| Message ID | 20220831072111.3569680-7-yi.zhang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | buffer: remove ll_rw_block() | expand |
On Wed 31-08-22 15:21:03, Zhang Yi wrote: > ll_rw_block() is not safe for the sync read path because it cannot > guarantee that submitting read IO if the buffer has been locked. We > could get false positive EIO after wait_on_buffer() if the buffer has > been locked by others. So stop using ll_rw_block() in > journal_get_superblock(). We also switch to new bh_readahead_batch() > for the buffer array readahead path. > > Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/jbd2/journal.c | 7 +++---- > fs/jbd2/recovery.c | 16 ++++++++++------ > 2 files changed, 13 insertions(+), 10 deletions(-) > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 6350d3857c89..5a903aae6aad 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -1893,15 +1893,14 @@ static int journal_get_superblock(journal_t *journal) > { > struct buffer_head *bh; > journal_superblock_t *sb; > - int err = -EIO; > + int err; > > bh = journal->j_sb_buffer; > > J_ASSERT(bh != NULL); > if (!buffer_uptodate(bh)) { > - ll_rw_block(REQ_OP_READ, 1, &bh); > - wait_on_buffer(bh); > - if (!buffer_uptodate(bh)) { > + err = bh_read(bh, 0); > + if (err) { > printk(KERN_ERR > "JBD2: IO error reading journal superblock\n"); > goto out; > diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c > index f548479615c6..ee56a30b71cf 100644 > --- a/fs/jbd2/recovery.c > +++ b/fs/jbd2/recovery.c > @@ -100,7 +100,7 @@ static int do_readahead(journal_t *journal, unsigned int start) > if (!buffer_uptodate(bh) && !buffer_locked(bh)) { > bufs[nbufs++] = bh; > if (nbufs == MAXBUF) { > - ll_rw_block(REQ_OP_READ, nbufs, bufs); > + bh_readahead_batch(bufs, nbufs, 0); > journal_brelse_array(bufs, nbufs); > nbufs = 0; > } > @@ -109,7 +109,7 @@ static int do_readahead(journal_t *journal, unsigned int start) > } > > if (nbufs) > - ll_rw_block(REQ_OP_READ, nbufs, bufs); > + bh_readahead_batch(bufs, nbufs, 0); > err = 0; > > failed: > @@ -152,9 +152,14 @@ static int jread(struct buffer_head **bhp, journal_t *journal, > return -ENOMEM; > > if (!buffer_uptodate(bh)) { > - /* If this is a brand new buffer, start readahead. > - Otherwise, we assume we are already reading it. */ > - if (!buffer_req(bh)) > + /* > + * If this is a brand new buffer, start readahead. > + * Otherwise, we assume we are already reading it. > + */ > + bool need_readahead = !buffer_req(bh); > + > + bh_read_nowait(bh, 0); > + if (need_readahead) > do_readahead(journal, offset); > wait_on_buffer(bh); > } > @@ -687,7 +692,6 @@ static int do_one_pass(journal_t *journal, > mark_buffer_dirty(nbh); > BUFFER_TRACE(nbh, "marking uptodate"); > ++info->nr_replays; > - /* ll_rw_block(WRITE, 1, &nbh); */ > unlock_buffer(nbh); > brelse(obh); > brelse(nbh); > -- > 2.31.1 >
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 6350d3857c89..5a903aae6aad 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1893,15 +1893,14 @@ static int journal_get_superblock(journal_t *journal) { struct buffer_head *bh; journal_superblock_t *sb; - int err = -EIO; + int err; bh = journal->j_sb_buffer; J_ASSERT(bh != NULL); if (!buffer_uptodate(bh)) { - ll_rw_block(REQ_OP_READ, 1, &bh); - wait_on_buffer(bh); - if (!buffer_uptodate(bh)) { + err = bh_read(bh, 0); + if (err) { printk(KERN_ERR "JBD2: IO error reading journal superblock\n"); goto out; diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index f548479615c6..ee56a30b71cf 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -100,7 +100,7 @@ static int do_readahead(journal_t *journal, unsigned int start) if (!buffer_uptodate(bh) && !buffer_locked(bh)) { bufs[nbufs++] = bh; if (nbufs == MAXBUF) { - ll_rw_block(REQ_OP_READ, nbufs, bufs); + bh_readahead_batch(bufs, nbufs, 0); journal_brelse_array(bufs, nbufs); nbufs = 0; } @@ -109,7 +109,7 @@ static int do_readahead(journal_t *journal, unsigned int start) } if (nbufs) - ll_rw_block(REQ_OP_READ, nbufs, bufs); + bh_readahead_batch(bufs, nbufs, 0); err = 0; failed: @@ -152,9 +152,14 @@ static int jread(struct buffer_head **bhp, journal_t *journal, return -ENOMEM; if (!buffer_uptodate(bh)) { - /* If this is a brand new buffer, start readahead. - Otherwise, we assume we are already reading it. */ - if (!buffer_req(bh)) + /* + * If this is a brand new buffer, start readahead. + * Otherwise, we assume we are already reading it. + */ + bool need_readahead = !buffer_req(bh); + + bh_read_nowait(bh, 0); + if (need_readahead) do_readahead(journal, offset); wait_on_buffer(bh); } @@ -687,7 +692,6 @@ static int do_one_pass(journal_t *journal, mark_buffer_dirty(nbh); BUFFER_TRACE(nbh, "marking uptodate"); ++info->nr_replays; - /* ll_rw_block(WRITE, 1, &nbh); */ unlock_buffer(nbh); brelse(obh); brelse(nbh);
ll_rw_block() is not safe for the sync read path because it cannot guarantee that submitting read IO if the buffer has been locked. We could get false positive EIO after wait_on_buffer() if the buffer has been locked by others. So stop using ll_rw_block() in journal_get_superblock(). We also switch to new bh_readahead_batch() for the buffer array readahead path. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> --- fs/jbd2/journal.c | 7 +++---- fs/jbd2/recovery.c | 16 ++++++++++------ 2 files changed, 13 insertions(+), 10 deletions(-)