{"id":2226017,"url":"http://patchwork.ozlabs.org/api/1.2/patches/2226017/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/patch/20260422021042.4157510-19-yi.zhang@huaweicloud.com/","project":{"id":8,"url":"http://patchwork.ozlabs.org/api/1.2/projects/8/?format=json","name":"Linux ext4 filesystem development","link_name":"linux-ext4","list_id":"linux-ext4.vger.kernel.org","list_email":"linux-ext4@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260422021042.4157510-19-yi.zhang@huaweicloud.com>","list_archive_url":null,"date":"2026-04-22T02:10:38","name":"[v3,18/22] ext4: introduce a mount option for iomap buffered I/O path","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"c93a22a97461df90a515b3e584768df0667391e8","submitter":{"id":85428,"url":"http://patchwork.ozlabs.org/api/1.2/people/85428/?format=json","name":"Zhang Yi","email":"yi.zhang@huaweicloud.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-ext4/patch/20260422021042.4157510-19-yi.zhang@huaweicloud.com/mbox/","series":[{"id":500911,"url":"http://patchwork.ozlabs.org/api/1.2/series/500911/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/list/?series=500911","date":"2026-04-22T02:10:23","name":"ext4: use iomap for regular file's buffered I/O path","version":3,"mbox":"http://patchwork.ozlabs.org/series/500911/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2226017/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2226017/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-ext4@vger.kernel.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","patchwork-incoming@ozlabs.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=2404:9400:2221:ea00::3; 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Introduce 'buffered_iomap'\nand 'nobuffered_iomap' mount options to enable and disable the iomap\nbuffered I/O path for regular files.\n\nSigned-off-by: Zhang Yi \n---\n fs/ext4/ext4.h | 1 +\n fs/ext4/inode.c | 2 ++\n fs/ext4/super.c | 7 +++++++\n 3 files changed, 10 insertions(+)","diff":"diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h\nindex 80d086d40990..60ba488b01c5 100644\n--- a/fs/ext4/ext4.h\n+++ b/fs/ext4/ext4.h\n@@ -1281,6 +1281,7 @@ struct ext4_inode_info {\n \t\t\t\t\t\t * scanning in mballoc\n \t\t\t\t\t\t */\n #define EXT4_MOUNT2_ABORT\t\t0x00000100 /* Abort filesystem */\n+#define EXT4_MOUNT2_BUFFERED_IOMAP\t0x00000200 /* Use iomap for buffered I/O */\n \n #define clear_opt(sb, opt)\t\tEXT4_SB(sb)->s_mount_opt &= \\\n \t\t\t\t\t\t~EXT4_MOUNT_##opt\ndiff --git a/fs/ext4/inode.c b/fs/ext4/inode.c\nindex 57b5708235cf..d2f7af7922d7 100644\n--- a/fs/ext4/inode.c\n+++ b/fs/ext4/inode.c\n@@ -5750,6 +5750,8 @@ void ext4_enable_buffered_iomap(struct inode *inode)\n {\n \tstruct super_block *sb = inode->i_sb;\n \n+\tif (!test_opt2(sb, BUFFERED_IOMAP))\n+\t\treturn;\n \tif (!S_ISREG(inode->i_mode))\n \t\treturn;\n \tif (ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))\ndiff --git a/fs/ext4/super.c b/fs/ext4/super.c\nindex 62bfe05a64bc..b2da4834b6bb 100644\n--- a/fs/ext4/super.c\n+++ b/fs/ext4/super.c\n@@ -1722,6 +1722,7 @@ enum {\n \tOpt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,\n \tOpt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,\n \tOpt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,\n+\tOpt_buffered_iomap, Opt_nobuffered_iomap,\n \tOpt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,\n #ifdef CONFIG_EXT4_DEBUG\n \tOpt_fc_debug_max_replay, Opt_fc_debug_force\n@@ -1860,6 +1861,8 @@ static const struct fs_parameter_spec ext4_param_specs[] = {\n \tfsparam_flag\t(\"no_prefetch_block_bitmaps\",\n \t\t\t\t\t\tOpt_no_prefetch_block_bitmaps),\n \tfsparam_s32\t(\"mb_optimize_scan\",\tOpt_mb_optimize_scan),\n+\tfsparam_flag\t(\"buffered_iomap\",\tOpt_buffered_iomap),\n+\tfsparam_flag\t(\"nobuffered_iomap\",\tOpt_nobuffered_iomap),\n \tfsparam_string\t(\"check\",\t\tOpt_removed),\t/* mount option from ext2/3 */\n \tfsparam_flag\t(\"nocheck\",\t\tOpt_removed),\t/* mount option from ext2/3 */\n \tfsparam_flag\t(\"reservation\",\t\tOpt_removed),\t/* mount option from ext2/3 */\n@@ -1953,6 +1956,10 @@ static const struct mount_opts {\n \t{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},\n \t{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,\n \t MOPT_SET},\n+\t{Opt_buffered_iomap, EXT4_MOUNT2_BUFFERED_IOMAP,\n+\t MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},\n+\t{Opt_nobuffered_iomap, EXT4_MOUNT2_BUFFERED_IOMAP,\n+\t MOPT_CLEAR | MOPT_2 | MOPT_EXT4_ONLY},\n #ifdef CONFIG_EXT4_DEBUG\n \t{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,\n \t MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},\n","prefixes":["v3","18/22"]}