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From: "Darrick J. Wong" <djwong@kernel.org>
To: tytso@mit.edu
Cc: John@groves.net, bernd@bsbernd.com,
	linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
	miklos@szeredi.hu, joannelkoong@gmail.com, neal@gompa.dev
Subject: [PATCH 19/19] fuse2fs: enable atomic writes
Date: Wed, 20 Aug 2025 18:20:39 -0700	[thread overview]
Message-ID: <175573714074.21970.8939552485779174661.stgit@frogsfrogsfrogs> (raw)
In-Reply-To: <175573713645.21970.9783397720493472605.stgit@frogsfrogsfrogs>

From: Darrick J. Wong <djwong@kernel.org>

Advertise the single-fsblock atomic write capability that iomap can do.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
 misc/fuse2fs.c |   68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 misc/fuse4fs.c |   67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 133 insertions(+), 2 deletions(-)


diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index a00c32e9f2cae8..04bb96f3438f23 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -281,6 +281,9 @@ struct fuse2fs {
 	void (*old_alloc_stats)(ext2_filsys fs, blk64_t blk, int inuse);
 	void (*old_alloc_stats_range)(ext2_filsys fs, blk64_t blk, blk_t num,
 				      int inuse);
+#ifdef STATX_WRITE_ATOMIC
+	unsigned int awu_min, awu_max;
+#endif
 #endif
 	unsigned int blockmask;
 	unsigned long offset;
@@ -580,9 +583,21 @@ static inline int fuse2fs_iomap_enabled(const struct fuse2fs *ff)
 {
 	return ff->iomap_state >= IOMAP_ENABLED;
 }
+
+static inline int fuse2fs_iomap_can_hw_atomic(const struct fuse2fs *ff)
+{
+	return fuse2fs_iomap_enabled(ff) &&
+	       (ff->iomap_cap & FUSE_IOMAP_SUPPORT_ATOMIC) &&
+#ifdef STATX_WRITE_ATOMIC
+		ff->awu_min > 0 && ff->awu_min > 0;
+#else
+		0;
+#endif
+}
 #else
 # define fuse2fs_iomap_enabled(...)	(0)
 # define fuse2fs_iomap_enabled(...)	(0)
+# define fuse2fs_iomap_can_hw_atomic(...)	(0)
 #endif
 
 static inline void fuse2fs_dump_extents(struct fuse2fs *ff, ext2_ino_t ino,
@@ -1631,14 +1646,19 @@ static int op_getattr(const char *path, struct stat *statbuf
 static int op_getattr_iflags(const char *path, struct stat *statbuf,
 			     unsigned int *iflags, struct fuse_file_info *fi)
 {
+	struct fuse2fs *ff = fuse2fs_get();
 	int ret = op_getattr(path, statbuf, fi);
 
 	if (ret)
 		return ret;
 
-	if (fuse_fs_can_enable_iomap(statbuf))
+	if (fuse_fs_can_enable_iomap(statbuf)) {
 		*iflags |= FUSE_IFLAG_IOMAP;
 
+		if (fuse2fs_iomap_can_hw_atomic(ff))
+			*iflags |= FUSE_IFLAG_ATOMIC;
+	}
+
 	return 0;
 }
 #endif
@@ -1744,6 +1764,15 @@ static int fuse2fs_statx(struct fuse2fs *ff, ext2_ino_t ino, int statx_mask,
 
 	fuse2fs_statx_directio(ff, stx);
 
+#ifdef STATX_WRITE_ATOMIC
+	if (fuse_fs_can_enable_iomapx(stx) && fuse2fs_iomap_can_hw_atomic(ff)) {
+		stx->stx_mask |= STATX_WRITE_ATOMIC;
+		stx->stx_atomic_write_unit_min = ff->awu_min;
+		stx->stx_atomic_write_unit_max = ff->awu_max;
+		stx->stx_atomic_write_segments_max = 1;
+	}
+#endif
+
 	return 0;
 }
 
@@ -5868,6 +5897,9 @@ static int op_iomap_begin(const char *path, uint64_t nodeid, uint64_t attr_ino,
 		}
 	}
 
