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Wong" , Carlos Maiolino , Alexander Viro , Jan Kara , Christoph Hellwig Cc: Dave Chinner , Bart Van Assche , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Gao Xiang , Tal Zussman X-Mailer: b4 0.14.3-dev-d7477 X-Developer-Signature: v=1; a=ed25519-sha256; t=1778795507; l=3250; i=tz2294@columbia.edu; s=20250528; h=from:subject:message-id; bh=5MBJYs1Ny9I8ogr/547ALSAn0Pj03wWQCXtJIb2TJHQ=; b=9bQ2fojDINOqvoN+XUOT5/4ajyDiEcYRuoe/toJiMW2IYEErMQPP4nWP0kyaFXtYEdFs8QavD IoIc3c+yGL9AJoDL8xs3GhMcj/KZ4S3T3QanBUhqIizKxZ8785C3SWR X-Developer-Key: i=tz2294@columbia.edu; a=ed25519; pk=BIj5KdACscEOyAC0oIkeZqLB3L94fzBnDccEooxeM5Y= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNTE0MDIxNiBTYWx0ZWRfXyBU01EBooone 4P+38Da5q+EFDU6JswXgZcGkZlkbu4qFukVkGeru31zEWaYyesDnIJX8XRewoI9J9e6fJGm1Quq VPD1ymHC/EmXv4Gj+YPzs77QZZuBeWCqLJPQh0SxArNYjUwy+hzlP//eqxYuNkt0n0CAo2tlWvt vdzxJEvkJnReCnl9u9QdralUxnz5foT9vk3Egnc7KkiAvDzYFWBotyPTf1YF8M9X1q0ixwh+wMv TnlHJyQNu6+1eG8w4SxrO+UViyDkF11e37Yxk28q3Sdv/P5VOWhrfEgHkZTXgDQryiP6aX0xhgl A3KrrplGYTYE0NbYJPRmEykybCrLnjymSRUATM8yogMwHb7PteVm1qJdrNQEAbdH+VoNTW8LPKV Oh4ATOkNYEBQ3ggoMVTiJLfxzvHMs6x0Cm3pzhebs8k4Qhblhd0oodArFsRcSAH3F4VgmYfyejS 2HFhszKLViVsjsGKmIA== X-Authority-Analysis: v=2.4 cv=Je6Ma0KV c=1 sm=1 tr=0 ts=6a0643f8 cx=c_pps a=HLyN3IcIa5EE8TELMZ618Q==:117 a=nkegbr1AwBRna+m8FBH0UQ==:17 a=IkcTkHD0fZMA:10 a=NGcC8JguVDcA:10 a=x7bEGLp0ZPQA:10 a=VkNPw1HP01LnGYTKEx00:22 a=Da8U98TiO7q1upZEImrf:22 a=BpGzv1V74M3SfeTrGa8v:22 a=H0jnwmGZIJSlLSF8bakA:9 a=QEXdDO2ut3YA:10 a=bTQJ7kPSJx9SKPbeHEYW:22 X-Proofpoint-GUID: 8GMVYGmz4rv08ONNC9P1jfTk1SJTc1oX X-Proofpoint-ORIG-GUID: 8GMVYGmz4rv08ONNC9P1jfTk1SJTc1oX X-Proofpoint-Virus-Version: vendor=nai engine=6900 definitions=11786 signatures=596817 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=10 lowpriorityscore=10 bulkscore=10 clxscore=1015 adultscore=0 suspectscore=0 malwarescore=0 phishscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2605130000 definitions=main-2605140216 Add block_write_begin_iocb() which threads the kiocb through to __filemap_get_folio() so that buffer_head-based I/O can use DONTCACHE behavior. When the iocb has IOCB_DONTCACHE set, FGP_DONTCACHE is passed to mark the folio for dropbehind. The existing block_write_begin() is preserved as a wrapper that passes a NULL iocb. Set BIO_COMPLETE_IN_TASK in submit_bh_wbc() when the folio has dropbehind set, so that buffer_head writeback completions get deferred to task context. Signed-off-by: Tal Zussman --- fs/buffer.c | 19 +++++++++++++++++-- include/linux/buffer_head.h | 3 +++ 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index b0b3792b1496..d0abaf44d782 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2138,14 +2138,19 @@ EXPORT_SYMBOL(block_commit_write); * * The filesystem needs to handle block truncation upon failure. */ -int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, +int block_write_begin_iocb(const struct kiocb *iocb, + struct address_space *mapping, loff_t pos, unsigned len, struct folio **foliop, get_block_t *get_block) { pgoff_t index = pos >> PAGE_SHIFT; + fgf_t fgp_flags = FGP_WRITEBEGIN; struct folio *folio; int status; - folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN, + if (iocb && iocb->ki_flags & IOCB_DONTCACHE) + fgp_flags |= FGP_DONTCACHE; + + folio = __filemap_get_folio(mapping, index, fgp_flags, mapping_gfp_mask(mapping)); if (IS_ERR(folio)) return PTR_ERR(folio); @@ -2160,6 +2165,13 @@ int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, *foliop = folio; return status; } + +int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, + struct folio **foliop, get_block_t *get_block) +{ + return block_write_begin_iocb(NULL, mapping, pos, len, foliop, + get_block); +} EXPORT_SYMBOL(block_write_begin); int block_write_end(loff_t pos, unsigned len, unsigned copied, @@ -2715,6 +2727,9 @@ static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh, bio = bio_alloc(bh->b_bdev, 1, opf, GFP_NOIO); + if (folio_test_dropbehind(bh->b_folio)) + bio_set_flag(bio, BIO_COMPLETE_IN_TASK); + if (IS_ENABLED(CONFIG_FS_ENCRYPTION)) buffer_set_crypto_ctx(bio, bh, GFP_NOIO); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index e4939e33b4b5..4ce50882d621 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -260,6 +260,9 @@ int block_read_full_folio(struct folio *, get_block_t *); bool block_is_partially_uptodate(struct folio *, size_t from, size_t count); int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, struct folio **foliop, get_block_t *get_block); +int block_write_begin_iocb(const struct kiocb *iocb, + struct address_space *mapping, loff_t pos, unsigned len, + struct folio **foliop, get_block_t *get_block); int __block_write_begin(struct folio *folio, loff_t pos, unsigned len, get_block_t *get_block); int block_write_end(loff_t pos, unsigned len, unsigned copied, struct folio *); -- 2.39.5