| Message ID | 20221125190642.12787-1-ebiggers@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4] fsverity: stop using PG_error to track error status | expand |
On 11/25, Eric Biggers wrote: > From: Eric Biggers <ebiggers@google.com> > > As a step towards freeing the PG_error flag for other uses, change ext4 > and f2fs to stop using PG_error to track verity errors. Instead, if a > verity error occurs, just mark the whole bio as failed. The coarser > granularity isn't really a problem since it isn't any worse than what > the block layer provides, and errors from a multi-page readahead aren't > reported to applications unless a single-page read fails too. > > f2fs supports compression, which makes the f2fs changes a bit more > complicated than desired, but the basic premise still works. > > Note: there are still a few uses of PageError in f2fs, but they are on > the write path, so they are unrelated and this patch doesn't touch them. > > Reviewed-by: Chao Yu <chao@kernel.org> Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> Thanks, > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > > v4: Added a comment for decompression_attempted, added a paragraph to > the commit message, and added Chao's Reviewed-by. > > v3: made a small simplification to the f2fs changes. Also dropped the > fscrypt patch since it is upstream now. > > fs/ext4/readpage.c | 8 ++---- > fs/f2fs/compress.c | 64 ++++++++++++++++++++++------------------------ > fs/f2fs/data.c | 53 +++++++++++++++++++++++--------------- > fs/verity/verify.c | 12 ++++----- > 4 files changed, 72 insertions(+), 65 deletions(-) > > diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c > index 3d21eae267fca..e604ea4e102b7 100644 > --- a/fs/ext4/readpage.c > +++ b/fs/ext4/readpage.c > @@ -75,14 +75,10 @@ static void __read_end_io(struct bio *bio) > bio_for_each_segment_all(bv, bio, iter_all) { > page = bv->bv_page; > > - /* PG_error was set if verity failed. */ > - if (bio->bi_status || PageError(page)) { > + if (bio->bi_status) > ClearPageUptodate(page); > - /* will re-read again later */ > - ClearPageError(page); > - } else { > + else > SetPageUptodate(page); > - } > unlock_page(page); > } > if (bio->bi_private) > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c > index d315c2de136f2..2b7a5cc4ed662 100644 > --- a/fs/f2fs/compress.c > +++ b/fs/f2fs/compress.c > @@ -1711,50 +1711,27 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task) > } > } > > -/* > - * Update and unlock the cluster's pagecache pages, and release the reference to > - * the decompress_io_ctx that was being held for I/O completion. > - */ > -static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > - bool in_task) > +static void f2fs_verify_cluster(struct work_struct *work) > { > + struct decompress_io_ctx *dic = > + container_of(work, struct decompress_io_ctx, verity_work); > int i; > > + /* Verify, update, and unlock the decompressed pages. */ > for (i = 0; i < dic->cluster_size; i++) { > struct page *rpage = dic->rpages[i]; > > if (!rpage) > continue; > > - /* PG_error was set if verity failed. */ > - if (failed || PageError(rpage)) { > - ClearPageUptodate(rpage); > - /* will re-read again later */ > - ClearPageError(rpage); > - } else { > + if (fsverity_verify_page(rpage)) > SetPageUptodate(rpage); > - } > + else > + ClearPageUptodate(rpage); > unlock_page(rpage); > } > > - f2fs_put_dic(dic, in_task); > -} > - > -static void f2fs_verify_cluster(struct work_struct *work) > -{ > - struct decompress_io_ctx *dic = > - container_of(work, struct decompress_io_ctx, verity_work); > - int i; > - > - /* Verify the cluster's decompressed pages with fs-verity. */ > - for (i = 0; i < dic->cluster_size; i++) { > - struct page *rpage = dic->rpages[i]; > - > - if (rpage && !fsverity_verify_page(rpage)) > - SetPageError(rpage); > - } > - > - __f2fs_decompress_end_io(dic, false, true); > + f2fs_put_dic(dic, true); > } > > /* > @@ -1764,6 +1741,8 @@ static void f2fs_verify_cluster(struct work_struct *work) > void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > bool in_task) > { > + int i; > + > if (!failed && dic->need_verity) { > /* > * Note that to avoid deadlocks, the verity work can't be done > @@ -1773,9 +1752,28 