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-rw-r--r--fs/jffs2/file.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
new file mode 100644
index 0000000..0c607c1
--- /dev/null
+++ b/fs/jffs2/file.c
@@ -0,0 +1,290 @@
+/*
+ * 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 1.99 2004/11/16 20:36:11 dwmw2 Exp $
+ *
+ */
+
+#include <linux/version.h>
+#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"
+
+extern int generic_file_open(struct inode *, struct file *) __attribute__((weak));
+extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) __attribute__((weak));
+
+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;
+}
+
+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,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,29)
+ .sendfile = generic_file_sendfile
+#endif
+};
+
+/* jffs2_file_inode_operations */
+
+struct inode_operations jffs2_file_inode_operations =
+{
+ .setattr = jffs2_setattr
+};
+
+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));
+
+ if (!PageLocked(pg))
+ PAGE_BUG(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);
+ 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",writtenlen?writtenlen:ret));
+ return writtenlen?writtenlen:ret;
+}
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