changes since v2:
- modify fuse_show_options() accordingly to make it compatible with
new tri-state mount option (patch 2)
- extract FUSE protocol changes into one seperate patch (patch 3)
- FUSE server/client need to negotiate if they support per-file DAX
(patch 4)
- extract DONT_CACHE logic into patch 6/7
This patchset adds support of per-file DAX for virtiofs, which is
inspired by Ira Weiny's work on ext4[1] and xfs[2].
Any comment is welcome.
[1] commit 9cb20f94afcd ("fs/ext4: Make DAX mount option a tri-state")
[2] commit 02beb2686ff9 ("fs/xfs: Make DAX mount option a tri-state")
v2: https://www.spinics.net/lists/linux-fsdevel/msg199584.html
v1: https://www.spinics.net/lists/linux-virtualization/msg51008.html
Jeffle Xu (8):
fuse: add fuse_should_enable_dax() helper
fuse: Make DAX mount option a tri-state
fuse: support per-file DAX
fuse: negotiate if server/client supports per-file DAX
fuse: enable per-file DAX
fuse: mark inode DONT_CACHE when per-file DAX indication changes
fuse: support changing per-file DAX flag inside guest
fuse: show '-o dax=inode' option only when FUSE server supports
fs/fuse/dax.c | 32 ++++++++++++++++++++++++++++++--
fs/fuse/file.c | 4 ++--
fs/fuse/fuse_i.h | 22 ++++++++++++++++++----
fs/fuse/inode.c | 27 ++++++++++++++++++---------
fs/fuse/ioctl.c | 15 +++++++++++++--
fs/fuse/virtio_fs.c | 16 ++++++++++++++--
include/uapi/linux/fuse.h | 9 ++++++++-
7 files changed, 103 insertions(+), 22 deletions(-)
--
2.27.0
This is in prep for following per-file DAX checking.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
fs/fuse/dax.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index 0e5407f48e6a..c6f4e82e65f3 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1336,11 +1336,19 @@ static const struct address_space_operations
fuse_dax_file_aops = {
.invalidatepage = noop_invalidatepage,
};
-void fuse_dax_inode_init(struct inode *inode)
+static bool fuse_should_enable_dax(struct inode *inode)
{
struct fuse_conn *fc = get_fuse_conn(inode);
if (!fc->dax)
+ return false;
+
+ return true;
+}
+
+void fuse_dax_inode_init(struct inode *inode)
+{
+ if (!fuse_should_enable_dax(inode))
return;
inode->i_flags |= S_DAX;
--
2.27.0
We add 'always', 'never', and 'inode' (default). '-o
dax' continues to
operate the same which is equivalent to 'always'.
By the time this patch is applied, 'inode' mode is actually equal to
'always' mode, before the per-file DAX flag is introduced in the
following patch.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
fs/fuse/dax.c | 9 +++++++--
fs/fuse/fuse_i.h | 14 ++++++++++++--
fs/fuse/inode.c | 10 +++++++---
fs/fuse/virtio_fs.c | 16 ++++++++++++++--
4 files changed, 40 insertions(+), 9 deletions(-)
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index c6f4e82e65f3..fe4e9593a590 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1288,11 +1288,14 @@ static int fuse_dax_mem_range_init(struct fuse_conn_dax
*fcd)
return ret;
}
-int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev)
+int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode dax_mode,
+ struct dax_device *dax_dev)
{
struct fuse_conn_dax *fcd;
int err;
+ fc->dax_mode = dax_mode;
+
if (!dax_dev)
return 0;
@@ -1339,8 +1342,10 @@ static const struct address_space_operations
fuse_dax_file_aops = {
static bool fuse_should_enable_dax(struct inode *inode)
{
struct fuse_conn *fc = get_fuse_conn(inode);
+ unsigned int dax_mode = fc->dax_mode;
- if (!fc->dax)
+ /* If 'dax=always/inode', fc->dax couldn't be NULL */
+ if (dax_mode == FUSE_DAX_NEVER)
return false;
return true;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 07829ce78695..a23dd8d0c181 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -487,6 +487,12 @@ struct fuse_dev {
struct list_head entry;
};
+enum fuse_dax_mode {
+ FUSE_DAX_INODE,
+ FUSE_DAX_ALWAYS,
+ FUSE_DAX_NEVER,
+};
+
struct fuse_fs_context {
int fd;
unsigned int rootmode;
@@ -503,7 +509,7 @@ struct fuse_fs_context {
bool no_control:1;