+	if (opflags & FUSE_IOMAP_OP_ATOMIC)
+		read->flags |= FUSE_IOMAP_F_ATOMIC_BIO;
+
 out_unlock:
 	fuse2fs_finish(ff, ret);
 	return ret;
@@ -6027,6 +6059,38 @@ static int fuse2fs_set_bdev_blocksize(struct fuse2fs *ff, int fd)
 	return EIO;
 }
 
+#ifdef STATX_WRITE_ATOMIC
+static void fuse2fs_configure_atomic_write(struct fuse2fs *ff, int bdev_fd)
+{
+	struct statx devx;
+	unsigned int awu_min, awu_max;
+	int ret;
+
+	if (!ext2fs_has_feature_extents(ff->fs->super))
+		return;
+
+	ret = statx(bdev_fd, "", AT_EMPTY_PATH, STATX_WRITE_ATOMIC, &devx);
+	if (ret)
+		return;
+	if (!(devx.stx_mask & STATX_WRITE_ATOMIC))
+		return;
+
+	awu_min = max(ff->fs->blocksize, devx.stx_atomic_write_unit_min);
+	awu_max = min(ff->fs->blocksize, devx.stx_atomic_write_unit_max);
+	if (awu_min > awu_max)
+		return;
+
+	log_printf(ff, "%s awu_min: %u, awu_max: %u\n",
+		   _("Supports (experimental) DIO atomic writes"),
+		   awu_min, awu_max);
+
+	ff->awu_min = awu_min;
+	ff->awu_max = awu_max;
+}
+#else
+# define fuse2fs_configure_atomic_write(...)	((void)0)
+#endif
+
 static int fuse2fs_iomap_config_devices(struct fuse2fs *ff)
 {
 	errcode_t err;
@@ -6051,6 +6115,8 @@ static int fuse2fs_iomap_config_devices(struct fuse2fs *ff)
 	dbg_printf(ff, "%s: registered iomap dev fd=%d iomap_dev=%u\n",
 		   __func__, fd, ff->iomap_dev);
 
+	fuse2fs_configure_atomic_write(ff, fd);
+
 	ff->iomap_dev = ret;
 	return 0;
 }
diff --git a/misc/fuse4fs.c b/misc/fuse4fs.c
index b45f92a1cdbe25..43fc21149ba564 100644
--- a/misc/fuse4fs.c
+++ b/misc/fuse4fs.c
@@ -277,6 +277,9 @@ struct fuse4fs {
 	void (*old_alloc_stats)(ext2_filsys fs, blk64_t blk, int inuse);
 	void (*old_alloc_stats_range)(ext2_filsys fs, blk64_t blk, blk_t num,
 				      int inuse);
+#ifdef STATX_WRITE_ATOMIC
+	unsigned int awu_min, awu_max;
+#endif
 #endif
 	unsigned int blockmask;
 	unsigned long offset;
@@ -735,8 +738,20 @@ static inline int fuse4fs_iomap_enabled(const struct fuse4fs *ff)
 {
 	return ff->iomap_state >= IOMAP_ENABLED;
 }
+
+static inline int fuse4fs_iomap_can_hw_atomic(const struct fuse4fs *ff)
+{
+	return fuse4fs_iomap_enabled(ff) &&
+	       (ff->iomap_cap & FUSE_IOMAP_SUPPORT_ATOMIC) &&
+#ifdef STATX_WRITE_ATOMIC
+		ff->awu_min > 0 && ff->awu_min > 0;
+#else
+		0;
+#endif
+}
 #else
 # define fuse4fs_iomap_enabled(...)	(0)
+# define fuse4fs_iomap_can_hw_atomic(...)	(0)
 #endif
 
 static inline void fuse4fs_dump_extents(struct fuse4fs *ff, ext2_ino_t ino,
@@ -1737,8 +1752,12 @@ static int fuse4fs_stat_inode(struct fuse4fs *ff, ext2_ino_t ino,
 
 	fstat->iflags = 0;
 #ifdef HAVE_FUSE_IOMAP
-	if (fuse4fs_iomap_enabled(ff))
+	if (fuse4fs_iomap_enabled(ff)) {
 		fstat->iflags |= FUSE_IFLAG_IOMAP;
+
+		if (fuse4fs_iomap_can_hw_atomic(ff))
+			fstat->iflags |= FUSE_IFLAG_ATOMIC;
+	}
 #endif
 
 	return 0;
@@ -1913,6 +1932,15 @@ static int fuse4fs_statx(struct fuse4fs *ff, ext2_ino_t ino, int statx_mask,
 
 	fuse4fs_statx_directio(ff, stx);
 
