Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 228 insertions, 0 deletions

diff --git a/fs/jffs2/read.c b/fs/jffs2/read.c
new file mode 100644
index 000000000..0b042b1fc
--- /dev/null
+++ b/fs/jffs2/read.c
@@ -0,0 +1,228 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ *
+ * 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/slab.h>
+#include <linux/crc32.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/compiler.h>
+#include "nodelist.h"
+#include "compr.h"
+
+int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
+		     struct jffs2_full_dnode *fd, unsigned char *buf,
+		     int ofs, int len)
+{
+	struct jffs2_raw_inode *ri;
+	size_t readlen;
+	uint32_t crc;
+	unsigned char *decomprbuf = NULL;
+	unsigned char *readbuf = NULL;
+	int ret = 0;
+
+	ri = jffs2_alloc_raw_inode();
+	if (!ri)
+		return -ENOMEM;
+
+	ret = jffs2_flash_read(c, ref_offset(fd->raw), sizeof(*ri), &readlen, (char *)ri);
+	if (ret) {
+		jffs2_free_raw_inode(ri);
+		pr_warn("Error reading node from 0x%08x: %d\n",
+			ref_offset(fd->raw), ret);
+		return ret;
+	}
+	if (readlen != sizeof(*ri)) {
+		jffs2_free_raw_inode(ri);
+		pr_warn("Short read from 0x%08x: wanted 0x%zx bytes, got 0x%zx\n",
+			ref_offset(fd->raw), sizeof(*ri), readlen);
+		return -EIO;
+	}
+	crc = crc32(0, ri, sizeof(*ri)-8);
+
+	jffs2_dbg(1, "Node read from %08x: node_crc %08x, calculated CRC %08x. dsize %x, csize %x, offset %x, buf %p\n",
+		  ref_offset(fd->raw), je32_to_cpu(ri->node_crc),
+		  crc, je32_to_cpu(ri->dsize), je32_to_cpu(ri->csize),
+		  je32_to_cpu(ri->offset), buf);
+	if (crc != je32_to_cpu(ri->node_crc)) {
+		pr_warn("Node CRC %08x != calculated CRC %08x for node at %08x\n",
+			je32_to_cpu(ri->node_crc), crc, ref_offset(fd->raw));
+		ret = -EIO;
+		goto out_ri;
+	}
+	/* There was a bug where we wrote hole nodes out with csize/dsize
+	   swapped. Deal with it */
+	if (ri->compr == JFFS2_COMPR_ZERO && !je32_to_cpu(ri->dsize) &&
+	    je32_to_cpu(ri->csize)) {
+		ri->dsize = ri->csize;
+		ri->csize = cpu_to_je32(0);
+	}
+
+	D1(if(ofs + len > je32_to_cpu(ri->dsize)) {
+			pr_warn("jffs2_read_dnode() asked for %d bytes at %d from %d-byte node\n",
+				len, ofs, je32_to_cpu(ri->dsize));
+		ret = -EINVAL;
+		goto out_ri;
+	});
+
+
+	if (ri->compr == JFFS2_COMPR_ZERO) {
+		memset(buf, 0, len);
+		goto out_ri;
+	}
+
+	/* Cases:
+	   Reading whole node and it's uncompressed - read directly to buffer provided, check CRC.
+	   Reading whole node and it's compressed - read into comprbuf, check CRC and decompress to buffer provided
+	   Reading partial node and it's uncompressed - read into readbuf, check CRC, and copy
+	   Reading partial node and it's compressed - read into readbuf, check checksum, decompress to decomprbuf and copy
+	*/
+	if (ri->compr == JFFS2_COMPR_NONE && len == je32_to_cpu(ri->dsize)) {
+		readbuf = buf;
+	} else {
+		readbuf = kmalloc(je32_to_cpu(ri->csize), GFP_KERNEL);
+		if (!readbuf) {
+			ret = -ENOMEM;
+			goto out_ri;
+		}
+	}
+	if (ri->compr != JFFS2_COMPR_NONE) {
+		if (len < je32_to_cpu(ri->dsize)) {
+			decomprbuf = kmalloc(je32_to_cpu(ri->dsize), GFP_KERNEL);
+			if (!decomprbuf) {
+				ret = -ENOMEM;
+				goto out_readbuf;
+			}
+		} else {
+			decomprbuf = buf;
+		}
+	} else {
+		decomprbuf = readbuf;
+	}
+
+	jffs2_dbg(2, "Read %d bytes to %p\n", je32_to_cpu(ri->csize),
+		  readbuf);
+	ret = jffs2_flash_read(c, (ref_offset(fd->raw)) + sizeof(*ri),
+			       je32_to_cpu(ri->csize), &readlen, readbuf);
+
+	if (!ret && readlen != je32_to_cpu(ri->csize))
+		ret = -EIO;