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > */ > INIT_WORK(&dic->verity_work, f2fs_verify_cluster); > fsverity_enqueue_verify_work(&dic->verity_work); > - } else { > - __f2fs_decompress_end_io(dic, failed, in_task); > + return; > + } > + > + /* Update and unlock the cluster's pagecache pages. */ > + for (i = 0; i < dic->cluster_size; i++) { > + struct page *rpage = dic->rpages[i]; > + > + if (!rpage) > + continue; > + > + if (failed) > + ClearPageUptodate(rpage); > + else > + SetPageUptodate(rpage); > + unlock_page(rpage); > } > + > + /* > + * Release the reference to the decompress_io_ctx that was being held > + * for I/O completion. > + */ > + f2fs_put_dic(dic, in_task); > } > > /* > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index a71e818cd67b4..1ae8da259d6c5 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -116,43 +116,56 @@ struct bio_post_read_ctx { > struct f2fs_sb_info *sbi; > struct work_struct work; > unsigned int enabled_steps; > + /* > + * decompression_attempted keeps track of whether > + * f2fs_end_read_compressed_page() has been called on the pages in the > + * bio that belong to a compressed cluster yet. > + */ > + bool decompression_attempted; > block_t fs_blkaddr; > }; > > +/* > + * Update and unlock a bio's pages, and free the bio. > + * > + * This marks pages up-to-date only if there was no error in the bio (I/O error, > + * decryption error, or verity error), as indicated by bio->bi_status. > + * > + * "Compressed pages" (pagecache pages backed by a compressed cluster on-disk) > + * aren't marked up-to-date here, as decompression is done on a per-compression- > + * cluster basis rather than a per-bio basis. Instead, we only must do two > + * things for each compressed page here: call f2fs_end_read_compressed_page() > + * with failed=true if an error occurred before it would have normally gotten > + * called (i.e., I/O error or decryption error, but *not* verity error), and > + * release the bio's reference to the decompress_io_ctx of the page's cluster. > + */ > static void f2fs_finish_read_bio(struct bio *bio, bool in_task) > { > struct bio_vec *bv; > struct bvec_iter_all iter_all; > + struct bio_post_read_ctx *ctx = bio->bi_private; > > - /* > - * Update and unlock the bio's pagecache pages, and put the > - * decompression context for any compressed pages. > - */ > bio_for_each_segment_all(bv, bio, iter_all) { > struct page *page = bv->bv_page; > > if (f2fs_is_compressed_page(page)) { > - if (bio->bi_status) > + if (!ctx->decompression_attempted) > f2fs_end_read_compressed_page(page, true, 0, > in_task); > f2fs_put_page_dic(page, in_task); > continue; > } > > - /* PG_error was set if verity failed. */ > - if (bio->bi_status || PageError(page)) { > + if (bio->bi_status) > ClearPageUptodate(page); > - /* will re-read again later */ > - ClearPageError(page); > - } else { > + else > SetPageUptodate(page); > - } > dec_page_count(F2FS_P_SB(page), __read_io_type(page)); > unlock_page(page); > } > > - if (bio->bi_private) > - mempool_free(bio->bi_private, bio_post_read_ctx_pool); > + if (ctx) > + mempool_free(ctx, bio_post_read_ctx_pool); > bio_put(bio); > } > > @@ -185,8 +198,10 @@ static void f2fs_verify_bio(struct work_struct *work) > struct page *page = bv->bv_page; > > if (!f2fs_is_compressed_page(page) && > - !fsverity_verify_page(page)) > - SetPageError(page); > + !fsverity_verify_page(page)) { > + bio->bi_status = BLK_STS_IOERR; > + break; > + } > } > } else { > fsverity_verify_bio(bio); > @@ -245,6 +260,8 @@ static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx, > blkaddr++; > } > > + ctx->decompression_attempted = true; > + > /* > * Optimization: if all the bio's pages are compressed, then scheduling > * the per-bio verity work is unnecessary, as verity will be fully > @@ -1062,6 +1079,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, > ctx->sbi = sbi; > ctx->enabled_steps = post_read_steps; > ctx->fs_blkaddr = blkaddr; > + ctx->decompression_attempted = false; > bio->bi_private = ctx; > } > iostat_alloc_and_bind_ctx(sbi, bio, ctx); > @@ -1089,7 +1107,6 @@ static int f2fs_submit_page_read(struct inode *inode, struct page *page, > bio_put(bio); > return -EFAULT; > } > - ClearPageError(page); > inc_page_count(sbi, F2FS_RD_DATA); > f2fs_update_iostat(sbi, NULL, FS_DATA_READ_IO, F2FS_BLKSIZE); > __submit_bio(sbi, bio, DATA); > @@ -2141,7 +2158,6 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page, > inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA); > f2fs_update_iostat(F2FS_I_SB(inode), NULL, FS_DATA_READ_IO, > F2FS_BLKSIZE); > - ClearPageError(page); > *last_block_in_bio = block_nr; > goto out; > out: > @@ -2289,7 +2305,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > > inc_page_count(sbi, F2FS_RD_DATA); > f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE); > - ClearPageError(page); > *last_block_in_bio = blkaddr; > } > > @@ -2306,7 +2321,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > for (i = 0; i < cc->cluster_size; i++) { > if (cc->rpages[i]) { > ClearPageUptodate(cc->rpages[i]); > - ClearPageError(cc->rpages[i]); > unlock_page(cc->rpages[i]); > } > } > @@ -2403,7 +2417,6 @@ static int f2fs_mpage_readpages(struct inode *inode, > #ifdef CONFIG_F2FS_FS_COMPRESSION > set_error_page: > #endif > - SetPageError(page); > zero_user_segment(page, 0, PAGE_SIZE); > unlock_page(page); > } > diff --git a/fs/verity/verify.c b/fs/verity/verify.c > index bde8c9b7d25f6..961ba248021f9 100644 > --- a/fs/verity/verify.c > +++ b/fs/verity/verify.c > @@ -200,9 +200,8 @@ EXPORT_SYMBOL_GPL(fsverity_verify_page); > * @bio: the bio to verify > * > * Verify a set of pages that have just been read from a verity file. The pages > - * must be pagecache pages that are still locked and not yet uptodate. Pages > - * that fail verification are set to the Error state. Verification is skipped > - * for pages already in the Error state, e.g. due to fscrypt decryption failure. > + * must be pagecache pages that are still locked and not yet uptodate. If a > + * page fails verification, then bio->bi_status is set to an error status. > * > * This is a helper function for use by the ->readahead() method of filesystems > * that issue bios to read data directly into the page cache. Filesystems that > @@ -244,9 +243,10 @@ void fsverity_verify_bio(struct bio *bio) > unsigned long level0_ra_pages = > min(max_ra_pages, params->level0_blocks - level0_index); > > - if (!PageError(page) && > - !verify_page(inode, vi, req, page, level0_ra_pages)) > - SetPageError(page); > + if (!verify_page(inode, vi, req, page, level0_ra_pages)) { > + bio->bi_status = BLK_STS_IOERR; > + break; > + } > } > > fsverity_free_hash_request(params->hash_alg, req); > > base-commit: f0c4d9fc9cc9462659728d168387191387e903cc > -- > 2.38.1
On 11/25, Eric Biggers wrote: > From: Eric Biggers <ebiggers@google.com> > > As a step towards freeing the PG_error flag for other uses, change ext4 > and f2fs to stop using PG_error to track verity errors. Instead, if a > verity error occurs, just mark the whole bio as failed. The coarser > granularity isn't really a problem since it isn't any worse than what > the block layer provides, and errors from a multi-page readahead aren't > reported to applications unless a single-page read fails too. > > f2fs supports compression, which makes the f2fs changes a bit more > complicated than desired, but the basic premise still works. > > Note: there are still a few uses of PageError in f2fs, but they are on > the write path, so they are unrelated and this patch doesn't touch them. > > Reviewed-by: Chao Yu <chao@kernel.org> > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > > v4: Added a comment for decompression_attempted, added a paragraph to > the commit message, and added Chao's Reviewed-by. > > v3: made a small simplification to the f2fs changes. Also dropped the > fscrypt patch since it is upstream now. > > fs/ext4/readpage.c | 8 ++---- > fs/f2fs/compress.c | 64 ++++++++++++++++++++++------------------------ > fs/f2fs/data.c | 53 +++++++++++++++++++++++--------------- > fs/verity/verify.c | 12 ++++----- > 4 files changed, 72 insertions(+), 65 deletions(-) > > diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c > index 3d21eae267fca..e604ea4e102b7 100644 > --- a/fs/ext4/readpage.c > +++ b/fs/ext4/readpage.c > @@ -75,14 +75,10 @@ static void __read_end_io(struct bio *bio) > bio_for_each_segment_all(bv, bio, iter_all) { > page = bv->bv_page; > > - /* PG_error was set if verity failed. */ > - if (bio->bi_status || PageError(page)) { > + if (bio->bi_status) > ClearPageUptodate(page); > - /* will re-read again later */ > - ClearPageError(page); > - } else { > + else > SetPageUptodate(page); > - } > unlock_page(page); > } > if (bio->bi_private) > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c > index d315c2de136f2..2b7a5cc4ed662 100644 > --- a/fs/f2fs/compress.c > +++ b/fs/f2fs/compress.c > @@ -1711,50 +1711,27 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task) > } > } > > -/* > - * Update and unlock the cluster's pagecache pages, and release the reference to > - * the decompress_io_ctx that was being held for I/O completion. > - */ > -static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > - bool in_task) > +static void f2fs_verify_cluster(struct work_struct *work) > { > + struct decompress_io_ctx *dic = > + container_of(work, struct decompress_io_ctx, verity_work); > int i; > > + /* Verify, update, and unlock the decompressed pages. */ > for (i = 0; i < dic->cluster_size; i++) { > struct page *rpage = dic->rpages[i]; > > if (!rpage) > continue; > > - /* PG_error was set if verity failed. */ > - if (failed || PageError(rpage)) { > - ClearPageUptodate(rpage); > - /* will re-read again later */ > - ClearPageError(rpage); > - } else { > + if (fsverity_verify_page(rpage)) > SetPageUptodate(rpage); > - } > + else > + ClearPageUptodate(rpage); > unlock_page(rpage); > } > > - f2fs_put_dic(dic, in_task); > -} > - > -static void f2fs_verify_cluster(struct work_struct *work) > -{ > - struct decompress_io_ctx *dic = > - container_of(work, struct decompress_io_ctx, verity_work); > - int i; > - > - /* Verify the cluster's decompressed pages with fs-verity. */ > - for (i = 0; i < dic->cluster_size; i++) { > - struct page *rpage = dic->rpages[i]; > - > - if (rpage && !fsverity_verify_page(rpage)) > - SetPageError(rpage); > - } > - > - __f2fs_decompress_end_io(dic, false, true); > + f2fs_put_dic(dic, true); > } > > /* > @@ -1764,6 +1741,8 @@ static void f2fs_verify_cluster(struct work_struct *work) > void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > bool in_task) > { > + int i; > + > if (!failed && dic->need_verity) { > /* > * Note that to avoid deadlocks, the verity work can't be done > @@ -1773,9 +1752,28 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > */ > INIT_WORK(&dic->verity_work, f2fs_verify_cluster); > fsverity_enqueue_verify_work(&dic->verity_work); > - } else { > - __f2fs_decompress_end_io(dic, failed, in_task); > + return; > + } > + > + /* Update and unlock the cluster's pagecache pages. */ > + for (i = 0; i < dic->cluster_size; i++) { > + struct page *rpage = dic->rpages[i]; > + > + if (!rpage) > + continue; > + > + if (failed) > + ClearPageUptodate(rpage); > + else > + SetPageUptodate(rpage); > + unlock_page(rpage); > } > + > + /* > + * Release the reference to the decompress_io_ctx that was being held > + * for I/O completion. > + */ > + f2fs_put_dic(dic, in_task); > } > > /* > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index a71e818cd67b4..1ae8da259d6c5 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -116,43 +116,56 @@ struct bio_post_read_ctx { > struct f2fs_sb_info *sbi; > struct work_struct work; > unsigned int enabled_steps; > + /* > + * decompression_attempted keeps track of whether > + * f2fs_end_read_compressed_page() has been called on the pages in the > + * bio that belong to a compressed cluster yet. > + */ > + bool decompression_attempted; > block_t fs_blkaddr; > }; > > +/* > + * Update and unlock a bio's pages, and free the bio. > + * > + * This marks pages up-to-date only if there was no error in the bio (I/O error, > + * decryption error, or verity error), as indicated by bio->bi_status. > + * > + * "Compressed pages" (pagecache pages backed by a compressed cluster on-disk) > + * aren't marked up-to-date here, as decompression is done on a per-compression- > + * cluster basis rather than a per-bio basis. Instead, we only must do two > + * things for each compressed page here: call f2fs_end_read_compressed_page() > + * with failed=true if an error occurred before it would have normally gotten > + * called (i.e., I/O error or decryption error, but *not* verity error), and > + * release the bio's reference to the