From: Mikhail Pershin <mike.pers...@intel.com> - llh_cat_idx may become bigger than llog bitmap size in llog_cat_set_first_idx() function - it is wrong to use previous cur_offset as new buffer offset, new offset should be calculated from value returned by llog_next_block(). - optimize llog_skip_over() to find llog entry offset by index for llog with fixed-size records.
Signed-off-by: Mikhail Pershin <mike.pers...@intel.com> Signed-off-by: Bob Glossman <bob.gloss...@intel.com> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6714 Reviewed-on: http://review.whamcloud.com/15316 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6163 Reviewed-on: http://review.whamcloud.com/18819 Reviewed-by: John L. Hammond <john.hamm...@intel.com> Reviewed-by: James Simmons <uja.o...@yahoo.com> Reviewed-by: Oleg Drokin <oleg.dro...@intel.com> Signed-off-by: James Simmons <jsimm...@infradead.org> --- ChangeLog: v1) Initial patch with umoddi issue v2) Included fix from patch LU-6163 that fixed umoddi problem v3) Remove no longer needed last_offset variable drivers/staging/lustre/lustre/obdclass/llog.c | 82 +++++++++++++++++------- include/linux/fs.h | 2 +- 2 files changed, 59 insertions(+), 25 deletions(-) diff --git a/drivers/staging/lustre/lustre/obdclass/llog.c b/drivers/staging/lustre/lustre/obdclass/llog.c index 3bc1789..ae63047 100644 --- a/drivers/staging/lustre/lustre/obdclass/llog.c +++ b/drivers/staging/lustre/lustre/obdclass/llog.c @@ -217,8 +217,7 @@ static int llog_process_thread(void *arg) struct llog_log_hdr *llh = loghandle->lgh_hdr; struct llog_process_cat_data *cd = lpi->lpi_catdata; char *buf; - __u64 cur_offset; - __u64 last_offset; + u64 cur_offset, tmp_offset; int chunk_size; int rc = 0, index = 1, last_index; int saved_index = 0; @@ -229,6 +228,8 @@ static int llog_process_thread(void *arg) cur_offset = llh->llh_hdr.lrh_len; chunk_size = llh->llh_hdr.lrh_len; + /* expect chunk_size to be power of two */ + LASSERT(is_power_of_2(chunk_size)); buf = libcfs_kvzalloc(chunk_size, GFP_NOFS); if (!buf) { @@ -245,38 +246,50 @@ static int llog_process_thread(void *arg) else last_index = LLOG_HDR_BITMAP_SIZE(llh) - 1; - /* Record is not in this buffer. */ - if (index > last_index) - goto out; - while (rc == 0) { + unsigned int buf_offset = 0; struct llog_rec_hdr *rec; + bool partial_chunk; + off_t chunk_offset; /* skip records not set in bitmap */ while (index <= last_index && !ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) ++index; - LASSERT(index <= last_index + 1); - if (index == last_index + 1) + if (index > last_index) break; -repeat: + CDEBUG(D_OTHER, "index: %d last_index %d\n", index, last_index); - +repeat: /* get the buf with our target record; avoid old garbage */ memset(buf, 0, chunk_size); - last_offset = cur_offset; rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index, index, &cur_offset, buf, chunk_size); if (rc) goto out; + /* + * NB: after llog_next_block() call the cur_offset is the + * offset of the next block after read one. + * The absolute offset of the current chunk is calculated + * from cur_offset value and stored in chunk_offset variable. + */ + tmp_offset = cur_offset; + if (do_div(tmp_offset, chunk_size)) { + partial_chunk = true; + chunk_offset = cur_offset & ~(chunk_size - 1); + } else { + partial_chunk = false; + chunk_offset = cur_offset - chunk_size; + } + /* NB: when rec->lrh_len is accessed it is already swabbed * since it is used at the "end" of the loop and the rec * swabbing is done at the beginning of the loop. */ - for (rec = (struct llog_rec_hdr *)buf; + for (rec = (struct llog_rec_hdr *)(buf + buf_offset); (char *)rec < buf + chunk_size; rec = llog_rec_hdr_next(rec)) { CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n", @@ -288,13 +301,28 @@ static int llog_process_thread(void *arg) CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n", rec->lrh_type, rec->lrh_index); - if (rec->lrh_index == 0) { - /* probably another rec just got added? */ - rc = 0; - if (index <= loghandle->lgh_last_idx) - goto repeat; - goto out; /* no more records */ + /* + * for partial chunk the end of it is zeroed, check + * for index 0 to distinguish it. + */ + if (partial_chunk && !rec->lrh_index) { + /* concurrent llog_add() might add new records + * while llog_processing, check this is not + * the case and re-read the current chunk + * otherwise. + */ + if (index > loghandle->lgh_last_idx) { + rc = 0; + goto out; + } + CDEBUG(D_OTHER, "Re-read last llog buffer for new records, index %u, last %u\n", + index, loghandle->lgh_last_idx); + /* save offset inside buffer for the re-read */ + buf_offset = (char *)rec - (char *)buf; + cur_offset = chunk_offset; + goto repeat; } + if (!rec->lrh_len || rec->lrh_len > chunk_size) { CWARN("invalid length %d in llog record for index %d/%d\n", rec->lrh_len, @@ -309,6 +337,14 @@ static int llog_process_thread(void *arg) continue; } + if (rec->lrh_index != index) { + CERROR("%s: Invalid record: index %u but expected %u\n", + loghandle->lgh_ctxt->loc_obd->obd_name, + rec->lrh_index, index); + rc = -ERANGE; + goto out; + } + CDEBUG(D_OTHER, "lrh_index: %d lrh_len: %d (%d remains)\n", rec->lrh_index, rec->lrh_len, @@ -316,7 +352,7 @@ static int llog_process_thread(void *arg) loghandle->lgh_cur_idx = rec->lrh_index; loghandle->lgh_cur_offset = (char *)rec - (char *)buf + - last_offset; + chunk_offset; /* if set, process the callback on this record */ if (ext2_test_bit(index, LLOG_HDR_BITMAP(llh))) { @@ -325,16 +361,14 @@ static int llog_process_thread(void *arg) last_called_index = index; if (rc) goto out; - } else { - CDEBUG(D_OTHER, "Skipped index %d\n", index); } - /* next record, still in buffer? */ - ++index; - if (index > last_index) { + /* exit if the last index is reached */ + if (index >= last_index) { rc = 0; goto out; } + index++; } } diff --git a/include/linux/fs.h b/include/linux/fs.h index dc0478c..3f70ec3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2690,7 +2690,7 @@ enum kernel_read_file_id { static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) { - if (id < 0 || id >= READING_MAX_ID) + if (id >= READING_MAX_ID) return kernel_read_file_str[READING_UNKNOWN]; return kernel_read_file_str[id]; -- 1.7.1
