| Message ID | 20240203071147.862076-6-hch@lst.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [01/13] writeback: remove a duplicate prototype for tag_pages_for_writeback | expand |
On Sat 03-02-24 08:11:39, Christoph Hellwig wrote: > Rework the way we deal with the cleanup after the writepage call. > > First handle the magic AOP_WRITEPAGE_ACTIVATE separately from real error > returns to get it out of the way of the actual error handling path. > > The split the handling on intgrity vs non-integrity branches first, > and return early using a goto for the non-ingegrity early loop condition > to remove the need for the done and done_index local variables, and for > assigning the error to ret when we can just return error directly. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > mm/page-writeback.c | 84 ++++++++++++++++++--------------------------- > 1 file changed, 33 insertions(+), 51 deletions(-) > > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index c7c494526bc650..88b2c4c111c01b 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -2396,13 +2396,12 @@ int write_cache_pages(struct address_space *mapping, > void *data) > { > int ret = 0; > - int done = 0; > int error; > struct folio_batch fbatch; > + struct folio *folio; > int nr_folios; > pgoff_t index; > pgoff_t end; /* Inclusive */ > - pgoff_t done_index; > xa_mark_t tag; > > folio_batch_init(&fbatch); > @@ -2419,8 +2418,7 @@ int write_cache_pages(struct address_space *mapping, > } else { > tag = PAGECACHE_TAG_DIRTY; > } > - done_index = index; > - while (!done && (index <= end)) { > + while (index <= end) { > int i; > > nr_folios = filemap_get_folios_tag(mapping, &index, end, > @@ -2430,11 +2428,7 @@ int write_cache_pages(struct address_space *mapping, > break; > > for (i = 0; i < nr_folios; i++) { > - struct folio *folio = fbatch.folios[i]; > - unsigned long nr; > - > - done_index = folio->index; > - > + folio = fbatch.folios[i]; > folio_lock(folio); > > /* > @@ -2469,45 +2463,32 @@ int write_cache_pages(struct address_space *mapping, > > trace_wbc_writepage(wbc, inode_to_bdi(mapping->host)); > error = writepage(folio, wbc, data); > - nr = folio_nr_pages(folio); > - wbc->nr_to_write -= nr; > - if (unlikely(error)) { > - /* > - * Handle errors according to the type of > - * writeback. There's no need to continue for > - * background writeback. Just push done_index > - * past this page so media errors won't choke > - * writeout for the entire file. For integrity > - * writeback, we must process the entire dirty > - * set regardless of errors because the fs may > - * still have state to clear for each page. In > - * that case we continue processing and return > - * the first error. > - */ > - if (error == AOP_WRITEPAGE_ACTIVATE) { > - folio_unlock(folio); > - error = 0; > - } else if (wbc->sync_mode != WB_SYNC_ALL) { > - ret = error; > - done_index = folio->index + nr; > - done = 1; > - break; > - } > - if (!ret) > - ret = error; > + wbc->nr_to_write -= folio_nr_pages(folio); > + > + if (error == AOP_WRITEPAGE_ACTIVATE) { > + folio_unlock(folio); > + error = 0; > } > > /* > - * We stop writing back only if we are not doing > - * integrity sync. In case of integrity sync we have to > - * keep going until we have written all the pages > - * we tagged for writeback prior to entering this loop. > + * For integrity writeback we have to keep going until > + * we have written all the folios we tagged for > + * writeback above, even if we run past wbc->nr_to_write > + * or encounter errors. > + * We stash away the first error we encounter in > + * wbc->saved_err so that it can be retrieved when we're > + * done. This is because the file system may still have > + * state to clear for each folio. > + * > + * For background writeback we exit as soon as we run > + * past wbc->nr_to_write or encounter the first error. > */ > - done_index = folio->index + nr; > - if (wbc->nr_to_write <= 0 && > - wbc->sync_mode == WB_SYNC_NONE) { > - done = 1; > - break; > + if (wbc->sync_mode == WB_SYNC_ALL) { > + if (error && !ret) > + ret = error; > + } else { > + if (error || wbc->nr_to_write <= 0) > + goto done; > } > } > folio_batch_release(&fbatch); > @@ -2524,14 +2505,15 @@ int write_cache_pages(struct address_space *mapping, > * of the file if we are called again, which can only happen due to > * -ENOMEM from the file system. > */ > - if (wbc->range_cyclic) { > - if (done) > - mapping->writeback_index = done_index; > - else > - mapping->writeback_index = 0; > - } > - > + if (wbc->range_cyclic) > + mapping->writeback_index = 0; > return ret; > + > +done: > + folio_batch_release(&fbatch); > + if (wbc->range_cyclic) > + mapping->writeback_index = folio->index + folio_nr_pages(folio); > + return error; > } > EXPORT_SYMBOL(write_cache_pages); > > -- > 2.39.2 >
