--- /dev/null
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.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_write_end(struct file *filp, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *pg, void *fsdata);
+static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata);
+static int jffs2_readpage (struct file *filp, struct page *pg);
+
+int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
+{
+ struct inode *inode = filp->f_mapping->host;
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
+ int ret;
+
+ ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (ret)
+ return ret;
+
+ mutex_lock(&inode->i_mutex);
+ /* Trigger GC to flush any pending writes for this inode */
+ jffs2_flush_wbuf_gc(c, inode->i_ino);
+ mutex_unlock(&inode->i_mutex);
+
+ return 0;
+}
+
+const struct file_operations jffs2_file_operations =
+{
+ .llseek = generic_file_llseek,
+ .open = generic_file_open,
+ .read_iter = generic_file_read_iter,
+ .write_iter = generic_file_write_iter,
+ .unlocked_ioctl=jffs2_ioctl,
+ .mmap = generic_file_readonly_mmap,
+ .fsync = jffs2_fsync,
+ .splice_read = generic_file_splice_read,
+};
+
+/* jffs2_file_inode_operations */
+
+const struct inode_operations jffs2_file_inode_operations =
+{
+ .get_acl = jffs2_get_acl,
+ .set_acl = jffs2_set_acl,
+ .setattr = jffs2_setattr,
+ .setxattr = jffs2_setxattr,
+ .getxattr = jffs2_getxattr,
+ .listxattr = jffs2_listxattr,
+ .removexattr = jffs2_removexattr
+};
+
+const struct address_space_operations jffs2_file_address_operations =
+{
+ .readpage = jffs2_readpage,
+ .write_begin = jffs2_write_begin,
+ .write_end = jffs2_write_end,
+};
+
+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;
+
+ jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n",
+ __func__, 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);
+
+ jffs2_dbg(2, "readpage finished\n");
+ return ret;
+}
+
+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;
+
+ mutex_lock(&f->sem);
+ ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
+ mutex_unlock(&f->sem);
+ return ret;
+}
+
+static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct page *pg;
+ struct inode *inode = 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;
+ uint32_t alloc_len = 0;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ uint32_t pageofs = index << PAGE_CACHE_SHIFT;
+ int ret = 0;
+
+ jffs2_dbg(1, "%s()\n", __func__);
+
+ if (pageofs > inode->i_size) {
+ ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
+ ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
+ if (ret)
+ return ret;
+ }
+
+ mutex_lock(&f->sem);
+ pg = grab_cache_page_write_begin(mapping, index, flags);
+ if (!pg) {
+ if (alloc_len)
+ jffs2_complete_reservation(c);
+ mutex_unlock(&f->sem);
+ return -ENOMEM;
+ }
+ *pagep = pg;
+
+ if (alloc_len) {
+ /* Make new hole frag from old EOF to new page */
+ struct jffs2_full_dnode *fn;
+
+ jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
+ (unsigned int)inode->i_size, pageofs);
+
+ 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(i_uid_read(inode));
+ ri.gid = cpu_to_je16(i_gid_read(inode));
+ 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, ALLOC_NORMAL);
+
+ if (IS_ERR(fn)) {
+ ret = PTR_ERR(fn);
+ jffs2_complete_reservation(c);
+ goto out_page;
+ }
+ 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) {
+ jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
+ ret);
+ jffs2_mark_node_obsolete(c, fn->raw);
+ jffs2_free_full_dnode(fn);
+ jffs2_complete_reservation(c);
+ goto out_page;
+ }
+ jffs2_complete_reservation(c);
+ inode->i_size = pageofs;
+ }
+
+ /*
+ * Read in the page if it wasn't already present. Cannot optimize away
+ * the whole page write case until jffs2_write_end can handle the
+ * case of a short-copy.
+ */
+ if (!PageUptodate(pg)) {
+ ret = jffs2_do_readpage_nolock(inode, pg);
+ if (ret)
+ goto out_page;
+ }
+ mutex_unlock(&f->sem);
+ jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
+ return ret;
+
+out_page:
+ unlock_page(pg);
+ page_cache_release(pg);
+ mutex_unlock(&f->sem);
+ return ret;
+}
+
+static int jffs2_write_end(struct file *filp, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *pg, void *fsdata)
+{
+ /* 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 = 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 start = pos & (PAGE_CACHE_SIZE - 1);
+ unsigned end = start + copied;
+ unsigned aligned_start = start & ~3;
+ int ret = 0;
+ uint32_t writtenlen = 0;
+
+ jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
+ __func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT,
+ start, end, pg->flags);
+
+ /* We need to avoid deadlock with page_cache_read() in
+ jffs2_garbage_collect_pass(). So the page must be
+ up to date to prevent page_cache_read() from trying
+ to re-lock it. */
+ BUG_ON(!PageUptodate(pg));
+
+ if (end == PAGE_CACHE_SIZE) {
+ /* When writing out the end of a page, write out the
+ _whole_ page. This helps to reduce the number of
+ nodes in files which have many short writes, like
+ syslog files. */
+ aligned_start = 0;
+ }
+
+ ri = jffs2_alloc_raw_inode();
+
+ if (!ri) {
+ jffs2_dbg(1, "%s(): Allocation of raw inode failed\n",
+ __func__);
+ unlock_page(pg);
+ page_cache_release(pg);
+ 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(i_uid_read(inode));
+ ri->gid = cpu_to_je16(i_gid_read(inode));
+ 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 */
+ writtenlen -= min(writtenlen, (start - aligned_start));
+
+ if (writtenlen) {
+ if (inode->i_size < pos + writtenlen) {
+ inode->i_size = pos + 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 */
+ jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n",
+ __func__);
+ SetPageError(pg);
+ ClearPageUptodate(pg);
+ }
+
+ jffs2_dbg(1, "%s() returning %d\n",
+ __func__, writtenlen > 0 ? writtenlen : ret);
+ unlock_page(pg);
+ page_cache_release(pg);
+ return writtenlen > 0 ? writtenlen : ret;
+}
Code Review / kvmfornfv.git / blobdiff