linux/fs/jffs2/file.c
KaiGai Kohei aa98d7cf59 [JFFS2][XATTR] XATTR support on JFFS2 (version. 5)
This attached patches provide xattr support including POSIX-ACL and
SELinux support on JFFS2 (version.5).

There are some significant differences from previous version posted
at last December.
The biggest change is addition of EBS(Erase Block Summary) support.
Currently, both kernel and usermode utility (sumtool) can recognize
xattr nodes which have JFFS2_NODETYPE_XATTR/_XREF nodetype.

In addition, some bugs are fixed.
- A potential race condition was fixed.
- Unexpected fail when updating a xattr by same name/value pair was fixed.
- A bug when removing xattr name/value pair was fixed.

The fundamental structures (such as using two new nodetypes and exclusion
mechanism by rwsem) are unchanged. But most of implementation were reviewed
and updated if necessary.
Espacially, we had to change several internal implementations related to
load_xattr_datum() to avoid a potential race condition.

[1/2] xattr_on_jffs2.kernel.version-5.patch
[2/2] xattr_on_jffs2.utils.version-5.patch

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-13 15:09:47 +09:00

290 lines
8.3 KiB
C

/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2001-2003 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@infradead.org>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
* $Id: file.c,v 1.104 2005/10/18 23:29:35 tpoynor Exp $
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include "nodelist.h"
static int jffs2_commit_write (struct file *filp, struct page *pg,
unsigned start, unsigned end);
static int jffs2_prepare_write (struct file *filp, struct page *pg,
unsigned start, unsigned end);
static int jffs2_readpage (struct file *filp, struct page *pg);
int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
{
struct inode *inode = dentry->d_inode;
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
/* Trigger GC to flush any pending writes for this inode */
jffs2_flush_wbuf_gc(c, inode->i_ino);
return 0;
}
const struct file_operations jffs2_file_operations =
{
.llseek = generic_file_llseek,
.open = generic_file_open,
.read = generic_file_read,
.write = generic_file_write,
.ioctl = jffs2_ioctl,
.mmap = generic_file_readonly_mmap,
.fsync = jffs2_fsync,
.sendfile = generic_file_sendfile
};
/* jffs2_file_inode_operations */
struct inode_operations jffs2_file_inode_operations =
{
.permission = jffs2_permission,
.setattr = jffs2_setattr,
.setxattr = jffs2_setxattr,
.getxattr = jffs2_getxattr,
.listxattr = jffs2_listxattr,
.removexattr = jffs2_removexattr
};
struct address_space_operations jffs2_file_address_operations =
{
.readpage = jffs2_readpage,
.prepare_write =jffs2_prepare_write,
.commit_write = jffs2_commit_write
};
static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
{
struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
unsigned char *pg_buf;
int ret;
D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
BUG_ON(!PageLocked(pg));
pg_buf = kmap(pg);
/* FIXME: Can kmap fail? */
ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
if (ret) {
ClearPageUptodate(pg);
SetPageError(pg);
} else {
SetPageUptodate(pg);
ClearPageError(pg);
}
flush_dcache_page(pg);
kunmap(pg);
D2(printk(KERN_DEBUG "readpage finished\n"));
return 0;
}
int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
{
int ret = jffs2_do_readpage_nolock(inode, pg);
unlock_page(pg);
return ret;
}
static int jffs2_readpage (struct file *filp, struct page *pg)
{
struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
int ret;
down(&f->sem);
ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
up(&f->sem);
return ret;
}
static int jffs2_prepare_write (struct file *filp, struct page *pg,
unsigned start, unsigned end)
{
struct inode *inode = pg->mapping->host;
struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
int ret = 0;
D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
if (pageofs > inode->i_size) {
/* Make new hole frag from old EOF to new page */
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
struct jffs2_raw_inode ri;
