Adds an io_uring interface for asynchronous encoded reads, using the
same interface as for the ioctl. To use this you would use an SQE opcode
of IORING_OP_URING_CMD, the cmd_op would be BTRFS_IOC_ENCODED_READ, and
addr would point to the userspace address of the
btrfs_ioctl_encoded_io_args struct. As with the ioctl, you need to have
CAP_SYS_ADMIN for this to work.
Signed-off-by: Mark Harmstone <maharmstone@xxxxxx>
---
fs/btrfs/btrfs_inode.h | 2 ++
fs/btrfs/file.c | 1 +
fs/btrfs/inode.c | 57 ++++++++++++++++++++++++++++++++++++----
fs/btrfs/ioctl.c | 59 ++++++++++++++++++++++++++++++++++++++++--
fs/btrfs/ioctl.h | 3 +++
5 files changed, 115 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index a5d786c6d7d4..62e5757d3ba2 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -620,6 +620,8 @@ struct btrfs_encoded_read_private {
struct btrfs_ioctl_encoded_io_args args;
struct file *file;
void __user *copy_out;
+ struct io_uring_cmd *cmd;
+ unsigned int issue_flags;
};
ssize_t btrfs_encoded_read(struct btrfs_encoded_read_private *priv);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 9914419f3b7d..2db76422d126 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3769,6 +3769,7 @@ const struct file_operations btrfs_file_operations = {
.compat_ioctl = btrfs_compat_ioctl,
#endif
.remap_file_range = btrfs_remap_file_range,
+ .uring_cmd = btrfs_uring_cmd,
.fop_flags = FOP_BUFFER_RASYNC | FOP_BUFFER_WASYNC,
};
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1bd4c74e8c51..e4458168c340 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -34,6 +34,7 @@
#include <linux/iomap.h>
#include <asm/unaligned.h>
#include <linux/fsverity.h>
+#include <linux/io_uring/cmd.h>
#include "misc.h"
#include "ctree.h"
#include "disk-io.h"
@@ -9078,7 +9079,7 @@ static ssize_t btrfs_encoded_read_inline(
return ret;
}
-static void btrfs_encoded_read_endio(struct btrfs_bio *bbio)
+static void btrfs_encoded_read_ioctl_endio(struct btrfs_bio *bbio)
{
struct btrfs_encoded_read_private *priv = bbio->private;
@@ -9098,6 +9099,47 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio)
bio_put(&bbio->bio);
}
+static inline struct btrfs_encoded_read_private *btrfs_uring_encoded_read_pdu(
+ struct io_uring_cmd *cmd)
+{
+ return *(struct btrfs_encoded_read_private **)cmd->pdu;
+}
+static void btrfs_finish_uring_encoded_read(struct io_uring_cmd *cmd,
+ unsigned int issue_flags)
+{
+ struct btrfs_encoded_read_private *priv;
+ ssize_t ret;
+
+ priv = btrfs_uring_encoded_read_pdu(cmd);
+ ret = btrfs_encoded_read_finish(priv, -EIOCBQUEUED);
+
+ io_uring_cmd_done(priv->cmd, ret, 0, priv->issue_flags);
+
+ kfree(priv);
+}
+
+static void btrfs_encoded_read_uring_endio(struct btrfs_bio *bbio)
+{
+ struct btrfs_encoded_read_private *priv = bbio->private;
+
+ if (bbio->bio.bi_status) {
+ /*
+ * The memory barrier implied by the atomic_dec_return() here
+ * pairs with the memory barrier implied by the
+ * atomic_dec_return() or io_wait_event() in
+ * btrfs_encoded_read_regular_fill_pages() to ensure that this
+ * write is observed before the load of status in
+ * btrfs_encoded_read_regular_fill_pages().
