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UBIFS: Add log overlap assertions

PATCH Superseded hujianyang 1 participant 2 messages Jul 29, 2014 – Jul 30, 2014

Subsystems (2)
Memory technology devices (MTD) UBI file system (UBIFS)
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hujianyang

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#0 lore raw

PATCH 1/1 UBIFS: Add log overlap assertions

We use a circle area to record log node in ubifs. This log area should not be overlapped. But after researching the code, I found some condition may lead log head wrap log ltail. Although we've fixed the problems discovered, there may be some other issues still left.

This patch adds assertions when lhead changes to next leb to make sure ltail is not wrapped.

Signed-off-by hujianyang <[email protected]>
---
 fs/ubifs/log.c | 2 ++
 1 file changed, 2 insertions(+)
fs/ubifs/log.c +2 -0
index 7e818ec..c14628f 100644
@@ -244,6 +244,7 @@ int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
 
        if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
                c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+               ubifs_assert(c->lhead_lnum != c->ltail_lnum);
                c->lhead_offs = 0;
        }
 

@@ -408,6 +409,7 @@ int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
        /* Switch to the next log LEB */
        if (c->lhead_offs) {
                c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+               ubifs_assert(c->lhead_lnum != c->ltail_lnum);
                c->lhead_offs = 0;
        }
Signature · 1 line
1.8.1.4
author
#1 lore raw
Quoted 28 lines · hujianyang

We use a circle area to record log node in ubifs. This log area should not be overlapped. But after researching the code, I found some condition may lead log head wrap log ltail. Although we've fixed the problems discovered, there may be some other issues still left.

This patch adds assertions when lhead changes to next leb to make sure ltail is not wrapped.

Signed-off-by hujianyang <[email protected]>
---
 fs/ubifs/log.c | 2 ++
 1 file changed, 2 insertions(+)
fs/ubifs/log.c +1 -0
index 7e818ec..c14628f 100644
@@ -244,6 +244,7 @@ int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
 
        if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
                c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+               ubifs_assert(c->lhead_lnum != c->ltail_lnum);
                c->lhead_offs = 0;
        }

fs/ubifs/log.c int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum) · line 415

Quoted 7 lines
fs/ubifs/log.c +1 -0
@@ -408,6 +409,7 @@ int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
        /* Switch to the next log LEB */
        if (c->lhead_offs) {
                c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
+               ubifs_assert(c->lhead_lnum != c->ltail_lnum);
                c->lhead_offs = 0;
        }

Forgive me. This patch is not created in right format.

Please drop it and I will resend a new one.