From: Darrick J. Wong <djwong@xxxxxxxxxx>
Add a new notification so that fuse servers can add extra block devices
to use with iomap.
Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
fs/fuse/fuse_i.h | 19 +++++++
fs/fuse/fuse_trace.h | 36 ++++++++++++++
include/uapi/linux/fuse.h | 8 +++
fs/fuse/dev.c | 23 +++++++++
fs/fuse/file_iomap.c | 119 ++++++++++++++++++++++++++++++++++++++++++++-
fs/fuse/inode.c | 9 +++
6 files changed, 211 insertions(+), 3 deletions(-)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index aa51f25856697d..4eb75ed90db300 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -619,6 +619,12 @@ struct fuse_sync_bucket {
struct rcu_head rcu;
};
+struct fuse_iomap {
+ /* array of file objects that reference block devices for iomap */
+ struct file **files;
+ unsigned int nr_files;
+};
+
/**
* A Fuse connection.
*
@@ -970,6 +976,10 @@ struct fuse_conn {
struct fuse_ring *ring;
#endif
+#ifdef CONFIG_FUSE_IOMAP
+ struct fuse_iomap iomap_conn;
+#endif
+
/** Only used if the connection opts into request timeouts */
struct {
/* Worker for checking if any requests have timed out */
@@ -1610,9 +1620,18 @@ static inline bool fuse_has_iomap(const struct inode *inode)
{
return get_fuse_conn_c(inode)->iomap;
}
+
+void fuse_iomap_init_reply(struct fuse_mount *fm);
+void fuse_iomap_conn_put(struct fuse_conn *fc);
+
+int fuse_iomap_add_device(struct fuse_conn *fc,
+ const struct fuse_iomap_add_device_out *outarg);
#else
# define fuse_iomap_enabled(...) (false)
# define fuse_has_iomap(...) (false)
+# define fuse_iomap_init_reply(...) ((void)0)
+# define fuse_iomap_conn_put(...) ((void)0)
+# define fuse_iomap_add_device(...) (-ENOSYS)
#endif
#endif /* _FS_FUSE_I_H */
diff --git a/fs/fuse/fuse_trace.h b/fs/fuse/fuse_trace.h
index f9a316c9788e06..e1a2e491d2581a 100644
--- a/fs/fuse/fuse_trace.h
+++ b/fs/fuse/fuse_trace.h
@@ -380,6 +380,42 @@ TRACE_EVENT(fuse_iomap_end_error,
__entry->pos, __entry->count, __entry->written,
__entry->error)
);
+
+TRACE_EVENT(fuse_iomap_dev_class,
+ TP_PROTO(const struct fuse_conn *fc, unsigned int idx,
+ const struct file *file),
+
+ TP_ARGS(fc, idx, file),
+
+ TP_STRUCT__entry(
+ __field(dev_t, connection)
+ __field(unsigned int, idx)
+ __field(dev_t, bdev)
+ ),
+
+ TP_fast_assign(
+ struct inode *inode = file_inode(file);
+
+ __entry->connection = fc->dev;
+ __entry->idx = idx;
+ if (S_ISBLK(inode->i_mode)) {
+ __entry->bdev = inode->i_rdev;
+ } else
+ __entry->bdev = 0;
+ ),
+
+ TP_printk("connection %u idx %u dev %u:%u",
+ __entry->connection,
+ __entry->idx,
+ MAJOR(__entry->bdev), MINOR(__entry->bdev))
+);
+#define DEFINE_FUSE_IOMAP_DEV_EVENT(name) \
+DEFINE_EVENT(fuse_iomap_dev_class, name, \
+ TP_PROTO(const struct fuse_conn *fc, unsigned int idx, \
+ const struct file *file), \
+ TP_ARGS(fc, idx, file))
+DEFINE_FUSE_IOMAP_DEV_EVENT(fuse_iomap_add_dev);
+DEFINE_FUSE_IOMAP_DEV_EVENT(fuse_iomap_remove_dev);
#endif /* CONFIG_FUSE_IOMAP */
#endif /* _TRACE_FUSE_H */
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index ce6c9960f2418f..ea8992e980a015 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -236,6 +236,7 @@
* 7.44
* - add FUSE_IOMAP and iomap_{begin,end,ioend} handlers for FIEMAP and