+#ifdef STATX_WRITE_ATOMIC
+	if (fuse4fs_iomap_can_hw_atomic(ff)) {
+		stx->stx_mask |= STATX_WRITE_ATOMIC;
+		stx->stx_atomic_write_unit_min = ff->awu_min;
+		stx->stx_atomic_write_unit_max = ff->awu_max;
+		stx->stx_atomic_write_segments_max = 1;
+	}
+#endif
+
 	return 0;
 }
 
@@ -6193,6 +6221,9 @@ static void op_iomap_begin(fuse_req_t req, fuse_ino_t fino, uint64_t dontcare,
 		}
 	}
 
+	if (opflags & FUSE_IOMAP_OP_ATOMIC)
+		read.flags |= FUSE_IOMAP_F_ATOMIC_BIO;
+
 out_unlock:
 	fuse4fs_finish(ff, ret);
 	if (ret)
@@ -6355,6 +6386,38 @@ static int fuse4fs_set_bdev_blocksize(struct fuse4fs *ff, int fd)
 	return EIO;
 }
 
+#ifdef STATX_WRITE_ATOMIC
+static void fuse4fs_configure_atomic_write(struct fuse4fs *ff, int bdev_fd)
+{
+	struct statx devx;
+	unsigned int awu_min, awu_max;
+	int ret;
+
+	if (!ext2fs_has_feature_extents(ff->fs->super))
+		return;
+
+	ret = statx(bdev_fd, "", AT_EMPTY_PATH, STATX_WRITE_ATOMIC, &devx);
+	if (ret)
+		return;
+	if (!(devx.stx_mask & STATX_WRITE_ATOMIC))
+		return;
+
+	awu_min = max(ff->fs->blocksize, devx.stx_atomic_write_unit_min);
+	awu_max = min(ff->fs->blocksize, devx.stx_atomic_write_unit_max);
+	if (awu_min > awu_max)
+		return;
+
+	log_printf(ff, "%s awu_min: %u, awu_max: %u\n",
+		   _("Supports (experimental) DIO atomic writes"),
+		   awu_min, awu_max);
+
+	ff->awu_min = awu_min;
+	ff->awu_max = awu_max;
+}
+#else
+# define fuse4fs_configure_atomic_write(...)	((void)0)
+#endif
+
 static int fuse4fs_iomap_config_devices(struct fuse4fs *ff)
 {
 	errcode_t err;
@@ -6379,6 +6442,8 @@ static int fuse4fs_iomap_config_devices(struct fuse4fs *ff)
 	dbg_printf(ff, "%s: registered iomap dev fd=%d iomap_dev=%u\n",
 		   __func__, fd, ff->iomap_dev);
 
+	fuse4fs_configure_atomic_write(ff, fd);
+
 	ff->iomap_dev = ret;
 	return 0;
 }


