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Wong" , Carlos Maiolino , Alexander Viro , Jan Kara Cc: Christoph Hellwig , 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, Tal Zussman X-Mailer: b4 0.14.3-dev-d7477 X-Developer-Signature: v=1; a=ed25519-sha256; t=1775689745; l=4833; i=tz2294@columbia.edu; s=20250528; h=from:subject:message-id; bh=vqYjVe4t0i/AiFArpSZ9mEXLlU4rnE2ZRBBMSnozEZ0=; b=TkXe1cDpr+0h2BcgYcYMwDXJ9OzGkB0Fsjl6RdOUbuhHuLsFpdpyPcESqIE4200vy+eNNs/A+ 038SUVLSqekBHFqdXjGfViao6J1wkhHyywZ87y01bw5yaC4bwnIIKLF X-Developer-Key: i=tz2294@columbia.edu; a=ed25519; pk=BIj5KdACscEOyAC0oIkeZqLB3L94fzBnDccEooxeM5Y= X-Authority-Analysis: v=2.4 cv=OdWoyBTY c=1 sm=1 tr=0 ts=69d6e016 cx=c_pps a=qKBjSQ1v91RyAK45QCPf5w==:117 a=mD05b5UW6KhLIDvowZ5dSQ==:17 a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=x7bEGLp0ZPQA:10 a=VkNPw1HP01LnGYTKEx00:22 a=Da8U98TiO7q1upZEImrf:22 a=BpGzv1V74M3SfeTrGa8v:22 a=KmSSIXLuV57r0wwE8Y4A:9 a=QEXdDO2ut3YA:10 a=NFOGd7dJGGMPyQGDc5-O:22 X-Proofpoint-ORIG-GUID: Qj_Md21WNIFv-hoIu6ByN5ydykx5vc_K X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDA4MDIxNCBTYWx0ZWRfXywg0VS3j5KG0 rDhZGk+QwOj0+Qs92DkpMfX8wPa+hO47syzNunEyXGKN05tkmTfqu/pkJSOLR2Gbwy0Ch1U1/pk 3E/h4EWSESizroTmb7X3ztEF+COx0/CUQSRln88S86jAU7vrtXh1KYDmIaC1smClIQ0GNIPZ0q1 +Wj0dJqJoReHxjN5IBI+2QL9dIa14pr5ouhuMqNFJCNlrnGNIuyj+PG/TIjvYcCCnIvBaMsMWA4 p01Usus6e7GcRGEELDagOljpQiWH53bUkuAv7sDHX6JIFLNUG8YbAlh0v84N1SGdUz9dkMvr0uN pPgl6HO6ulwqd1nWvOevWsbiI6zrx98l5Iol5d1om81PqTQ7ARYl+LsiOldhI/p2hcu0uUiUTTk Ub0pWxjGnx9L7EtvK0G7HjLYLYxItw562uCxzxej3JYst0ReEM6homWeqY1uJDG/4Nd37MCNrIH Fn8rIdayWKGl38dWPBQ== X-Proofpoint-GUID: Qj_Md21WNIFv-hoIu6ByN5ydykx5vc_K X-Proofpoint-Virus-Version: vendor=nai engine=6800 definitions=11753 signatures=596818 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 phishscore=0 priorityscore=1501 malwarescore=0 bulkscore=10 impostorscore=10 lowpriorityscore=10 adultscore=0 spamscore=0 clxscore=1015 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604010000 definitions=main-2604080214 X-Rspamd-Server: rspam12 X-Stat-Signature: do73ib1nmxr1qas8frakgaszy8hoyptg X-Rspamd-Queue-Id: 8A84220008 X-Rspam-User: X-HE-Tag: 1775689751-547879 X-HE-Meta: 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 FT4Ix1Vs Bl/3Az6wHsxJCUoNk9l1mx3Iaw3me5czeMfJ7NIMSbg60wvoDCslH5/T+tx6GDbpQ/9PCRyWWTN7PnRM+8B/dBTYGfNEyi6v3wFCJuEcEGffetJvmB0kjRnnWTMk20J9Nkq1RJYTUmqkhx//06ywwML9zujT+nxKPU0+zbyWBGa7e//l/EBNQgzQaBOUyUoqtnqZCIR3PJ/HlqbuP3yO0jd+gTyxKhkBwnVyLv054zONAhIFsOOr4PnFcled6krh/NgAncPf5HAZviGkitKM9fYANMZgATPWEuKRw+WHlXZSgO1jIYgAaSH8KMYem3JVmD4/WSNr0v0hdZFri2os31/vPfTx9Ttwov5qqikDZ9OodHgLdl7iQGxdqe0mdaACPOFYz4q3Gd5EBr5zCgobf4+R+qd/r8SCJbyYd4viUHt5KjfkTEoP7PRB3Pxn8wRgJ8vTeoYPH0RVr+ECxZEM/p2rCZVlvzlfCVrxEZMUu1AzOz5E= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Block device buffered reads and writes already pass through filemap_read() and iomap_file_buffered_write() respectively, both of which handle IOCB_DONTCACHE. Enable RWF_DONTCACHE for block device files by setting FOP_DONTCACHE in def_blk_fops. For CONFIG_BUFFER_HEAD=y paths, add block_write_begin_iocb() which threads the kiocb through so that buffer_head-based I/O can use DONTCACHE behavior. 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 so that buffer_head writeback completions get deferred to task context. CONFIG_BUFFER_HEAD=n paths are handled by the previously added iomap BIO_COMPLETE_IN_TASK support. This support is useful for databases that operate on raw block devices, among other userspace applications. Signed-off-by: Tal Zussman --- block/fops.c | 5 +++-- fs/buffer.c | 22 +++++++++++++++++++--- include/linux/buffer_head.h | 3 +++ 3 files changed, 25 insertions(+), 5 deletions(-) diff --git a/block/fops.c b/block/fops.c index 4d32785b31d9..d8165f6ba71c 100644 --- a/block/fops.c +++ b/block/fops.c @@ -505,7 +505,8 @@ static int blkdev_write_begin(const struct kiocb *iocb, unsigned len, struct folio **foliop, void **fsdata) { - return block_write_begin(mapping, pos, len, foliop, blkdev_get_block); + return block_write_begin_iocb(iocb, mapping, pos, len, foliop, + blkdev_get_block); } static int blkdev_write_end(const struct kiocb *iocb, @@ -967,7 +968,7 @@ const struct file_operations def_blk_fops = { .splice_write = iter_file_splice_write, .fallocate = blkdev_fallocate, .uring_cmd = blkdev_uring_cmd, - .fop_flags = FOP_BUFFER_RASYNC, + .fop_flags = FOP_BUFFER_RASYNC | FOP_DONTCACHE, }; static __init int blkdev_init(void) diff --git a/fs/buffer.c b/fs/buffer.c index ed724a902657..c60c0ad6cc35 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2239,14 +2239,19 @@ 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); @@ -2261,6 +2266,13 @@ 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, @@ -2589,7 +2601,8 @@ int cont_write_begin(const struct kiocb *iocb, struct address_space *mapping, (*bytes)++; } - return block_write_begin(mapping, pos, len, foliop, get_block); + return block_write_begin_iocb(iocb, mapping, pos, len, foliop, + get_block); } EXPORT_SYMBOL(cont_write_begin); @@ -2801,6 +2814,9 @@ 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); + fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO); bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index b16b88bfbc3e..ddf88ce290f2 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