bool no_force_umount:1;
bool legacy_opts_show:1;
- bool dax:1;
+ enum fuse_dax_mode dax_mode;
unsigned int max_read;
unsigned int blksize;
const char *subtype;
@@ -801,6 +807,9 @@ struct fuse_conn {
struct list_head devices;
#ifdef CONFIG_FUSE_DAX
+ /* dax mode: FUSE_DAX_* (always, never or per-file) */
+ enum fuse_dax_mode dax_mode;
+
/* Dax specific conn data, non-NULL if DAX is enabled */
struct fuse_conn_dax *dax;
#endif
@@ -1242,7 +1251,8 @@ ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct
iov_iter *to);
ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
-int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
+int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode,
+ struct dax_device *dax_dev);
void fuse_dax_conn_free(struct fuse_conn *fc);
bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
void fuse_dax_inode_init(struct inode *inode);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index b9beb39a4a18..0bc0d8af81e1 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -690,8 +690,12 @@ static int fuse_show_options(struct seq_file *m, struct
dentry *root)
seq_printf(m, ",blksize=%lu", sb->s_blocksize);
}
#ifdef CONFIG_FUSE_DAX
- if (fc->dax)
- seq_puts(m, ",dax");
+ if (fc->dax_mode == FUSE_DAX_ALWAYS)
+ seq_puts(m, ",dax=always");
+ else if (fc->dax_mode == FUSE_DAX_NEVER)
+ seq_puts(m, ",dax=never");
+ else if (fc->dax_mode == FUSE_DAX_INODE)
+ seq_puts(m, ",dax=inode");
#endif
return 0;
@@ -1434,7 +1438,7 @@ int fuse_fill_super_common(struct super_block *sb, struct
fuse_fs_context *ctx)
sb->s_subtype = ctx->subtype;
ctx->subtype = NULL;
if (IS_ENABLED(CONFIG_FUSE_DAX)) {
- err = fuse_dax_conn_alloc(fc, ctx->dax_dev);
+ err = fuse_dax_conn_alloc(fc, ctx->dax_mode, ctx->dax_dev);
if (err)
goto err;
}
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 8f52cdaa8445..0050132e2787 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -88,12 +88,21 @@ struct virtio_fs_req_work {
static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq,
struct fuse_req *req, bool in_flight);
+static const struct constant_table dax_param_enums[] = {
+ {"inode", FUSE_DAX_INODE },
+ {"always", FUSE_DAX_ALWAYS },
+ {"never", FUSE_DAX_NEVER },
+ {}
+};
+
enum {
OPT_DAX,
+ OPT_DAX_ENUM,
};
static const struct fs_parameter_spec virtio_fs_parameters[] = {
fsparam_flag("dax", OPT_DAX),
+ fsparam_enum("dax", OPT_DAX_ENUM, dax_param_enums),
{}
};
@@ -110,7 +119,10 @@ static int virtio_fs_parse_param(struct fs_context *fc,
switch (opt) {
case OPT_DAX:
- ctx->dax = 1;
+ ctx->dax_mode = FUSE_DAX_ALWAYS;
+ break;
+ case OPT_DAX_ENUM:
+ ctx->dax_mode = result.uint_32;
break;
default:
return -EINVAL;
@@ -1326,7 +1338,7 @@ static int virtio_fs_fill_super(struct super_block *sb,
struct fs_context *fsc)
/* virtiofs allocates and installs its own fuse devices */
ctx->fudptr = NULL;
- if (ctx->dax) {
+ if (ctx->dax_mode != FUSE_DAX_NEVER) {
if (!fs->dax_dev) {
err = -EINVAL;
pr_err("virtio-fs: dax can't be enabled as filesystem"
--
2.27.0
Expand the fuse protocol to support per-file DAX.
FUSE_PERFILE_DAX flag is added indicating if fuse server/client
supporting per-file DAX when sending or replying FUSE_INIT request.
Besides, FUSE_ATTR_DAX flag is added indicating if DAX shall be enabled
for corresponding file when replying FUSE_LOOKUP request.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
include/uapi/linux/fuse.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 36ed092227fa..15a1f5fc0797 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -184,6 +184,9 @@
*
* 7.34
* - add FUSE_SYNCFS
+ *
+ * 7.35
+ * - add FUSE_PERFILE_DAX, FUSE_ATTR_DAX
*/
#ifndef _LINUX_FUSE_H
@@ -219,7 +222,7 @@
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 34
+#define FUSE_KERNEL_MINOR_VERSION 35
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
@@ -336,6 +339,7 @@ struct fuse_file_lock {
* write/truncate sgid is killed only if file has group
* execute permission. (Same as Linux VFS behavior).