  parent reply	other threads:[~2025-08-21  1:20 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-21  0:37 [RFC v4] fuse: use fs-iomap for better performance so we can containerize ext4 Darrick J. Wong
2025-08-21  0:49 ` [PATCHSET RFC v4 1/6] fuse4fs: fork a low level fuse server Darrick J. Wong
2025-08-21  1:08   ` [PATCH 01/20] fuse2fs: port fuse2fs to lowlevel libfuse API Darrick J. Wong
2025-08-21  1:08   ` [PATCH 02/20] fuse4fs: drop fuse 2.x support code Darrick J. Wong
2025-08-21  1:08   ` [PATCH 03/20] fuse4fs: namespace some helpers Darrick J. Wong
2025-08-21  1:08   ` [PATCH 04/20] fuse4fs: convert to low level API Darrick J. Wong
2025-08-21  1:09   ` [PATCH 05/20] libsupport: port the kernel list.h to libsupport Darrick J. Wong
2025-08-21  1:09   ` [PATCH 06/20] libsupport: add a cache Darrick J. Wong
2025-08-21  1:09   ` [PATCH 07/20] cache: disable debugging Darrick J. Wong
2025-08-21  1:09   ` [PATCH 08/20] cache: use modern list iterator macros Darrick J. Wong
2025-08-21  1:10   ` [PATCH 09/20] cache: embed struct cache in the owner Darrick J. Wong
2025-08-21  1:10   ` [PATCH 10/20] cache: pass cache pointer to callbacks Darrick J. Wong
2025-08-21  1:10   ` [PATCH 11/20] cache: pass a private data pointer through cache_walk Darrick J. Wong
2025-08-21  1:11   ` [PATCH 12/20] cache: add a helper to grab a new refcount for a cache_node Darrick J. Wong
2025-08-21  1:11   ` [PATCH 13/20] cache: return results of a cache flush Darrick J. Wong
2025-08-21  1:11   ` [PATCH 14/20] cache: add a "get only if incore" flag to cache_node_get Darrick J. Wong
2025-08-21  1:11   ` [PATCH 15/20] cache: support gradual expansion Darrick J. Wong
2025-08-21  1:12   ` [PATCH 16/20] cache: implement automatic shrinking Darrick J. Wong
2025-08-21  1:12   ` [PATCH 17/20] fuse4fs: add cache to track open files Darrick J. Wong
2025-08-21  1:12   ` [PATCH 18/20] fuse4fs: use the orphaned inode list Darrick J. Wong
2025-08-21  1:12   ` [PATCH 19/20] fuse4fs: implement FUSE_TMPFILE Darrick J. Wong
2025-08-21  1:13   ` [PATCH 20/20] fuse4fs: create incore reverse orphan list Darrick J. Wong
2025-08-21  0:49 ` [PATCHSET RFC v4 2/6] libext2fs: refactoring for fuse2fs iomap support Darrick J. Wong
2025-08-21  1:13   ` [PATCH 01/10] libext2fs: make it possible to extract the fd from an IO manager Darrick J. Wong
2025-08-21  1:13   ` [PATCH 02/10] libext2fs: always fsync the device when flushing the cache Darrick J. Wong
2025-08-21  1:13   ` [PATCH 03/10] libext2fs: always fsync the device when closing the unix IO manager Darrick J. Wong
2025-08-21  1:14   ` [PATCH 04/10] libext2fs: only fsync the unix fd if we wrote to the device Darrick J. Wong
2025-08-21  1:14   ` [PATCH 05/10] libext2fs: invalidate cached blocks when freeing them Darrick J. Wong
2025-08-21  1:14   ` [PATCH 06/10] libext2fs: only flush affected blocks in unix_write_byte Darrick J. Wong
2025-08-21  1:14   ` [PATCH 07/10] libext2fs: allow unix_write_byte when the write would be aligned Darrick J. Wong
2025-08-21  1:15   ` [PATCH 08/10] libext2fs: allow clients to ask to write full superblocks Darrick J. Wong
2025-08-21  1:15   ` [PATCH 09/10] libext2fs: allow callers to disallow I/O to file data blocks Darrick J. Wong
2025-08-21  1:15   ` [PATCH 10/10] libext2fs: add posix advisory locking to the unix IO manager Darrick J. Wong
2025-08-21  0:49 ` [PATCHSET RFC v4 3/6] fuse2fs: use fuse iomap data paths for better file I/O performance Darrick J. Wong
2025-08-21  1:15   ` [PATCH 01/19] fuse2fs: implement bare minimum iomap for file mapping reporting Darrick J. Wong