+	if (ret)
+		goto out_decomprbuf;
+
+	crc = crc32(0, readbuf, je32_to_cpu(ri->csize));
+	if (crc != je32_to_cpu(ri->data_crc)) {
+		pr_warn("Data CRC %08x != calculated CRC %08x for node at %08x\n",
+			je32_to_cpu(ri->data_crc), crc, ref_offset(fd->raw));
+		ret = -EIO;
+		goto out_decomprbuf;
+	}
+	jffs2_dbg(2, "Data CRC matches calculated CRC %08x\n", crc);
+	if (ri->compr != JFFS2_COMPR_NONE) {
+		jffs2_dbg(2, "Decompress %d bytes from %p to %d bytes at %p\n",
+			  je32_to_cpu(ri->csize), readbuf,
+			  je32_to_cpu(ri->dsize), decomprbuf);
+		ret = jffs2_decompress(c, f, ri->compr | (ri->usercompr << 8), readbuf, decomprbuf, je32_to_cpu(ri->csize), je32_to_cpu(ri->dsize));
+		if (ret) {
+			pr_warn("Error: jffs2_decompress returned %d\n", ret);
+			goto out_decomprbuf;
+		}
+	}
+
+	if (len < je32_to_cpu(ri->dsize)) {
+		memcpy(buf, decomprbuf+ofs, len);
+	}
+ out_decomprbuf:
+	if(decomprbuf != buf && decomprbuf != readbuf)
+		kfree(decomprbuf);
+ out_readbuf:
+	if(readbuf != buf)
+		kfree(readbuf);
+ out_ri:
+	jffs2_free_raw_inode(ri);
+
+	return ret;
+}
+
+int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
+			   unsigned char *buf, uint32_t offset, uint32_t len)
+{
+	uint32_t end = offset + len;
+	struct jffs2_node_frag *frag;
+	int ret;
+
+	jffs2_dbg(1, "%s(): ino #%u, range 0x%08x-0x%08x\n",
+		  __func__, f->inocache->ino, offset, offset + len);
+
+	frag = jffs2_lookup_node_frag(&f->fragtree, offset);
+
+	/* XXX FIXME: Where a single physical node actually shows up in two
+	   frags, we read it twice. Don't do that. */
+	/* Now we're pointing at the first frag which overlaps our page
+	 * (or perhaps is before it, if we've been asked to read off the
+	 * end of the file). */
+	while(offset < end) {
+		jffs2_dbg(2, "%s(): offset %d, end %d\n",
+			  __func__, offset, end);
+		if (unlikely(!frag || frag->ofs > offset ||
+			     frag->ofs + frag->size <= offset)) {
+			uint32_t holesize = end - offset;
+			if (frag && frag->ofs > offset) {
+				jffs2_dbg(1, "Eep. Hole in ino #%u fraglist. frag->ofs = 0x%08x, offset = 0x%08x\n",
+					  f->inocache->ino, frag->ofs, offset);
+				holesize = min(holesize, frag->ofs - offset);
+			}
+			jffs2_dbg(1, "Filling non-frag hole from %d-%d\n",
+				  offset, offset + holesize);
+			memset(buf, 0, holesize);
+			buf += holesize;
+			offset += holesize;
+			continue;
+		} else if (unlikely(!frag->node)) {
+			uint32_t holeend = min(end, frag->ofs + frag->size);
+			jffs2_dbg(1, "Filling frag hole from %d-%d (frag 0x%x 0x%x)\n",
+				  offset, holeend, frag->ofs,
+				  frag->ofs + frag->size);
+			memset(buf, 0, holeend - offset);
+			buf += holeend - offset;
+			offset = holeend;
+			frag = frag_next(frag);
+			continue;
+		} else {
+			uint32_t readlen;
+			uint32_t fragofs; /* offset within the frag to start reading */
+
+			fragofs = offset - frag->ofs;
+			readlen = min(frag->size - fragofs, end - offset);
+			jffs2_dbg(1, "Reading %d-%d from node at 0x%08x (%d)\n",
+				  frag->ofs+fragofs,
+				  frag->ofs + fragofs+readlen,
+				  ref_offset(frag->node->raw),
+				  ref_flags(frag->node->raw));
+			ret = jffs2_read_dnode(c, f, frag->node, buf, fragofs + frag->ofs - frag->node->ofs, readlen);
+			jffs2_dbg(2, "node read done\n");
+			if (ret) {
+				jffs2_dbg(1, "%s(): error %d\n",
+					  __func__, ret);
+				memset(buf, 0, readlen);
+				return ret;
+			}
+			buf += readlen;
+			offset += readlen;
+			frag = frag_next(frag);
+			jffs2_dbg(2, "node read was OK. Looping\n");
+		}
+	}
+	return 0;
+}
+