[Virtio-fs] [PATCH v7 2/7] fuse: make DAX mount option a tri-state
Jeffle Xu
jefflexu at linux.alibaba.com
Tue Nov 2 05:25:59 UTC 2021
We add 'always', 'never', and 'inode' (default). '-o dax' continues to
operate the same which is equivalent to 'always'.
The following behavior is consistent with that on ext4/xfs:
- The default behavior (when neither '-o dax' nor
'-o dax=always|never|inode' option is specified) is equal to 'inode'
mode, while 'dax=inode' won't be printed among the mount option list.
- The 'inode' mode is only advisory. It will silently fallback to
'never' mode if fuse server doesn't support that.
Also noted that by the time of this commit, 'inode' mode is actually
equal to 'always' mode, before the per inode 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 | 20 ++++++++++++++++++--
fs/fuse/inode.c | 10 +++++++---
fs/fuse/virtio_fs.c | 18 +++++++++++++++---
4 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index 8c187b04874e..91c8d146dbc4 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1284,11 +1284,14 @@ 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;
@@ -1335,6 +1338,10 @@ 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);
+ enum fuse_dax_mode dax_mode = fc->dax_mode;
+
+ if (dax_mode == FUSE_DAX_NEVER)
+ return false;
if (!fc->dax)
return false;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index f55f9f94b1a4..4f9c2358f343 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -480,6 +480,18 @@ struct fuse_dev {
struct list_head entry;
};
+enum fuse_dax_mode {
+ FUSE_DAX_NONE, /* default */
+ FUSE_DAX_ALWAYS, /* "-o dax=always" */
+ FUSE_DAX_NEVER, /* "-o dax=never" */
+ FUSE_DAX_INODE, /* "-o dax=inode" */
+};
+
+static inline bool fuse_is_inode_dax_mode(enum fuse_dax_mode mode)
+{
+ return mode == FUSE_DAX_INODE || mode == FUSE_DAX_NONE;
+}
+
struct fuse_fs_context {
int fd;
struct file *file;
@@ -497,7 +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;
@@ -802,6 +814,9 @@ struct fuse_conn {
struct list_head devices;
#ifdef CONFIG_FUSE_DAX
+ /* Dax mode */
+ enum fuse_dax_mode dax_mode;
+
/* Dax specific conn data, non-NULL if DAX is enabled */
struct fuse_conn_dax *dax;
#endif
@@ -1258,7 +1273,8 @@ 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 12d49a1914e8..15ce56f9cf11 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -734,8 +734,12 @@ 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;
@@ -1481,7 +1485,7 @@ 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 94fc874f5de7..e8c404946c63 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[] = {
+ {"always", FUSE_DAX_ALWAYS },
+ {"never", FUSE_DAX_NEVER },
+ {"inode", FUSE_DAX_INODE },
+ {}
+};
+
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 *fsc,
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;
@@ -1326,8 +1338,8 @@ 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 (!fs->dax_dev) {
+ if (ctx->dax_mode != FUSE_DAX_NEVER) {
+ if (ctx->dax_mode == FUSE_DAX_ALWAYS && !fs->dax_dev) {
err = -EINVAL;
pr_err("virtio-fs: dax can't be enabled as filesystem"
" device does not support it.\n");
--
2.27.0
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