* FUSE_SETXATTR_EXT: Server supports extended struct fuse_setxattr_in
+ * FUSE_PERFILE_DAX: kernel supports per-file DAX
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -367,6 +371,7 @@ struct fuse_file_lock {
#define FUSE_SUBMOUNTS (1 << 27)
#define FUSE_HANDLE_KILLPRIV_V2 (1 << 28)
#define FUSE_SETXATTR_EXT (1 << 29)
+#define FUSE_PERFILE_DAX (1 << 30)
/**
* CUSE INIT request/reply flags
@@ -449,8 +454,10 @@ struct fuse_file_lock {
* fuse_attr flags
*
* FUSE_ATTR_SUBMOUNT: Object is a submount root
+ * FUSE_ATTR_DAX: Enable DAX for this file in per-file DAX mode
*/
#define FUSE_ATTR_SUBMOUNT (1 << 0)
+#define FUSE_ATTR_DAX (1 << 1)
/**
* Open flags
--
2.27.0
Jeffle Xu
2021-Aug-04 07:06 UTC
[PATCH v3 4/8] fuse: negotiate if server/client supports per-file DAX
Among the FUSE_INIT phase, server/client shall negotiate if supporting
per-file DAX.
Requirements for server:
- capable of handling SETFLAGS/FSSETXATTR ioctl and storing
FS_DAX_FL/FS_XFLAG_DAX persistently.
- set FUSE_ATTR_DAX if the file capable of per-file DAX when replying
FUSE_LOOKUP request accordingly.
Requirements for client:
- capable of handling per-file DAX when receiving FUSE_ATTR_DAX.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
fs/fuse/fuse_i.h | 3 +++
fs/fuse/inode.c | 12 +++++++-----
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index a23dd8d0c181..0b21e76a379a 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -770,6 +770,9 @@ struct fuse_conn {
/* Propagate syncfs() to server */
unsigned int sync_fs:1;
+ /* Does the filesystem support per-file DAX? */
+ unsigned int perfile_dax:1;
+
/** The number of requests waiting for completion */
atomic_t num_waiting;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 0bc0d8af81e1..d59aea41d70d 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1087,10 +1087,12 @@ static void process_init_reply(struct fuse_mount *fm,
struct fuse_args *args,
min_t(unsigned int, fc->max_pages_limit,
max_t(unsigned int, arg->max_pages, 1));
}
- if (IS_ENABLED(CONFIG_FUSE_DAX) &&
- arg->flags & FUSE_MAP_ALIGNMENT &&
- !fuse_dax_check_alignment(fc, arg->map_alignment)) {
- ok = false;
+ if (IS_ENABLED(CONFIG_FUSE_DAX)) {
+ if (arg->flags & FUSE_MAP_ALIGNMENT &&
+ !fuse_dax_check_alignment(fc, arg->map_alignment))
+ ok = false;
+ if (arg->flags & FUSE_PERFILE_DAX)
+ fc->perfile_dax = 1;
}
if (arg->flags & FUSE_HANDLE_KILLPRIV_V2) {
fc->handle_killpriv_v2 = 1;
@@ -1144,7 +1146,7 @@ void fuse_send_init(struct fuse_mount *fm)
FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT;
#ifdef CONFIG_FUSE_DAX
if (fm->fc->dax)
- ia->in.flags |= FUSE_MAP_ALIGNMENT;
+ ia->in.flags |= FUSE_MAP_ALIGNMENT | FUSE_PERFILE_DAX;
#endif
if (fm->fc->auto_submounts)
ia->in.flags |= FUSE_SUBMOUNTS;
--
2.27.0
Enable per-file DAX if fuse server advertises that the file supports
that.