* SEEK_{DATA,HOLE} support
+ * - add FUSE_NOTIFY_ADD_IOMAP_DEVICE for multi-device filesystems
*/
#ifndef _LINUX_FUSE_H
@@ -681,6 +682,7 @@ enum fuse_notify_code {
FUSE_NOTIFY_RETRIEVE = 5,
FUSE_NOTIFY_DELETE = 6,
FUSE_NOTIFY_RESEND = 7,
+ FUSE_NOTIFY_ADD_IOMAP_DEVICE = 8,
FUSE_NOTIFY_CODE_MAX,
};
@@ -1371,4 +1373,10 @@ struct fuse_iomap_end_in {
uint32_t map_dev; /* device cookie * */
};
+struct fuse_iomap_add_device_out {
+ int32_t fd; /* fd of the open device to add */
+ uint32_t reserved; /* must be zero */
+ uint32_t *map_dev; /* location to receive device cookie */
+};
+
#endif /* _LINUX_FUSE_H */
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 6dcbaa218b7a16..9d7064ec170cf6 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1824,6 +1824,26 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
return err;
}
+static int fuse_notify_add_iomap_device(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_iomap_add_device_out outarg;
+ int err = -EINVAL;
+
+ if (size != sizeof(outarg))
+ goto err;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ goto err;
+ fuse_copy_finish(cs);
+
+ return fuse_iomap_add_device(fc, &outarg);
+err:
+ fuse_copy_finish(cs);
+ return err;
+}
+
struct fuse_retrieve_args {
struct fuse_args_pages ap;
struct fuse_notify_retrieve_in inarg;
@@ -2049,6 +2069,9 @@ static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
case FUSE_NOTIFY_RESEND:
return fuse_notify_resend(fc);
+ case FUSE_NOTIFY_ADD_IOMAP_DEVICE:
+ return fuse_notify_add_iomap_device(fc, size, cs);
+
default:
fuse_copy_finish(cs);
return -EINVAL;
diff --git a/fs/fuse/file_iomap.c b/fs/fuse/file_iomap.c
index dfa0c309803113..faefd29a273bf3 100644
--- a/fs/fuse/file_iomap.c
+++ b/fs/fuse/file_iomap.c
@@ -142,6 +142,26 @@ static inline int fuse_iomap_validate(const struct fuse_iomap_begin_out *outarg,
return 0;
}
+static inline struct block_device *fuse_iomap_bdev(struct fuse_mount *fm,
+ unsigned int idx)
+{
+ struct fuse_conn *fc = fm->fc;
+ struct file *file = NULL;
+
+ spin_lock(&fc->lock);
+ if (idx < fc->iomap_conn.nr_files)
+ file = fc->iomap_conn.files[idx];
+ spin_unlock(&fc->lock);
+
+ if (!file)
+ return NULL;
+
+ if (!S_ISBLK(file_inode(file)->i_mode))
+ return NULL;
+
+ return I_BDEV(file->f_mapping->host);
+}
+
static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t count,
unsigned opflags, struct iomap *iomap,
struct iomap *srcmap)
@@ -155,6 +175,7 @@ static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t count,
};
struct fuse_iomap_begin_out outarg = { };
struct fuse_mount *fm = get_fuse_mount(inode);
+ struct block_device *read_bdev;
FUSE_ARGS(args);
int err;
@@ -181,8 +202,18 @@ static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t count,
if (err)
return err;
+ read_bdev = fuse_iomap_bdev(fm, outarg.read_dev);
+ if (!read_bdev)
+ return -ENODEV;
+
if ((opflags & IOMAP_WRITE) &&
outarg.write_type != FUSE_IOMAP_TYPE_PURE_OVERWRITE) {
+ struct block_device *write_bdev =
+ fuse_iomap_bdev(fm, outarg.write_dev);
+
+ if (!write_bdev)
+ return -ENODEV;
+
/*
* For an out of place write, we must supply the write mapping
* via @iomap, and the read mapping via @srcmap.
