[LU-18987] Strange LASSERT in mdt_dom_read_on_open()

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.17.0
• Affects Version/s: Lustre 2.17.0
• Severity: 3
• Assignee: Oleg Drokin
• Reporter: Oleg Drokin

Description

There's a strange code in mdt_dom_read_on_open (highlighted by smatch) that asserts for some non-sensical stuff that's not even changed inside the loop:

        rc = dt_read_prep(env, mo, lnb, nr_local);
        if (unlikely(rc))
                GOTO(buf_put, rc);
        /* copy data to the buffer finally */
        for (i = 0; i < nr_local; i++) {
                char *p = kmap(lnb[i].lnb_page);
                long off;                LASSERT(lnb[i].lnb_page_offset == 0);
                off = lnb[i].lnb_len & ~PAGE_MASK;
                if (off > 0)
                        memset(p + off, 0, PAGE_SIZE - off);
                memcpy(buf + (i << PAGE_SHIFT), p, lnb[i].lnb_len);
                kunmap(lnb[i].lnb_page);
                copied += lnb[i].lnb_len;
====>>>         LASSERT(rc <= len);        <<<<======= here
        }

I checked with Mike (original path author) and he thinks we can just safely drop it.

Issue Links

• is related to: LU-10181 DoM performance optimization

Comments

[Peter Jones]

Merged for 2.17

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/59173/
Subject: LU-18987 mdt: Remove stray assertion for dom read
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 130792644e0d8047c60896df71f942f445dc3c37

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/59173
Subject: LU-18987 mdt: Remove stray assertion for dom read
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 0aaf7ab39823a07d6609af0b0e45c9d1c9b6daef