decompress_io_ctx of the page's cluster. > + */ > static void f2fs_finish_read_bio(struct bio *bio, bool in_task) > { > struct bio_vec *bv; > struct bvec_iter_all iter_all; > + struct bio_post_read_ctx *ctx = bio->bi_private; > > - /* > - * Update and unlock the bio's pagecache pages, and put the > - * decompression context for any compressed pages. > - */ > bio_for_each_segment_all(bv, bio, iter_all) { > struct page *page = bv->bv_page; > > if (f2fs_is_compressed_page(page)) { > - if (bio->bi_status) > + if (!ctx->decompression_attempted) If seems this causes a panic due to the ctx nullified by f2fs_verify_bio. > f2fs_end_read_compressed_page(page, true, 0, > in_task); > f2fs_put_page_dic(page, in_task); > continue; > } > > - /* PG_error was set if verity failed. */ > - if (bio->bi_status || PageError(page)) { > + if (bio->bi_status) > ClearPageUptodate(page); > - /* will re-read again later */ > - ClearPageError(page); > - } else { > + else > SetPageUptodate(page); > - } > dec_page_count(F2FS_P_SB(page), __read_io_type(page)); > unlock_page(page); > } > > - if (bio->bi_private) > - mempool_free(bio->bi_private, bio_post_read_ctx_pool); > + if (ctx) > + mempool_free(ctx, bio_post_read_ctx_pool); > bio_put(bio); > } > > @@ -185,8 +198,10 @@ static void f2fs_verify_bio(struct work_struct *work) > struct page *page = bv->bv_page; > > if (!f2fs_is_compressed_page(page) && > - !fsverity_verify_page(page)) > - SetPageError(page); > + !fsverity_verify_page(page)) { > + bio->bi_status = BLK_STS_IOERR; > + break; > + } > } > } else { > fsverity_verify_bio(bio); > @@ -245,6 +260,8 @@ static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx, > blkaddr++; > } > > + ctx->decompression_attempted = true; > + > /* > * Optimization: if all the bio's pages are compressed, then scheduling > * the per-bio verity work is unnecessary, as verity will be fully > @@ -1062,6 +1079,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, > ctx->sbi = sbi; > ctx->enabled_steps = post_read_steps; > ctx->fs_blkaddr = blkaddr; > + ctx->decompression_attempted = false; > bio->bi_private = ctx; > } > iostat_alloc_and_bind_ctx(sbi, bio, ctx); > @@ -1089,7 +1107,6 @@ static int f2fs_submit_page_read(struct inode *inode, struct page *page, > bio_put(bio); > return -EFAULT; > } > - ClearPageError(page); > inc_page_count(sbi, F2FS_RD_DATA); > f2fs_update_iostat(sbi, NULL, FS_DATA_READ_IO, F2FS_BLKSIZE); > __submit_bio(sbi, bio, DATA); > @@ -2141,7 +2158,6 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page, > inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA); > f2fs_update_iostat(F2FS_I_SB(inode), NULL, FS_DATA_READ_IO, > F2FS_BLKSIZE); > - ClearPageError(page); > *last_block_in_bio = block_nr; > goto out; > out: > @@ -2289,7 +2305,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > > inc_page_count(sbi, F2FS_RD_DATA); > f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE); > - ClearPageError(page); > *last_block_in_bio = blkaddr; > } > > @@ -2306,7 +2321,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > for (i = 0; i < cc->cluster_size; i++) { > if (cc->rpages[i]) { > ClearPageUptodate(cc->rpages[i]); > - ClearPageError(cc->rpages[i]); > unlock_page(cc->rpages[i]); > } > } > @@ -2403,7 +2417,6 @@ static int f2fs_mpage_readpages(struct inode *inode, > #ifdef CONFIG_F2FS_FS_COMPRESSION > set_error_page: > #endif > - SetPageError(page); > zero_user_segment(page, 0, PAGE_SIZE); > unlock_page(page); > } > diff --git a/fs/verity/verify.c b/fs/verity/verify.c > index bde8c9b7d25f6..961ba248021f9 100644 > --- a/fs/verity/verify.c > +++ b/fs/verity/verify.c > @@ -200,9 +200,8 @@ EXPORT_SYMBOL_GPL(fsverity_verify_page); > * @bio: the bio to verify > * > * Verify a set of pages that have just been read from a verity file. The pages > - * must be pagecache pages that are still locked and not yet uptodate. Pages > - * that fail verification are set to the Error state. Verification is skipped > - * for pages already in the Error state, e.g. due to fscrypt decryption failure. > + * must be pagecache pages that are still locked and not yet uptodate. If a > + * page fails verification, then bio->bi_status is set to an error status. > * > * This is a helper function for use by the ->readahead() method of filesystems > * that issue bios to read data directly into the page cache. Filesystems that > @@ -244,9 +243,10 @@ void fsverity_verify_bio(struct bio *bio) > unsigned long level0_ra_pages = > min(max_ra_pages, params->level0_blocks - level0_index); > > - if (!PageError(page) && > - !verify_page(inode, vi, req, page, level0_ra_pages)) > - SetPageError(page); > + if (!verify_page(inode, vi, req, page, level0_ra_pages)) { > + bio->bi_status = BLK_STS_IOERR; > + break; > + } > } > > fsverity_free_hash_request(params->hash_alg, req); > > base-commit: f0c4d9fc9cc9462659728d168387191387e903cc > -- > 2.38.1