On Sat, Feb 03, 2024 at 08:11:39AM +0100, Christoph Hellwig wrote: > Rework the way we deal with the cleanup after the writepage call. > > First handle the magic AOP_WRITEPAGE_ACTIVATE separately from real error > returns to get it out of the way of the actual error handling path. > > The split the handling on intgrity vs non-integrity branches first, > and return early using a goto for the non-ingegrity early loop condition > to remove the need for the done and done_index local variables, and for > assigning the error to ret when we can just return error directly. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > mm/page-writeback.c | 84 ++++++++++++++++++--------------------------- > 1 file changed, 33 insertions(+), 51 deletions(-) > > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index c7c494526bc650..88b2c4c111c01b 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c ... > @@ -2524,14 +2505,15 @@ int write_cache_pages(struct address_space *mapping, > * of the file if we are called again, which can only happen due to > * -ENOMEM from the file system. > */ > - if (wbc->range_cyclic) { > - if (done) > - mapping->writeback_index = done_index; > - else > - mapping->writeback_index = 0; > - } > - > + if (wbc->range_cyclic) > + mapping->writeback_index = 0; > return ret; > + > +done: > + folio_batch_release(&fbatch); > + if (wbc->range_cyclic) > + mapping->writeback_index = folio->index + folio_nr_pages(folio); Shouldn't this release the batch after we're done accessing folio? With that addressed: Reviewed-by: Brian Foster <bfoster@redhat.com> > + return error; > } > EXPORT_SYMBOL(write_cache_pages); > > -- > 2.39.2 > >
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index c7c494526bc650..88b2c4c111c01b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2396,13 +2396,12 @@ int write_cache_pages(struct address_space *mapping, void *data) { int ret = 0; - int done = 0; int error; struct folio_batch fbatch; + struct folio *folio; int nr_folios; pgoff_t index; pgoff_t end; /* Inclusive */ - pgoff_t done_index; xa_mark_t tag; folio_batch_init(&fbatch); @@ -2419,8 +2418,7 @@ int write_cache_pages(struct address_space *mapping, } else { tag = PAGECACHE_TAG_DIRTY; } - done_index = index; - while (!done && (index <= end)) { + while (index <= end) { int i; nr_folios = filemap_get_folios_tag(mapping, &index, end, @@ -2430,11 +2428,7 @@ int write_cache_pages(struct address_space *mapping, break; for (i = 0; i < nr_folios; i++) { - struct folio *folio = fbatch.folios[i]; - unsigned long nr; - - done_index = folio->index; - + folio = fbatch.folios[i]; folio_lock(folio); /* @@ -2469,45 +2463,32 @@ int write_cache_pages(struct address_space *mapping, trace_wbc_writepage(wbc, inode_to_bdi(mapping->host)); error = writepage(folio, wbc, data); - nr = folio_nr_pages(folio); - wbc->nr_to_write -= nr; - if (unlikely(error)) { - /* - * Handle errors according to the type of - * writeback. There's no need to continue for - * background writeback. Just push done_index - * past this page so media errors won't choke - * writeout for the entire file. For integrity - * writeback, we must process the entire dirty - * set regardless of errors because the fs may - * still have state to clear for each page. In - * that case we continue processing and return - * the first error. - */ - if (error == AOP_WRITEPAGE_ACTIVATE) { - folio_unlock(folio); - error = 0; - } else if (wbc->sync_mode != WB_SYNC_ALL) { - ret = error; - done_index = folio->index + nr; - done = 1; - break; - } - if (!ret) - ret = error; + wbc->nr_to_write -= folio_nr_pages(folio); + + if (error == AOP_WRITEPAGE_ACTIVATE) { + folio_unlock(folio); + error = 0; } /* - * We stop writing back only if we are not doing - * integrity sync. In case of integrity sync we have to - * keep going until we have written all the pages - * we tagged for writeback prior to entering this loop. + * For integrity writeback we have to keep going until + * we have written all the folios we tagged for + * writeback above, even if we run past wbc->nr_to_write + * or encounter errors. + * We stash away the first error we encounter in + * wbc->saved_err so that it can be retrieved when we're + * done. This is because the file system may still have + * state to clear for each folio. + * + * For background writeback we exit as soon as we run + * past wbc->nr_to_write or encounter the first error. */ - done_index = folio->index + nr; - if (wbc->nr_to_write <= 0 && - wbc->sync_mode == WB_SYNC_NONE) { - done = 1; - break; + if (wbc->sync_mode == WB_SYNC_ALL) { + if (error && !ret) + ret = error; + } else { + if (error || wbc->nr_to_write <= 0) + goto done; } } folio_batch_release(&fbatch); @@ -2524,14 +2505,15 @@ int write_cache_pages(struct address_space *mapping, * of the file if we are called again, which can only happen due to * -ENOMEM from the file system. */ - if (wbc->range_cyclic) { - if (done) - mapping->writeback_index = done_index; - else - mapping->writeback_index = 0; - } - + if (wbc->range_cyclic) + mapping->writeback_index = 0; return ret; + +done: + folio_batch_release(&fbatch); + if (wbc->range_cyclic) + mapping->writeback_index = folio->index + folio_nr_pages(folio); + return error; } EXPORT_SYMBOL(write_cache_pages);
Rework the way we deal with the cleanup after the writepage call. First handle the magic AOP_WRITEPAGE_ACTIVATE separately from real error returns to get it out of the way of the actual error handling path. The split the handling on intgrity vs non-integrity branches first, and return early using a goto for the non-ingegrity early loop condition to remove the need for the done and done_index local variables, and for assigning the error to ret when we can just return error directly. Signed-off-by: Christoph Hellwig <hch@lst.de> --- mm/page-writeback.c | 84 ++++++++++++++++++--------------------------- 1 file changed, 33 insertions(+), 51 deletions(-)