linux-ext4 - [PATCH 05/17] fuse2fs: implement directio file reads

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <176169817652.1429568.15117424981553294515.stgit@frogsfrogsfrogs>
Date: Tue, 28 Oct 2025 18:09:44 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: tytso@....edu
Cc: linux-fsdevel@...r.kernel.org, joannelkoong@...il.com, bernd@...ernd.com,
 neal@...pa.dev, miklos@...redi.hu, linux-ext4@...r.kernel.org
Subject: [PATCH 05/17] fuse2fs: implement directio file reads

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

Implement file reads via iomap.  Currently only directio is supported.

Signed-off-by: "Darrick J. Wong" <djwong@...nel.org>
---
 fuse4fs/fuse4fs.c |   14 +++++++++++++-
 misc/fuse2fs.c    |   14 +++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)


diff --git a/fuse4fs/fuse4fs.c b/fuse4fs/fuse4fs.c
index fba04feaa5770b..d8523ec8bbecc9 100644
--- a/fuse4fs/fuse4fs.c
+++ b/fuse4fs/fuse4fs.c
@@ -6138,7 +6138,19 @@ static int fuse4fs_iomap_begin_read(struct fuse4fs *ff, ext2_ino_t ino,
 				    uint64_t count, uint32_t opflags,
 				    struct fuse_file_iomap *read)
 {
-	return -ENOSYS;
+	if (!(opflags & FUSE_IOMAP_OP_DIRECT))
+		return -ENOSYS;
+
+	/* fall back to slow path for inline data reads */
+	if (inode->i_flags & EXT4_INLINE_DATA_FL)
+		return -ENOSYS;
+
+	if (inode->i_flags & EXT4_EXTENTS_FL)
+		return fuse4fs_iomap_begin_extent(ff, ino, inode, pos, count,
+						  opflags, read);
+
+	return fuse4fs_iomap_begin_indirect(ff, ino, inode, pos, count,
+					    opflags, read);
 }
 
 static int fuse4fs_iomap_begin_write(struct fuse4fs *ff, ext2_ino_t ino,
diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index 8738e0b78f45f2..f0bb19ef4c8b30 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -5584,7 +5584,19 @@ static int fuse2fs_iomap_begin_read(struct fuse2fs *ff, ext2_ino_t ino,
 				    uint64_t count, uint32_t opflags,
 				    struct fuse_file_iomap *read)
 {
-	return -ENOSYS;
+	if (!(opflags & FUSE_IOMAP_OP_DIRECT))
+		return -ENOSYS;
+
+	/* fall back to slow path for inline data reads */
+	if (inode->i_flags & EXT4_INLINE_DATA_FL)
+		return -ENOSYS;
+
+	if (inode->i_flags & EXT4_EXTENTS_FL)
+		return fuse2fs_iomap_begin_extent(ff, ino, inode, pos, count,
+						  opflags, read);
+
+	return fuse2fs_iomap_begin_indirect(ff, ino, inode, pos, count,
+					    opflags, read);
 }
 
 static int fuse2fs_iomap_begin_write(struct fuse2fs *ff, ext2_ino_t ino,