On Mon, Nov 28, 2022 at 10:48:41PM -0800, Jaegeuk Kim wrote: > > static void f2fs_finish_read_bio(struct bio *bio, bool in_task) > > { > > struct bio_vec *bv; > > struct bvec_iter_all iter_all; > > + struct bio_post_read_ctx *ctx = bio->bi_private; > > > > - /* > > - * Update and unlock the bio's pagecache pages, and put the > > - * decompression context for any compressed pages. > > - */ > > bio_for_each_segment_all(bv, bio, iter_all) { > > struct page *page = bv->bv_page; > > > > if (f2fs_is_compressed_page(page)) { > > - if (bio->bi_status) > > + if (!ctx->decompression_attempted) > > If seems this causes a panic due to the ctx nullified by f2fs_verify_bio. > Thanks for catching that! I've sent out v5 that checks for 'ctx && !ctx->decompression_attempted' here. That's the right thing to do, since if ctx is NULL then decompression must have been attempted. I'd like to get rid of freeing the bio_post_read_ctx in f2fs_verify_bio(). But I believe it's still needed, at least in theory. Do you have a suggestion for testing f2fs compression + verity with xfstests? I missed this because compression isn't covered by the "verity" group tests. Maybe there should be an "f2fs/compress" config in xfstests-bld that uses mkfs and mount options that cause all files to be automatically compressed, similar to how f2fs/encrypt automatically encrypts all files with test_dummy_encryption. - Eric
On 11/28, Eric Biggers wrote: > On Mon, Nov 28, 2022 at 10:48:41PM -0800, Jaegeuk Kim wrote: > > > static void f2fs_finish_read_bio(struct bio *bio, bool in_task) > > > { > > > struct bio_vec *bv; > > > struct bvec_iter_all iter_all; > > > + struct bio_post_read_ctx *ctx = bio->bi_private; > > > > > > - /* > > > - * Update and unlock the bio's pagecache pages, and put the > > > - * decompression context for any compressed pages. > > > - */ > > > bio_for_each_segment_all(bv, bio, iter_all) { > > > struct page *page = bv->bv_page; > > > > > > if (f2fs_is_compressed_page(page)) { > > > - if (bio->bi_status) > > > + if (!ctx->decompression_attempted) > > > > If seems this causes a panic due to the ctx nullified by f2fs_verify_bio. > > > > Thanks for catching that! I've sent out v5 that checks for 'ctx && > !ctx->decompression_attempted' here. That's the right thing to do, since if ctx > is NULL then decompression must have been attempted. > > I'd like to get rid of freeing the bio_post_read_ctx in f2fs_verify_bio(). > But I believe it's still needed, at least in theory. > > Do you have a suggestion for testing f2fs compression + verity with xfstests? > I missed this because compression isn't covered by the "verity" group tests. > Maybe there should be an "f2fs/compress" config in xfstests-bld that uses mkfs > and mount options that cause all files to be automatically compressed, similar > to how f2fs/encrypt automatically encrypts all files with test_dummy_encryption. I used for fsstress+fault_injection+shutdown loop with compressed and non-compressed directories with: # mkfs.f2fs -f -O extra_attr -O project_quota -O compression -g android /dev/$DEV # mount -t f2fs -o discard,fsync_mode=nobarrier,reserve_root=32768,checkpoint_merge,atgc,compress_cache /dev/$DEV $TESTDIR # mkdir $TESTDIR/comp # f2fs_io setflags compression $TESTDIR/comp # fsstress [options] -d $TESTDIR/comp I think you can simply mount with "-o compress_extension=*" to compress everything. > > - Eric
