jffs2_flash_writev() performs writes in three phases: phase 1 fills
the write buffer and flushes it when full, phase 2 writes full pages
directly via mtd_write() bypassing the buffer, and phase 3 fills the
remaining data into the write buffer.

Phases 1 and 3 both invoke __jffs2_flush_wbuf() when the buffer is
full, which includes write-back verification when
CONFIG_JFFS2_FS_WBUF_VERIFY is enabled. However phase 2, which
handles the bulk of the write data, calls mtd_write() directly
without any verification.

Phase 2 direct writes may span multiple wbuf_pagesize pages. Extend
jffs2_verify_write() with a len parameter to specify the data length
to verify, and add the verification call after the phase 2
mtd_write() to cover this gap.

Signed-off-by: zhouminqiang <[email protected]>
---
 fs/jffs2/wbuf.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 74e169dedab7..81f3538ca258 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -228,38 +228,38 @@ static struct jffs2_raw_node_ref 
**jffs2_incore_replace_raw(struct jffs2_sb_info
 
 #ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
 static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf,
-                             uint32_t ofs)
+                             uint32_t ofs, size_t len)
 {
        int ret;
        size_t retlen, i;
        char *eccstr;
        void *verify_buf;
 
-       verify_buf = kmalloc(c->wbuf_pagesize, GFP_NOFS);
+       verify_buf = kmalloc(len, GFP_NOFS);
        if (!verify_buf) {
                pr_warn("%s(): verify buffer allocation failed, skipping 
verification\n",
                        __func__);
                return 0;
        }
 
-       ret = mtd_read(c->mtd, ofs, c->wbuf_pagesize, &retlen, verify_buf);
+       ret = mtd_read(c->mtd, ofs, len, &retlen, verify_buf);
 
        if (ret && ret != -EUCLEAN && ret != -EBADMSG) {
                pr_warn("%s(): Read back of page at %08x failed: %d\n",
                        __func__, ofs, ret);
                goto out_free;
-       } else if (retlen != c->wbuf_pagesize) {
-               pr_warn("%s(): Read back of page at %08x gave short read: %zu 
not %d\n",
-                       __func__, ofs, retlen, c->wbuf_pagesize);
+       } else if (retlen != len) {
+               pr_warn("%s(): Read back of page at %08x gave short read: %zu 
not %zu\n",
+                       __func__, ofs, retlen, len);
                ret = -EIO;
                goto out_free;
        }
-       if (!memcmp(buf, verify_buf, c->wbuf_pagesize)) {
+       if (!memcmp(buf, verify_buf, len)) {
                ret = 0;
                goto out_free;
        }
 
-       for (i = 0; i < c->wbuf_pagesize; i++) {
+       for (i = 0; i < len; i++) {
                uint8_t c1 = ((uint8_t *)buf)[i];
                uint8_t c2 = ((uint8_t *)verify_buf)[i];
                int dump_len;
@@ -274,9 +274,9 @@ static int jffs2_verify_write(struct jffs2_sb_info *c, 
unsigned char *buf,
                else
                        eccstr = "OK or unused";
 
-               dump_len = min_t(int, 128, c->wbuf_pagesize - i);
-               pr_warn("Write verify error (ECC %s) at %08x (+%zu/%d). 
Wrote:\n",
-                       eccstr, ofs, i, c->wbuf_pagesize);
+               dump_len = min_t(int, 128, len - i);
+               pr_warn("Write verify error (ECC %s) at %08x (+%zu/%zu). 
Wrote:\n",
+                       eccstr, ofs, i, len);
                print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
                               buf + i, dump_len, 0);
 
@@ -293,7 +293,7 @@ static int jffs2_verify_write(struct jffs2_sb_info *c, 
unsigned char *buf,
        return ret;
 }
 #else
-#define jffs2_verify_write(c,b,o) (0)
+#define jffs2_verify_write(c,b,o,l) (0)
 #endif
 
 /* Recover from failure to write wbuf. Recover the nodes up to the
@@ -458,7 +458,7 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
                        ret = mtd_write(c->mtd, ofs, towrite, &retlen,
                                        rewrite_buf);
 
-               if (ret || retlen != towrite || jffs2_verify_write(c, 
rewrite_buf, ofs)) {
+               if (ret || retlen != towrite || jffs2_verify_write(c, 
rewrite_buf, ofs, towrite)) {
                        /* Argh. We tried. Really we did. */
                        pr_crit("Recovery of wbuf failed due to a second write 
error. Data loss ensues.\n");
                        kfree(buf);
@@ -676,7 +676,10 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int 
pad)
                        retlen, c->wbuf_pagesize);
                ret = -EIO;
                goto wfail;
-       } else if ((ret = jffs2_verify_write(c, c->wbuf, c->wbuf_ofs))) {
+       }
+
+       ret = jffs2_verify_write(c, c->wbuf, c->wbuf_ofs, c->wbuf_pagesize);
+       if (ret) {
        wfail:
                jffs2_wbuf_recover(c);
 
@@ -908,6 +911,10 @@ int jffs2_flash_writev(struct jffs2_sb_info *c, const 
struct kvec *invecs,
                        if (ret < 0 || wbuf_retlen != PAGE_DIV(vlen))
                                goto outfile;
 
+                       ret = jffs2_verify_write(c, v, outvec_to, 
PAGE_DIV(vlen));
+                       if (ret)
+                               goto outfile;
+
                        vlen -= wbuf_retlen;
                        outvec_to += wbuf_retlen;
                        c->wbuf_ofs = outvec_to;
-- 
2.52.0


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