+ */
+ WRITE_ONCE(priv->status, bbio->bio.bi_status);
+ }
+ if (!atomic_dec_return(&priv->pending)) {
+ io_uring_cmd_complete_in_task(priv->cmd,
+ btrfs_finish_uring_encoded_read);
+ }
+ bio_put(&bbio->bio);
+}
+
static void _btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
u64 file_offset, u64 disk_bytenr,
u64 disk_io_size,
@@ -9106,11 +9148,16 @@ static void _btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
struct btrfs_fs_info *fs_info = inode->root->fs_info;
unsigned long i = 0;
struct btrfs_bio *bbio;
+ btrfs_bio_end_io_t cb;
- init_waitqueue_head(&priv->wait);
+ if (priv->cmd) {
+ cb = btrfs_encoded_read_uring_endio;
+ } else {
+ init_waitqueue_head(&priv->wait);
+ cb = btrfs_encoded_read_ioctl_endio;
+ }
- bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info,
- btrfs_encoded_read_endio, priv);
+ bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info, cb, priv);
bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;
bbio->inode = inode;
@@ -9122,7 +9169,7 @@ static void _btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
btrfs_submit_bio(bbio, 0);
bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info,
- btrfs_encoded_read_endio, priv);
+ cb, priv);
bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;
bbio->inode = inode;
continue;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c1886209933a..85a512a9ca64 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -29,6 +29,7 @@
#include <linux/fileattr.h>
#include <linux/fsverity.h>
#include <linux/sched/xacct.h>
+#include <linux/io_uring/cmd.h>
#include "ctree.h"
#include "disk-io.h"
#include "export.h"
@@ -4509,8 +4510,8 @@ static int _btrfs_ioctl_send(struct btrfs_inode *inode, void __user *argp, bool
return ret;
}
-static ssize_t btrfs_encoded_read_finish(struct btrfs_encoded_read_private *priv,
- ssize_t ret)
+ssize_t btrfs_encoded_read_finish(struct btrfs_encoded_read_private *priv,
+ ssize_t ret)
{
size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args,
flags);
@@ -4725,6 +4726,60 @@ static int btrfs_ioctl_encoded_write(struct file *file, void __user *argp, bool
return ret;
}
+static void btrfs_uring_encoded_read(struct io_uring_cmd *cmd,
+ unsigned int issue_flags)
+{
+ ssize_t ret;
+ void __user *argp = (void __user *)(uintptr_t)cmd->sqe->addr;
+ struct btrfs_encoded_read_private *priv;
+ bool compat = issue_flags & IO_URING_F_COMPAT;
+
+ priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ ret = -ENOMEM;
+ goto out_uring;
+ }
+
+ ret = btrfs_prepare_encoded_read(priv, cmd->file, compat, argp);
+ if (ret)
+ goto out_finish;
+
+ if (iov_iter_count(&priv->iter) == 0) {
+ ret = 0;
+ goto out_finish;
+ }
+
+ *(struct btrfs_encoded_read_private **)cmd->pdu = priv;
+ priv->cmd = cmd;
+ priv->issue_flags = issue_flags;
+ ret = btrfs_encoded_read(priv);
+
+ if (ret == -EIOCBQUEUED && atomic_dec_return(&priv->pending))
+ return;
+
+out_finish:
+ ret = btrfs_encoded_read_finish(priv, ret);
+ kfree(priv);
+
+out_uring:
+ io_uring_cmd_done(cmd, ret, 0, issue_flags);
+}
+
+int btrfs_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
+{
+ switch (cmd->cmd_op) {
+ case BTRFS_IOC_ENCODED_READ:
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ case BTRFS_IOC_ENCODED_READ_32:
+#endif
+ btrfs_uring_encoded_read(cmd, issue_flags);
+ return -EIOCBQUEUED;
+ }
+
+ io_uring_cmd_done(cmd, -EINVAL, 0, issue_flags);
+ return -EIOCBQUEUED;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 19cd26b0244a..9d1522de79d3 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -22,5 +22,8 @@ void btrfs_sync_inode_flags_to_i_flags(struct inode *inode);
int __pure btrfs_is_empty_uuid(const u8 *uuid);
void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_balance_args *bargs);
+int btrfs_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags);
+ssize_t btrfs_encoded_read_finish(struct btrfs_encoded_read_private *priv,
+ ssize_t ret);
#endif
--
2.44.2
