diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/nvmutil/nvmutil.c | 39 |
1 files changed, 20 insertions, 19 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 59d2facd..120586a9 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -2073,25 +2073,8 @@ real_pread_pwrite: * if the offset changed to what * we previously got. If it did, * then another thread may have - * changed it. - * - * This is no substitute for real - * pread/pwrite, which would be - * fully atomic at kernel-level - * and do not use file offsets. - * - * TODO: Add a toggle to make it - * recover instead, reset - * to known offset, and - * carry on operations. - * - * Failure is the better option - * here, since recovery would - * mask hidden bugs in code. - * We cannot guarantee thread - * safety, except in the event - * that violations cause exit; - * you would then debug it. + * changed it. Enabled if + * off_reset is OFF_RESET. */ if (off != verified) { if (!off_reset) @@ -2112,6 +2095,24 @@ real_pread_pwrite: return -1; } + verified = lseek_loop(fd, (off_t)0, SEEK_CUR, + loop_eagain, loop_eintr); + + /* + * Verify again before I/O + * (even with OFF_ERR) + * + * This implements the first check + * even with OFF_ERR, but without + * the recovery. On ERR_RESET, if + * the check fails again, then we + * know something else is touching + * the file, so it's best that we + * probably leave it alone and err. + */ + if (verified != off) + goto err_prw; + do { if (rw_type == IO_PREAD) r = read(fd, mem, nrw); |