Currently the state whether the file enables DAX or not is initialized
only when inode is instantiated.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
fs/fuse/dax.c | 12 ++++++++----
fs/fuse/file.c | 4 ++--
fs/fuse/fuse_i.h | 4 ++--
fs/fuse/inode.c | 2 +-
4 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index fe4e9593a590..30833f8d37dd 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1339,7 +1339,7 @@ static const struct address_space_operations
fuse_dax_file_aops = {
.invalidatepage = noop_invalidatepage,
};
-static bool fuse_should_enable_dax(struct inode *inode)
+static bool fuse_should_enable_dax(struct inode *inode, unsigned int flags)
{
struct fuse_conn *fc = get_fuse_conn(inode);
unsigned int dax_mode = fc->dax_mode;
@@ -1348,12 +1348,16 @@ static bool fuse_should_enable_dax(struct inode *inode)
if (dax_mode == FUSE_DAX_NEVER)
return false;
- return true;
+ if (dax_mode == FUSE_DAX_ALWAYS)
+ return true;
+
+ WARN_ON_ONCE(dax_mode != FUSE_DAX_INODE);
+ return fc->perfile_dax && (flags & FUSE_ATTR_DAX);
}
-void fuse_dax_inode_init(struct inode *inode)
+void fuse_dax_inode_init(struct inode *inode, unsigned int flags)
{
- if (!fuse_should_enable_dax(inode))
+ if (!fuse_should_enable_dax(inode, flags))
return;
inode->i_flags |= S_DAX;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 97f860cfc195..b494ff08f08c 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3142,7 +3142,7 @@ static const struct address_space_operations
fuse_file_aops = {
.write_end = fuse_write_end,
};
-void fuse_init_file_inode(struct inode *inode)
+void fuse_init_file_inode(struct inode *inode, unsigned int flags)
{
struct fuse_inode *fi = get_fuse_inode(inode);
@@ -3156,5 +3156,5 @@ void fuse_init_file_inode(struct inode *inode)
fi->writepages = RB_ROOT;
if (IS_ENABLED(CONFIG_FUSE_DAX))
- fuse_dax_inode_init(inode);
+ fuse_dax_inode_init(inode, flags);
}
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 0b21e76a379a..7b7b4c208af2 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1006,7 +1006,7 @@ int fuse_notify_poll_wakeup(struct fuse_conn *fc,
/**
* Initialize file operations on a regular file
*/
-void fuse_init_file_inode(struct inode *inode);
+void fuse_init_file_inode(struct inode *inode, unsigned int flags);
/**
* Initialize inode operations on regular files and special files
@@ -1258,7 +1258,7 @@ int fuse_dax_conn_alloc(struct fuse_conn *fc, enum
fuse_dax_mode mode,
struct dax_device *dax_dev);
void fuse_dax_conn_free(struct fuse_conn *fc);
bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
-void fuse_dax_inode_init(struct inode *inode);
+void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
void fuse_dax_inode_cleanup(struct inode *inode);
bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int
map_alignment);
void fuse_dax_cancel_work(struct fuse_conn *fc);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index d59aea41d70d..882c376f188b 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -281,7 +281,7 @@ static void fuse_init_inode(struct inode *inode, struct
fuse_attr *attr)
inode->i_ctime.tv_nsec = attr->ctimensec;
if (S_ISREG(inode->i_mode)) {
fuse_init_common(inode);
- fuse_init_file_inode(inode);
+ fuse_init_file_inode(inode, attr->flags);
} else if (S_ISDIR(inode->i_mode))
fuse_init_dir(inode);
else if (S_ISLNK(inode->i_mode))
--
2.27.0
Jeffle Xu
2021-Aug-04 07:06 UTC
[PATCH v3 6/8] fuse: mark inode DONT_CACHE when per-file DAX indication changes
When the per-file DAX indication changes while the file is still
*opened*, it is quite complicated and maybe fragile to dynamically
change the DAX state.
Hence mark the inode and corresponding dentries as DONE_CACHE once the
per-file DAX indication changes, so that the inode instance will be
evicted and freed as soon as possible once the file is closed and the
last reference to the inode is put. And then when the file gets reopened
next time, the inode will reflect the new DAX state.
