diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 9eb191b5c4de..a13793507d0b 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1009,6 +1009,20 @@ static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
return 0;
}
+static int fuse_copy_align(struct fuse_copy_state *cs, unsigned int align_size)
+{
+ /* Might happen if fuse-server does not use page aligned buffers */
+ if (cs->len < align_size) {
+ pr_info("Remaining cs->len (%u) too small for alignment (%u)\n",
+ cs->len, align_size);
+ return -EINVAL;
+ }
+ cs->len -= align_size;
+ cs->offset += align_size;
+
+ return 0;
+}
+
/* Copy request arguments to/from userspace buffer */
static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
unsigned argpages, struct fuse_arg *args,
@@ -1019,10 +1033,13 @@ static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
for (i = 0; !err && i < numargs; i++) {
struct fuse_arg *arg = &args[i];
- if (i == numargs - 1 && argpages)
+ if (i == numargs - 1 && argpages) {
err = fuse_copy_pages(cs, arg->size, zeroing);
- else
+ } else {
err = fuse_copy_one(cs, arg->value, arg->size);
+ if (!err && arg->align_size)
+ err = fuse_copy_align(cs, arg->align_size);
+ }
}
return err;
}
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index f39456c65ed7..0e1c540c6139 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1062,6 +1062,18 @@ static void fuse_write_args_fill(struct fuse_io_args *ia, struct fuse_file *ff,
args->in_args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
else
args->in_args[0].size = sizeof(ia->write.in);
+
+ if (ff->fm->fc->align_writes) {
+ /*
+ * add an extra alignment offset after the fuse header to
+ * the next page
+ */
+ args->in_args[0].align_size = PAGE_SIZE -
+ sizeof(struct fuse_in_header) -
+ sizeof(ia->write.in);
+ ia->write.in.align_size = args->in_args[0].align_size;
+ }
+
args->in_args[0].value = &ia->write.in;
args->in_args[1].size = count;
args->out_numargs = 1;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index f23919610313..cb15153c6785 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -275,13 +275,15 @@ struct fuse_file {
/** One input argument of a request */
struct fuse_in_arg {
- unsigned size;
+ unsigned int size;
+ unsigned int align_size;
const void *value;
};
/** One output argument of a request */
struct fuse_arg {
- unsigned size;
+ unsigned int size;
+ unsigned int align_size;
void *value;
};
@@ -860,6 +862,9 @@ struct fuse_conn {
/** Passthrough support for read/write IO */
unsigned int passthrough:1;
+ /** Should (write) data be page aligned? */
+ unsigned int align_writes:1;
+
/** Maximum stack depth for passthrough backing files */
int max_stack_depth;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 99e44ea7d875..e8b42859f553 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1331,6 +1331,9 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
}
if (flags & FUSE_NO_EXPORT_SUPPORT)
fm->sb->s_export_op = &fuse_export_fid_operations;
+
+ if (flags & FUSE_ALIGN_WRITES)
+ fc->align_writes = 1;
} else {
ra_pages = fc->max_read / PAGE_SIZE;
fc->no_lock = 1;
@@ -1378,7 +1381,7 @@ void fuse_send_init(struct fuse_mount *fm)
FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT |
FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP |
FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_ALLOW_MMAP |
- FUSE_NO_EXPORT_SUPPORT | FUSE_HAS_RESEND;
+ FUSE_NO_EXPORT_SUPPORT | FUSE_HAS_RESEND | FUSE_ALIGN_WRITES;
#ifdef CONFIG_FUSE_DAX
if (fm->fc->dax)
flags |= FUSE_MAP_ALIGNMENT;
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index d08b99d60f6f..4f5ddd7fe9b4 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -217,6 +217,11 @@
* - add backing_id to fuse_open_out, add FOPEN_PASSTHROUGH open flag
* - add FUSE_NO_EXPORT_SUPPORT init flag
* - add FUSE_NOTIFY_RESEND, add FUSE_HAS_RESEND init flag
+ *
+ * 7.41
+ * - add FUSE_ALIGN_WRITES init flag
+ * - make use of padding in struct fuse_write_in when
+ * initialization agrees on aligned writes
*/
#ifndef _LINUX_FUSE_H
@@ -252,7 +257,7 @@
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 40
+#define FUSE_KERNEL_MINOR_VERSION 41
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
@@ -421,6 +426,8 @@ struct fuse_file_lock {
* FUSE_NO_EXPORT_SUPPORT: explicitly disable export support
* FUSE_HAS_RESEND: kernel supports resending pending requests, and the high bit
* of the request ID indicates resend requests
+ * FUSE_ALIGN_WRITES: For opcode FUSE_WRITE, data follow the headers with a
+ * page aligned offset
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -463,6 +470,7 @@ struct fuse_file_lock {
#define FUSE_PASSTHROUGH (1ULL << 37)
#define FUSE_NO_EXPORT_SUPPORT (1ULL << 38)
#define FUSE_HAS_RESEND (1ULL << 39)
+#define FUSE_ALIGN_WRITES (1ULL << 40)
/* Obsolete alias for FUSE_DIRECT_IO_ALLOW_MMAP */
#define FUSE_DIRECT_IO_RELAX FUSE_DIRECT_IO_ALLOW_MMAP
@@ -496,6 +504,7 @@ struct fuse_file_lock {
* FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
* FUSE_WRITE_LOCKOWNER: lock_owner field is valid
* FUSE_WRITE_KILL_SUIDGID: kill suid and sgid bits
+ * FUSE_WRITE_ALIGNED: Data are at an page size aligned offset
*/
#define FUSE_WRITE_CACHE (1 << 0)
#define FUSE_WRITE_LOCKOWNER (1 << 1)
@@ -812,7 +821,7 @@ struct fuse_write_in {
uint32_t write_flags;
uint64_t lock_owner;
uint32_t flags;
- uint32_t padding;
+ uint32_t align_size; /* extra alignment offset to the next page */
};
struct fuse_write_out {
--
2.43.0
