NOR Flash and other non-writebuffered devices write directly through jffs2_flash_direct_writev() and jffs2_flash_direct_write() without any write-back verification. If mtd_write() succeeds but the readable medium differs from JFFS2's source buffer, a later node CRC failure cannot distinguish transport/program-time corruption from post-commit media damage.
Move jffs2_verify_write() from wbuf.c to writev.c so it can be shared by both writebuffered and direct write paths. Add jffs2_verify_writev() to iterate over kvec entries and verify each one individually. In both direct write functions, add mtd_write() return value and retlen checks, and invoke verification after a successful complete write. In jffs2_flash_direct_writev(), move the mtd_writev() call before jffs2_sum_add_kvec() so that *retlen is always set by the MTD layer first. The original ordering let jffs2_sum_add_kvec() return early on error without ever touching *retlen, leaving the caller's retlen check to read an uninitialized value. Keep the same order in jffs2_flash_direct_write(). Signed-off-by: zhouminqiang <[email protected]> --- fs/jffs2/os-linux.h | 11 ++++ fs/jffs2/wbuf.c | 70 ------------------------- fs/jffs2/writev.c | 121 +++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 131 insertions(+), 71 deletions(-) diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h index 86ab014a349c..e73ef643fd97 100644 --- a/fs/jffs2/os-linux.h +++ b/fs/jffs2/os-linux.h @@ -192,6 +192,17 @@ int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs, int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *retlen, const u_char *buf); +#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY +int jffs2_verify_write(struct jffs2_sb_info *c, const unsigned char *buf, + uint32_t ofs, size_t len); +int jffs2_verify_writev(struct jffs2_sb_info *c, + const struct kvec *vecs, + unsigned long count, loff_t to); +#else +#define jffs2_verify_write(c, b, o, l) (0) +#define jffs2_verify_writev(c, v, cnt, t) (0) +#endif + #endif /* __JFFS2_OS_LINUX_H__ */ diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c index 81f3538ca258..2f4937951a0c 100644 --- a/fs/jffs2/wbuf.c +++ b/fs/jffs2/wbuf.c @@ -226,76 +226,6 @@ static struct jffs2_raw_node_ref **jffs2_incore_replace_raw(struct jffs2_sb_info return NULL; } -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY -static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf, - uint32_t ofs, size_t len) -{ - int ret; - size_t retlen, i; - char *eccstr; - void *verify_buf; - - 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, 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 != 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, len)) { - ret = 0; - goto out_free; - } - - for (i = 0; i < len; i++) { - uint8_t c1 = ((uint8_t *)buf)[i]; - uint8_t c2 = ((uint8_t *)verify_buf)[i]; - int dump_len; - - if (c1 == c2) - continue; - - if (ret == -EUCLEAN) - eccstr = "corrected"; - else if (ret == -EBADMSG) - eccstr = "correction failed"; - else - eccstr = "OK or unused"; - - 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); - - pr_warn("Read back:\n"); - print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, - verify_buf + i, dump_len, 0); - - ret = -EIO; - goto out_free; - } - -out_free: - kfree(verify_buf); - return ret; -} -#else -#define jffs2_verify_write(c,b,o,l) (0) -#endif - /* Recover from failure to write wbuf. Recover the nodes up to the * wbuf, not the one which we were starting to try to write. */ diff --git a/fs/jffs2/writev.c b/fs/jffs2/writev.c index a1bda9dab3f8..2cb8cb030ae3 100644 --- a/fs/jffs2/writev.c +++ b/fs/jffs2/writev.c @@ -10,12 +10,121 @@ */ #include <linux/kernel.h> +#include <linux/slab.h> #include <linux/mtd/mtd.h> #include "nodelist.h" +#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY +int jffs2_verify_write(struct jffs2_sb_info *c, const unsigned char *buf, + uint32_t ofs, size_t len) +{ + int ret; + size_t retlen, i; + char *eccstr; + void *verify_buf; + + 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, 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 != 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, len)) { + ret = 0; + goto out_free; + } + + for (i = 0; i < len; i++) { + uint8_t c1 = ((uint8_t *)buf)[i]; + uint8_t c2 = ((uint8_t *)verify_buf)[i]; + int dump_len; + + if (c1 == c2) + continue; + + if (ret == -EUCLEAN) + eccstr = "corrected"; + else if (ret == -EBADMSG) + eccstr = "correction failed"; + else + eccstr = "OK or unused"; + + 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); + + pr_warn("Read back:\n"); + print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, + verify_buf + i, dump_len, 0); + + ret = -EIO; + goto out_free; + } + +out_free: + kfree(verify_buf); + return ret; +} + +int jffs2_verify_writev(struct jffs2_sb_info *c, + const struct kvec *vecs, + unsigned long count, loff_t to) +{ + loff_t ofs = to; + unsigned long i; + int ret; + + for (i = 0; i < count; i++) { + if (!vecs[i].iov_len) + continue; + ret = jffs2_verify_write(c, vecs[i].iov_base, ofs, + vecs[i].iov_len); + if (ret) + return ret; + ofs += vecs[i].iov_len; + } + return 0; +} +#endif /* CONFIG_JFFS2_FS_WBUF_VERIFY */ + int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen) { + int ret; + + ret = mtd_writev(c->mtd, vecs, count, to, retlen); + + if (ret) { + pr_warn("%s(): Write failed with %d\n", __func__, ret); + } else { + size_t totlen = 0; + unsigned long i; + + for (i = 0; i < count; i++) + totlen += vecs[i].iov_len; + if (*retlen != totlen) { + pr_warn("%s(): Write was short: %zu instead of %zu\n", + __func__, *retlen, totlen); + ret = -EIO; + } else + ret = jffs2_verify_writev(c, vecs, count, to); + } + if (!jffs2_is_writebuffered(c)) { if (jffs2_sum_active()) { int res; @@ -26,15 +135,25 @@ int jffs2_flash_direct_writev(struct jffs2_sb_info *c, const struct kvec *vecs, } } - return mtd_writev(c->mtd, vecs, count, to, retlen); + return ret; } int jffs2_flash_direct_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *retlen, const u_char *buf) { int ret; + ret = mtd_write(c->mtd, ofs, len, retlen, buf); + if (ret) { + pr_warn("%s(): Write failed with %d\n", __func__, ret); + } else if (*retlen != len) { + pr_warn("%s(): Write was short: %zu instead of %zu\n", + __func__, *retlen, len); + ret = -EIO; + } else + ret = jffs2_verify_write(c, buf, ofs, len); + if (jffs2_sum_active()) { struct kvec vecs[1]; int res; -- 2.52.0