In summary, when the per-file DAX indication changes for an *opened*
file, the state of the file won't be updated until this file is closed
and reopened later.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
fs/fuse/dax.c | 9 +++++++++
fs/fuse/fuse_i.h | 1 +
fs/fuse/inode.c | 3 +++
3 files changed, 13 insertions(+)
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index 30833f8d37dd..14bc5b9a0576 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1364,6 +1364,15 @@ void fuse_dax_inode_init(struct inode *inode, unsigned
int flags)
inode->i_data.a_ops = &fuse_dax_file_aops;
}
+void fuse_dax_dontcache(struct inode *inode, bool newdax)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ if (fc->dax_mode == FUSE_DAX_INODE &&
+ fc->perfile_dax && IS_DAX(inode) != newdax)
+ d_mark_dontcache(inode);
+}
+
bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment)
{
if (fc->dax && (map_alignment > FUSE_DAX_SHIFT)) {
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 7b7b4c208af2..56fe1c4d2136 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1260,6 +1260,7 @@ void fuse_dax_conn_free(struct fuse_conn *fc);
bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
void fuse_dax_inode_cleanup(struct inode *inode);
+void fuse_dax_dontcache(struct inode *inode, bool newdax);
bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int
map_alignment);
void fuse_dax_cancel_work(struct fuse_conn *fc);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 882c376f188b..9108d8ab39bc 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -269,6 +269,9 @@ void fuse_change_attributes(struct inode *inode, struct
fuse_attr *attr,
if (inval)
invalidate_inode_pages2(inode->i_mapping);
}
+
+ if (IS_ENABLED(CONFIG_FUSE_DAX))
+ fuse_dax_dontcache(inode, attr->flags & FUSE_ATTR_DAX);
}
static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
--
2.27.0
Jeffle Xu
2021-Aug-04 07:06 UTC
[PATCH v3 7/8] fuse: support changing per-file DAX flag inside guest
Fuse client can enable or disable per-file DAX inside kernel/guest by
chattr(1). Similarly the new state won't be updated until the file is
closed and reopened later.
Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
fs/fuse/ioctl.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c
index 546ea3d58fb4..a9ed53c5dbd1 100644
--- a/fs/fuse/ioctl.c
+++ b/fs/fuse/ioctl.c
@@ -469,8 +469,6 @@ int fuse_fileattr_set(struct user_namespace *mnt_userns,
if (fa->flags_valid) {
err = fuse_priv_ioctl(inode, ff, FS_IOC_SETFLAGS,
&flags, sizeof(flags));
- if (err)
- goto cleanup;
} else {
memset(&xfa, 0, sizeof(xfa));
xfa.fsx_xflags = fa->fsx_xflags;
@@ -483,6 +481,19 @@ int fuse_fileattr_set(struct user_namespace *mnt_userns,
&xfa, sizeof(xfa));
}
+ if (err)
+ goto cleanup;
+
+ if (IS_ENABLED(CONFIG_FUSE_DAX)) {
+ bool newdax;
+
+ if (fa->flags_valid)
+ newdax = flags & FS_DAX_FL;
+ else
+ newdax = fa->fsx_xflags & FS_XFLAG_DAX;
+ fuse_dax_dontcache(inode, newdax);
+ }
+
cleanup:
fuse_priv_ioctl_cleanup(inode, ff);
--
2.27.0
Jeffle Xu
2021-Aug-04 07:06 UTC
[PATCH v3 8/8] fuse: show '-o dax=inode' option only when FUSE server supports
Prior of this patch, the mount option will still show '-o dax=inode' when FUSE server advertises that it doesn't support per-file DAX. Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com> --- fs/fuse/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9108d8ab39bc..439f74a041fa 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -697,7 +697,7 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root) seq_puts(m, ",dax=always"); else if (fc->dax_mode == FUSE_DAX_NEVER) seq_puts(m, ",dax=never"); - else if (fc->dax_mode == FUSE_DAX_INODE) + else if ((fc->dax_mode == FUSE_DAX_INODE) && fc->perfile_dax) seq_puts(m, ",dax=inode"); #endif -- 2.27.0
As discussed with Vivek Goyal, I tried to make virtiofsd support
per-file DAX by checking if the file is marked with FS_DAX_FL attr. Thus
I need to implement .ioctl() method for passthrough_ll.c (because
FS_DAX_FL attr is get/set by FS_IOC_GETFLAGS/FS_IOC_SETFLAGS ioctl),
something like
```
static struct fuse_lowlevel_ops lo_oper = {
+ .ioctl = lo_ioctl,
+static void lo_ioctl(...)
+{
+ ret = ioctl(fd, FS_IOC_SETFLAGS, ...);
}
```
But unfortunately once virtiofsd calls ioctl() syscall, it directly
exits, and qemu also hangs with 'qemu-system-x86_64: Unexpected
end-of-file before all data were read'. I'm not sure if it's because
ioctl() is not permitted at all for virtiofsd or qemu. Many thanks if
someone familiar with virtualization could help.
The code repository of virtiofsd used is:
gitlab.com/virtio-fs/qemu.git virtio-fs-dev
Thus this patch set is still used for test only, marking files larger
than 1MB shall enable per-file DAX.
