diff options
| author | Jan Kara <jack@suse.cz> | 2022-12-07 12:27:05 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2022-12-08 21:49:25 -0500 |
| commit | dff4ac75eeeefc4397fe7cf8ce559425bf46b1f7 (patch) | |
| tree | 89aa03b1966de1a8dcb907b1e76ebca61e897d50 /fs/ext4/page-io.c | |
| parent | 04e568a3b31cfbd545c04c8bfc35c20e5ccfce0f (diff) | |
ext4: move keep_towrite handling to ext4_bio_write_page()
When we are writing back page but we cannot for some reason write all
its buffers (e.g. because we cannot allocate blocks in current context) we
have to keep TOWRITE tag set in the mapping as otherwise racing
WB_SYNC_ALL writeback that could write these buffers can skip the page
and result in data loss. We will need this logic for writeback during
transaction commit so move the logic from ext4_writepage() to
ext4_bio_write_page().
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20221207112722.22220-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/page-io.c')
| -rw-r--r-- | fs/ext4/page-io.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 4e68ace86f11..4f9ecacd10aa 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -430,8 +430,7 @@ submit_and_retry: int ext4_bio_write_page(struct ext4_io_submit *io, struct page *page, - int len, - bool keep_towrite) + int len) { struct page *bounce_page = NULL; struct inode *inode = page->mapping->host; @@ -441,14 +440,11 @@ int ext4_bio_write_page(struct ext4_io_submit *io, int nr_submitted = 0; int nr_to_submit = 0; struct writeback_control *wbc = io->io_wbc; + bool keep_towrite = false; BUG_ON(!PageLocked(page)); BUG_ON(PageWriteback(page)); - if (keep_towrite) - set_page_writeback_keepwrite(page); - else - set_page_writeback(page); ClearPageError(page); /* @@ -483,12 +479,17 @@ int ext4_bio_write_page(struct ext4_io_submit *io, if (!buffer_mapped(bh)) clear_buffer_dirty(bh); /* - * Keeping dirty some buffer we cannot write? Make - * sure to redirty the page. This happens e.g. when - * doing writeout for transaction commit. + * Keeping dirty some buffer we cannot write? Make sure + * to redirty the page and keep TOWRITE tag so that + * racing WB_SYNC_ALL writeback does not skip the page. + * This happens e.g. when doing writeout for + * transaction commit. */ - if (buffer_dirty(bh) && !PageDirty(page)) - redirty_page_for_writepage(wbc, page); + if (buffer_dirty(bh)) { + if (!PageDirty(page)) + redirty_page_for_writepage(wbc, page); + keep_towrite = true; + } if (io->io_bio) ext4_io_submit(io); continue; @@ -500,6 +501,10 @@ int ext4_bio_write_page(struct ext4_io_submit *io, nr_to_submit++; } while ((bh = bh->b_this_page) != head); + /* Nothing to submit? Just unlock the page... */ + if (!nr_to_submit) + goto unlock; + bh = head = page_buffers(page); /* @@ -550,6 +555,11 @@ int ext4_bio_write_page(struct ext4_io_submit *io, } } + if (keep_towrite) + set_page_writeback_keepwrite(page); + else + set_page_writeback(page); + /* Now submit buffers to write */ do { if (!buffer_async_write(bh)) @@ -558,11 +568,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io, bounce_page ? bounce_page : page, bh); nr_submitted++; } while ((bh = bh->b_this_page) != head); - unlock: unlock_page(page); - /* Nothing submitted - we have to end page writeback */ - if (!nr_submitted) - end_page_writeback(page); return ret; } |