry[x];
error = filldir_reg_func(&fdr,
fbe->fbe_name, fbe->fbe_length,
fbe->fbe_offset,
&fbe->fbe_inum, fbe->fbe_type);
if (error) {
file->f_pos = fbe->fbe_offset;
error = 0;
goto out;
}
}
file->f_pos = offset;
out:
kfree(fdb);
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)
{
int error;
if (strcmp(current->comm, "nfsd") != 0)
error = readdir_reg(file, dirent, filldir);
else
error = readdir_bad(file, dirent, filldir);
return error;
}
/**
* 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 = file->f_mapping->host->u.generic_ip;
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 = inode->u.generic_ip;
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);
fp->f_inode = ip;
fp->f_vfile = file;
gfs2_assert_warn(ip->i_sbd, !file->private_data);
file->private_data = fp;
if (S_ISREG(ip->i_di.di_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
*
* Returns: errno
*/
static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
{
struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;
gfs2_log_flush_glock(ip->i_gl);
return 0;
}
/**
* 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 = file->f_mapping->host->u.generic_ip;
struct gfs2_sbd *sdp = ip->i_sbd;
struct lm_lockname name =
{ .ln_number = ip->i_num.no_addr,
.ln_type = LM_TYPE_PLOCK };
if (!(fl->fl_flags & FL_POSIX))
return -ENOLCK;
if ((ip->i_di.di_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
return -ENOLCK;
if (sdp->sd_args.ar_localflocks) {
if (IS_GETLK(cmd)) {
struct file_lock *tmp;
lock_kernel();
tmp = posix_test_lock(file, fl);
fl->fl_type = F_UNLCK;
if (tmp)
memcpy(fl, tmp, sizeof(struct file_lock));
unlock_kernel();
return 0;
} else {
int error;
lock_kernel();
error = posix_lock_file_wait(file, fl);
unlock_kernel();
return error;
}
}
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);
}
/**
* gfs2_sendfile - Send bytes to a file or socket
* @in_file: The file to read from
* @out_file: The file to write to
* @count: The amount of data
* @offset: The beginning file offset
*
* Outputs: offset - updated according to number of bytes read
*
* Returns: The number of bytes sent, errno on failure
*/
static ssize_t gfs2_sendfile(struct file *in_file, loff_t *offset, size_t count,
read_actor_t actor, void *target)
{
return generic_file_sendfile(in_file, offset, count, actor, target);
}
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 = fp->f_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;
mutex_lock(&fp->f_fl_mutex);
gl = fl_gh->gh_gl;
if (gl) {
if (fl_gh->gh_state == state)
goto out;
gfs2_glock_hold(gl);
flock_lock_file_wait(file,
&(struct file_lock){.fl_type = F_UNLCK});
gfs2_glock_dq_uninit(fl_gh);
} else {
error = gfs2_glock_get(ip->i_sbd,
ip->i_num.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(ip->i_sbd, !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 = file->f_mapping->host->u.generic_ip;
struct gfs2_sbd *sdp = ip->i_sbd;
if (!(fl->fl_flags & FL_FLOCK))
return -ENOLCK;
if ((ip->i_di.di_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
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);
}
struct file_operations gfs2_file_fops = {
.llseek = gfs2_llseek,
.read = gfs2_read,
.readv = gfs2_file_readv,
.aio_read = gfs2_file_aio_read,
.write = generic_file_write,
.writev = generic_file_writev,
.aio_write = generic_file_aio_write,
.mmap = gfs2_mmap,
.open = gfs2_open,
.release = gfs2_close,
.fsync = gfs2_fsync,
.lock = gfs2_lock,
.sendfile = gfs2_sendfile,
.flock = gfs2_flock,
};
struct file_operations gfs2_dir_fops = {
.readdir = gfs2_readdir,
.open = gfs2_open,
.release = gfs2_close,
.fsync = gfs2_fsync,
.lock = gfs2_lock,
.flock = gfs2_flock,
};