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c index 3d21eae267fca..e604ea4e102b7 100644 --- a/fs/ext4/readpage.c +++ b/fs/ext4/readpage.c @@ -75,14 +75,10 @@ static void __read_end_io(struct bio *bio) bio_for_each_segment_all(bv, bio, iter_all) { page = bv->bv_page; - /* PG_error was set if verity failed. */ - if (bio->bi_status || PageError(page)) { + if (bio->bi_status) ClearPageUptodate(page); - /* will re-read again later */ - ClearPageError(page); - } else { + else SetPageUptodate(page); - } unlock_page(page); } if (bio->bi_private) diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index d315c2de136f2..2b7a5cc4ed662 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1711,50 +1711,27 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task) } } -/* - * Update and unlock the cluster's pagecache pages, and release the reference to - * the decompress_io_ctx that was being held for I/O completion. - */ -static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, - bool in_task) +static void f2fs_verify_cluster(struct work_struct *work) { + struct decompress_io_ctx *dic = + container_of(work, struct decompress_io_ctx, verity_work); int i; + /* Verify, update, and unlock the decompressed pages. */ for (i = 0; i < dic->cluster_size; i++) { struct page *rpage = dic->rpages[i]; if (!rpage) continue; - /* PG_error was set if verity failed. */ - if (failed || PageError(rpage)) { - ClearPageUptodate(rpage); - /* will re-read again later */ - ClearPageError(rpage); - } else { + if (fsverity_verify_page(rpage)) SetPageUptodate(rpage); - } + else + ClearPageUptodate(rpage); unlock_page(rpage); } - f2fs_put_dic(dic, in_task); -} - -static void f2fs_verify_cluster(struct work_struct *work) -{ - struct decompress_io_ctx *dic = - container_of(work, struct decompress_io_ctx, verity_work); - int i; - - /* Verify the cluster's decompressed pages with fs-verity. */ - for (i = 0; i < dic->cluster_size; i++) { - struct page *rpage = dic->rpages[i]; - - if (rpage && !fsverity_verify_page(rpage)) - SetPageError(rpage); - } - - __f2fs_decompress_end_io(dic, false, true); + f2fs_put_dic(dic, true); } /* @@ -1764,6 +1741,8 @@ static void f2fs_verify_cluster(struct work_struct *work) void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, bool in_task) { + int i; + if (!failed && dic->need_verity) { /* * Note that to avoid deadlocks, the verity work can't be done @@ -1773,9 +1752,28 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, */ INIT_WORK(&dic->verity_work, f2fs_verify_cluster); fsverity_enqueue_verify_work(&dic->verity_work); - } else { - __f2fs_decompress_end_io(dic, failed, in_task); + return; + } + + /* Update and unlock the cluster's pagecache pages. */ + for (i = 0; i < dic->cluster_size; i++) { + struct page *rpage = dic->rpages[i]; + + if (!rpage) + continue; + + if (failed) + ClearPageUptodate(rpage); + else + SetPageUptodate(rpage); + unlock_page(rpage); } + + /* + * Release the reference to the decompress_io_ctx that was being held + * for I/O completion. + */ + f2fs_put_dic(dic, in_task); } /* diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a71e818cd67b4..1ae8da259d6c5 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -116,43 +116,56 @@ struct bio_post_read_ctx { struct f2fs_sb_info *sbi; struct work_struct work; unsigned int enabled_steps; + /* + * decompression_attempted keeps track of whether + * f2fs_end_read_compressed_page() has been called on the pages in the + * bio that belong to a compressed cluster yet. + */ + bool decompression_attempted; block_t fs_blkaddr; }; +/* + * Update and unlock a bio's pages, and free the bio. + * + * This marks pages up-to-date only if there was no error in the bio (I/O error, + * decryption error, or verity error), as indicated by bio->bi_status. + * + * "Compressed pages" (pagecache pages backed by a compressed cluster on-disk) + * aren't marked up-to-date here, as decompression is done on a per-compression- + * cluster basis rather than a per-bio basis. Instead, we only must do two + * things for each compressed page here: call f2fs_end_read_compressed_page() + * with failed=true if an error occurred before it would have normally gotten + * called (i.e., I/O error or decryption error, but *not* verity error), and + * release the bio's reference to the decompress_io_ctx of the page's cluster. + */ static void f2fs_finish_read_bio(struct bio *bio, bool in_task) { struct bio_vec *bv; struct bvec_iter_all iter_all; + struct bio_post_read_ctx *ctx = bio->bi_private; - /* - * Update and unlock the bio's pagecache pages, and put the - * decompression context for any compressed pages. - */ bio_for_each_segment_all(bv, bio, iter_all) { struct page *page = bv->bv_page; if (f2fs_is_compressed_page(page)) { - if (bio->bi_status) + if (!ctx->decompression_attempted) f2fs_end_read_compressed_page(page, true, 0, in_task); f2fs_put_page_dic(page, in_task); continue; } - /* PG_error was set if verity failed. */ - if (bio->bi_status || PageError(page)) { + if (bio->bi_status) ClearPageUptodate(page); - /* will re-read again later */ - ClearPageError(page); - } else { + else SetPageUptodate(page); - } dec_page_count(F2FS_P_SB(page), __read_io_type(page)); unlock_page(page); } - if (bio->bi_private) - mempool_free(bio->bi_private, bio_post_read_ctx_pool); + if (ctx) + mempool_free(ctx, bio_post_read_ctx_pool); bio_put(bio); } @@ -185,8 +198,10 @@ static void f2fs_verify_bio(struct work_struct *work) struct page *page = bv->bv_page; if (!f2fs_is_compressed_page(page) && - !fsverity_verify_page(page)) - SetPageError(page); + !fsverity_verify_page(page)) { + bio->bi_status = BLK_STS_IOERR; + break; + } } } else { fsverity_verify_bio(bio); @@ -245,6 +260,8 @@ static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx, blkaddr++; } + ctx->decompression_attempted = true; + /* * Optimization: if all the bio's pages are compressed, then scheduling * the per-bio verity work is unnecessary, as verity will be fully @@ -1062,6 +1079,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, ctx->sbi = sbi; ctx->enabled_steps = post_read_steps; ctx->fs_blkaddr = blkaddr; + ctx->decompression_attempted = false; bio->bi_private = ctx; } iostat_alloc_and_bind_ctx(sbi, bio, ctx); @@ -1089,7 +1107,6 @@ static int f2fs_submit_page_read(struct inode *inode, struct page *page, bio_put(bio); return -EFAULT; } - ClearPageError(page); inc_page_count(sbi, F2FS_RD_DATA); f2fs_update_iostat(sbi, NULL, FS_DATA_READ_IO, F2FS_BLKSIZE); __submit_bio(sbi, bio, DATA); @@ -2141,7 +2158,6 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page, inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA); f2fs_update_iostat(F2FS_I_SB(inode), NULL, FS_DATA_READ_IO, F2FS_BLKSIZE); - ClearPageError(page); *last_block_in_bio = block_nr; goto out; out: @@ -2289,7 +2305,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, inc_page_count(sbi, F2FS_RD_DATA); f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE); - ClearPageError(page); *last_block_in_bio = blkaddr; } @@ -2306,7 +2321,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, for (i = 0; i < cc->cluster_size; i++) { if (cc->rpages[i]) { ClearPageUptodate(cc->rpages[i]); - ClearPageError(cc->rpages[i]); unlock_page(cc->rpages[i]); } } @@ -2403,7 +2417,6 @@ static int f2fs_mpage_readpages(struct inode *inode, #ifdef CONFIG_F2FS_FS_COMPRESSION set_error_page: #endif - SetPageError(page); zero_user_segment(page, 0, PAGE_SIZE); unlock_page(page); } diff --git a/fs/verity/verify.c b/fs/verity/verify.c index bde8c9b7d25f6..961ba248021f9 100644 --- a/fs/verity/verify.c +++ b/fs/verity/verify.c @@ -200,9 +200,8 @@ EXPORT_SYMBOL_GPL(fsverity_verify_page); * @bio: the bio to verify * * Verify a set of pages that have just been read from a verity file. The pages - * must be pagecache pages that are still locked and not yet uptodate. Pages - * that fail verification are set to the Error state. Verification is skipped - * for pages already in the Error state, e.g. due to fscrypt decryption failure. + * must be pagecache pages that are still locked and not yet uptodate. If a + * page fails verification, then bio->bi_status is set to an error status. * * This is a helper function for use by the ->readahead() method of filesystems * that issue bios to read data directly into the page cache. Filesystems that @@ -244,9 +243,10 @@ void fsverity_verify_bio(struct bio *bio) unsigned long level0_ra_pages = min(max_ra_pages, params->level0_blocks - level0_index); - if (!PageError(page) && - !verify_page(inode, vi, req, page, level0_ra_pages)) - SetPageError(page); + if (!verify_page(inode, vi, req, page, level0_ra_pages)) { + bio->bi_status = BLK_STS_IOERR; + break; + } } fsverity_free_hash_request(params->hash_alg, req);