@@ -192,14 +223,14 @@ static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t count,
iomap->length = outarg.length;
iomap->type = outarg.write_type;
iomap->flags = outarg.write_flags;
- iomap->bdev = inode->i_sb->s_bdev;
+ iomap->bdev = write_bdev;
srcmap->addr = outarg.read_addr;
srcmap->offset = outarg.offset;
srcmap->length = outarg.length;
srcmap->type = outarg.read_type;
srcmap->flags = outarg.read_flags;
- srcmap->bdev = inode->i_sb->s_bdev;
+ srcmap->bdev = read_bdev;
} else {
/*
* For everything else (reads, reporting, and pure overwrites),
@@ -211,7 +242,7 @@ static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t count,
iomap->length = outarg.length;
iomap->type = outarg.read_type;
iomap->flags = outarg.read_flags;
- iomap->bdev = inode->i_sb->s_bdev;
+ iomap->bdev = read_bdev;
}
return 0;
@@ -278,3 +309,85 @@ const struct iomap_ops fuse_iomap_ops = {
.iomap_begin = fuse_iomap_begin,
.iomap_end = fuse_iomap_end,
};
+
+void fuse_iomap_conn_put(struct fuse_conn *fc)
+{
+ unsigned int i;
+
+ for (i = 0; i < fc->iomap_conn.nr_files; i++) {
+ struct file *file = fc->iomap_conn.files[i];
+
+ trace_fuse_iomap_remove_dev(fc, i, file);
+
+ fc->iomap_conn.files[i] = NULL;
+ fput(file);
+ }
+
+ kfree(fc->iomap_conn.files);
+ fc->iomap_conn.nr_files = 0;
+}
+
+/* Add a bdev to the fuse connection, returns the index or a negative errno */
+static int __fuse_iomap_add_device(struct fuse_conn *fc, struct file *file)
+{
+ struct file **new_files;
+ int ret;
+
+ if (fc->iomap_conn.nr_files >= PAGE_SIZE / sizeof(unsigned int))
+ return -EMFILE;
+
+ new_files = krealloc_array(fc->iomap_conn.files,
+ fc->iomap_conn.nr_files + 1,
+ sizeof(struct file *),
+ GFP_KERNEL | __GFP_ZERO);
+ if (!new_files)
+ return -ENOMEM;
+
+ spin_lock(&fc->lock);
+ fc->iomap_conn.files = new_files;
+ fc->iomap_conn.files[fc->iomap_conn.nr_files] = get_file(file);
+ ret = fc->iomap_conn.nr_files++;
+ spin_unlock(&fc->lock);
+
+ trace_fuse_iomap_add_dev(fc, ret, file);
+
+ return ret;
+}
+
+void fuse_iomap_init_reply(struct fuse_mount *fm)
+{
+ struct fuse_conn *fc = fm->fc;
+ struct super_block *sb = fm->sb;
+
+ if (sb->s_bdev)
+ __fuse_iomap_add_device(fc, sb->s_bdev_file);
+}
+
+int fuse_iomap_add_device(struct fuse_conn *fc,
+ const struct fuse_iomap_add_device_out *outarg)
+{
+ struct file *file;
+ int ret;
+
+ if (!fc->iomap)
+ return -EINVAL;
+
+ if (outarg->reserved)
+ return -EINVAL;
+
+ CLASS(fd, somefd)(outarg->fd);
+ if (fd_empty(somefd))
+ return -EBADF;
+ file = fd_file(somefd);
+
+ if (!S_ISBLK(file_inode(file)->i_mode))
+ return -ENODEV;
+
+ down_read(&fc->killsb);
+ ret = __fuse_iomap_add_device(fc, file);
+ up_read(&fc->killsb);
+ if (ret < 0)
+ return ret;
+
+ return put_user(ret, outarg->map_dev);
+}
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 88730d26c9b5e2..84b7cd5ffe843b 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1010,6 +1010,8 @@ void fuse_conn_put(struct fuse_conn *fc)
struct fuse_iqueue *fiq = &fc->iq;
struct fuse_sync_bucket *bucket;
+ if (fc->iomap)
+ fuse_iomap_conn_put(fc);
if (IS_ENABLED(CONFIG_FUSE_DAX))
fuse_dax_conn_free(fc);
if (fc->timeout.req_timeout)
@@ -1449,6 +1451,9 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
init_server_timeout(fc, timeout);
+ if (fc->iomap)
+ fuse_iomap_init_reply(fm);
+
fm->sb->s_bdi->ra_pages =
min(fm->sb->s_bdi->ra_pages, ra_pages);
fc->minor = arg->minor;
@@ -1886,6 +1891,10 @@ int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
err_free_dax:
if (IS_ENABLED(CONFIG_FUSE_DAX))
fuse_dax_conn_free(fc);
+ /*
+ * No need to call fuse_iomap_conn_put here because we don't add
+ * devices until the init reply.
+ */
err:
return err;
}