struct jffs2_full_dnode *fn;
uint32_t phys_ofs, alloc_len;
D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
(unsigned int)inode->i_size, pageofs));
ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len,
ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
if (ret)
return ret;
down(&f->sem);
memset(&ri, 0, sizeof(ri));
ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
ri.totlen = cpu_to_je32(sizeof(ri));
ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
ri.ino = cpu_to_je32(f->inocache->ino);
ri.version = cpu_to_je32(++f->highest_version);
ri.mode = cpu_to_jemode(inode->i_mode);
ri.uid = cpu_to_je16(inode->i_uid);
ri.gid = cpu_to_je16(inode->i_gid);
ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
ri.offset = cpu_to_je32(inode->i_size);
ri.dsize = cpu_to_je32(pageofs - inode->i_size);
ri.csize = cpu_to_je32(0);
ri.compr = JFFS2_COMPR_ZERO;
ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
ri.data_crc = cpu_to_je32(0);
fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
if (IS_ERR(fn)) {
ret = PTR_ERR(fn);
jffs2_complete_reservation(c);
up(&f->sem);
return ret;
}
ret = jffs2_add_full_dnode_to_inode(c, f, fn);
if (f->metadata) {
jffs2_mark_node_obsolete(c, f->metadata->raw);
jffs2_free_full_dnode(f->metadata);
f->metadata = NULL;
}
if (ret) {
D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
jffs2_mark_node_obsolete(c, fn->raw);
jffs2_free_full_dnode(fn);
jffs2_complete_reservation(c);
up(&f->sem);
return ret;
}
jffs2_complete_reservation(c);
inode->i_size = pageofs;
up(&f->sem);
}
/* Read in the page if it wasn't already present, unless it's a whole page */
if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
down(&f->sem);
ret = jffs2_do_readpage_nolock(inode, pg);
up(&f->sem);
}
D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
return ret;
}
static int jffs2_commit_write (struct file *filp, struct page *pg,
unsigned start, unsigned end)
{
/* Actually commit the write from the page cache page we're looking at.
* For now, we write the full page out each time. It sucks, but it's simple
*/
struct inode *inode = pg->mapping->host;
struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
struct jffs2_raw_inode *ri;
unsigned aligned_start = start & ~3;
int ret = 0;
uint32_t writtenlen = 0;
D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
if (!start && end == PAGE_CACHE_SIZE) {
/* We need to avoid deadlock with page_cache_read() in
jffs2_garbage_collect_pass(). So we have to mark the
page up to date, to prevent page_cache_read() from
trying to re-lock it. */
SetPageUptodate(pg);
}
ri = jffs2_alloc_raw_inode();
if (!ri) {
D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
return -ENOMEM;
}
/* Set the fields that the generic jffs2_write_inode_range() code can't find */
ri->ino = cpu_to_je32(inode->i_ino);
ri->mode = cpu_to_jemode(inode->i_mode);
ri->uid = cpu_to_je16(inode->i_uid);
ri->gid = cpu_to_je16(inode->i_gid);
ri->isize = cpu_to_je32((uint32_t)inode->i_size);
ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
/* In 2.4, it was already kmapped by generic_file_write(). Doesn't
hurt to do it again. The alternative is ifdefs, which are ugly. */
kmap(pg);
ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
(pg->index << PAGE_CACHE_SHIFT) + aligned_start,
end - aligned_start, &writtenlen);
kunmap(pg);
if (ret) {
/* There was an error writing. */
SetPageError(pg);
}
/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
if (writtenlen < (start&3))
writtenlen = 0;
else
writtenlen -= (start&3);
if (writtenlen) {
if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
inode->i_blocks = (inode->i_size + 511) >> 9;
inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
}
}
jffs2_free_raw_inode(ri);
if (start+writtenlen < end) {
/* generic_file_write has written more to the page cache than we've
actually written to the medium. Mark the page !Uptodate so that
it gets reread */
D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
SetPageError(pg);
ClearPageUptodate(pg);
}
D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
return start+writtenlen==end?0:ret;
}