Jeffle Xu (3):
virtiofsd: expand fuse protocol to support per-file DAX
virtiofsd: support per-file DAX negotiation in FUSE_INIT
virtiofsd: support per-file DAX in FUSE_LOOKUP
include/standard-headers/linux/fuse.h | 2 ++
tools/virtiofsd/fuse_common.h | 5 +++++
tools/virtiofsd/fuse_lowlevel.c | 6 ++++++
tools/virtiofsd/passthrough_ll.c | 6 ++++++
4 files changed, 19 insertions(+)
--
2.27.0
I mentioned in virtiofsd PATCH v1 that virtiofsd exits once ioctl() is called. After depper investigation into this issue, I find that it is because ioctl() is blocked out the whitelist of seccomp of virtiofsd. To support ioctl, ioctl syscall shall be added into the whitelist (see patch 1). And this is the complete workable version for virtiofsd: - virtiofsd now supports FUSE_IOCTL now, though currently only FS_IOC_G[S]ETFLAGS/FS_IOC_FSG[S]ETXATTR are supported. - During FUSE_INIT, virtiofsd advertise support for per-file DAX only when the backend fs is ext4/xfs. - FS_IOC_SETFLAGS/FS_IOC_FSSETXATTR FUSE_IOCTL will be directed to host, so that FS_DAX_FL could be flushed to backed fs persistently. - During FUSE_LOOKUP, virtiofsd will decide DAX shall be enabled for current file according to if this file is marked with FS_DAX_FL in the backend fs. PS. In the current implementation, the kernel always advertise FUSE_PERFILE_DAX no matter whether it's mounted with '-o dax=inode' or not. It can be fixed in the next version, and I need more feedbacks so far. Any comment on this whole series is welcome. Jeffle Xu (4): virtiofsd: add .ioctl() support virtiofsd: expand fuse protocol to support per-file DAX virtiofsd: support per-file DAX negotiation in FUSE_INIT virtiofsd: support per-file DAX in FUSE_LOOKUP include/standard-headers/linux/fuse.h | 2 + tools/virtiofsd/fuse_common.h | 5 ++ tools/virtiofsd/fuse_lowlevel.c | 6 ++ tools/virtiofsd/passthrough_ll.c | 115 ++++++++++++++++++++++++++ tools/virtiofsd/passthrough_seccomp.c | 1 + 5 files changed, 129 insertions(+) -- 2.27.0
ping? Corresponding patches for virtiofsd are also included in this patch set. On 8/4/21 3:06 PM, Jeffle Xu wrote:> changes since v2: > - modify fuse_show_options() accordingly to make it compatible with > new tri-state mount option (patch 2) > - extract FUSE protocol changes into one seperate patch (patch 3) > - FUSE server/client need to negotiate if they support per-file DAX > (patch 4) > - extract DONT_CACHE logic into patch 6/7 > > > This patchset adds support of per-file DAX for virtiofs, which is > inspired by Ira Weiny's work on ext4[1] and xfs[2]. > > Any comment is welcome. > > [1] commit 9cb20f94afcd ("fs/ext4: Make DAX mount option a tri-state") > [2] commit 02beb2686ff9 ("fs/xfs: Make DAX mount option a tri-state") > > v2: https://www.spinics.net/lists/linux-fsdevel/msg199584.html > v1: https://www.spinics.net/lists/linux-virtualization/msg51008.html > > Jeffle Xu (8): > fuse: add fuse_should_enable_dax() helper > fuse: Make DAX mount option a tri-state > fuse: support per-file DAX > fuse: negotiate if server/client supports per-file DAX > fuse: enable per-file DAX > fuse: mark inode DONT_CACHE when per-file DAX indication changes > fuse: support changing per-file DAX flag inside guest > fuse: show '-o dax=inode' option only when FUSE server supports > > fs/fuse/dax.c | 32 ++++++++++++++++++++++++++++++-- > fs/fuse/file.c | 4 ++-- > fs/fuse/fuse_i.h | 22 ++++++++++++++++++---- > fs/fuse/inode.c | 27 ++++++++++++++++++--------- > fs/fuse/ioctl.c | 15 +++++++++++++-- > fs/fuse/virtio_fs.c | 16 ++++++++++++++-- > include/uapi/linux/fuse.h | 9 ++++++++- > 7 files changed, 103 insertions(+), 22 deletions(-) >-- Thanks, Jeffle