2025-08-21  1:16   ` [PATCH 02/19] fuse2fs: add iomap= mount option Darrick J. Wong
2025-08-21  1:16   ` [PATCH 03/19] fuse2fs: implement iomap configuration Darrick J. Wong
2025-08-21  1:16   ` [PATCH 04/19] fuse2fs: register block devices for use with iomap Darrick J. Wong
2025-08-21  1:17   ` [PATCH 05/19] fuse2fs: implement directio file reads Darrick J. Wong
2025-08-21  1:17   ` [PATCH 06/19] fuse2fs: add extent dump function for debugging Darrick J. Wong
2025-08-21  1:17   ` [PATCH 07/19] fuse2fs: implement direct write support Darrick J. Wong
2025-08-21  1:17   ` [PATCH 08/19] fuse2fs: turn on iomap for pagecache IO Darrick J. Wong
2025-08-21  1:18   ` [PATCH 09/19] fuse2fs: don't zero bytes in punch hole Darrick J. Wong
2025-08-21  1:18   ` [PATCH 10/19] fuse2fs: don't do file data block IO when iomap is enabled Darrick J. Wong
2025-08-21  1:18   ` [PATCH 11/19] fuse2fs: avoid fuseblk mode if fuse-iomap support is likely Darrick J. Wong
2025-08-21  1:18   ` [PATCH 12/19] fuse2fs: enable file IO to inline data files Darrick J. Wong
2025-08-21  1:19   ` [PATCH 13/19] fuse2fs: set iomap-related inode flags Darrick J. Wong
2025-08-21  1:19   ` [PATCH 14/19] fuse2fs: add strictatime/lazytime mount options Darrick J. Wong
2025-08-21  1:19   ` [PATCH 15/19] fuse2fs: configure block device block size Darrick J. Wong
2025-08-21  1:19   ` [PATCH 16/19] fuse4fs: don't use inode number translation when possible Darrick J. Wong
2025-08-21  1:20   ` [PATCH 17/19] fuse4fs: separate invalidation Darrick J. Wong
2025-08-21  1:20   ` [PATCH 18/19] fuse2fs: implement statx Darrick J. Wong
2025-08-21  1:20   ` Darrick J. Wong [this message]
2025-08-21  0:50 ` [PATCHSET RFC v4 4/6] fuse2fs: use fuse iomap data paths for better file I/O performance Darrick J. Wong
2025-08-21  1:20   ` [PATCH 1/2] fuse2fs: enable caching of iomaps Darrick J. Wong
2025-08-21  1:21   ` [PATCH 2/2] fuse2fs: be smarter about caching iomaps Darrick J. Wong
2025-08-21  0:50 ` [PATCHSET RFC v4 5/6] fuse2fs: handle timestamps and ACLs correctly when iomap is enabled Darrick J. Wong
2025-08-21  1:21   ` [PATCH 1/8] fuse2fs: skip permission checking on utimens " Darrick J. Wong
2025-08-21  1:21   ` [PATCH 2/8] fuse2fs: let the kernel tell us about acl/mode updates Darrick J. Wong
2025-08-21  1:21   ` [PATCH 3/8] fuse2fs: better debugging for file mode updates Darrick J. Wong
2025-08-21  1:22   ` [PATCH 4/8] fuse2fs: debug timestamp updates Darrick J. Wong
2025-08-21  1:22   ` [PATCH 5/8] fuse2fs: use coarse timestamps for iomap mode Darrick J. Wong
2025-08-21  1:22   ` [PATCH 6/8] fuse2fs: add tracing for retrieving timestamps Darrick J. Wong
2025-08-21  1:23   ` [PATCH 7/8] fuse2fs: enable syncfs Darrick J. Wong
2025-08-21  1:23   ` [PATCH 8/8] fuse2fs: skip the gdt write in op_destroy if syncfs is working Darrick J. Wong
2025-08-21  0:50 ` [PATCHSET RFC v4 6/6] fuse2fs: improve block and inode caching Darrick J. Wong
2025-08-21  1:23   ` [PATCH 1/6] libsupport: add caching IO manager Darrick J. Wong
2025-08-21  1:23   ` [PATCH 2/6] iocache: add the actual buffer cache Darrick J. Wong
2025-08-21  1:24   ` [PATCH 3/6] iocache: bump buffer mru priority every 50 accesses Darrick J. Wong
2025-08-21  1:24   ` [PATCH 4/6] fuse2fs: enable caching IO manager Darrick J. Wong
2025-08-21  1:24   ` [PATCH 5/6] fuse2fs: increase inode cache size Darrick J. Wong
2025-08-21  1:24   ` [PATCH 6/6] libext2fs: improve caching for inodes Darrick J. Wong

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