[PATCH 37/52] fuse: multiplex cached/direct_io/dax file operations

Vivek Goyal
2018-12-10T17:13:03Z

From: Miklos Szeredi <mszeredi@redhat.com>

---
fs/fuse/file.c | 91 ++++++++++++++++++++++++++++--------------------------
fs/splice.c | 3 +-
include/linux/fs.h | 2 ++
3 files changed, 52 insertions(+), 44 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1f172d372eeb..6421c94cef46 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -22,8 +22,6 @@
#include <linux/iomap.h>
#include <linux/interval_tree_generic.h>

-static const struct file_operations fuse_direct_io_file_operations;
-
INTERVAL_TREE_DEFINE(struct fuse_dax_mapping,
rb, __u64, __subtree_last,
START, LAST, static inline, fuse_dax_interval_tree);
@@ -381,8 +379,6 @@ void fuse_finish_open(struct inode *inode, struct file *file)
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = get_fuse_conn(inode);

- if (ff->open_flags & FOPEN_DIRECT_IO)
- file->f_op = &fuse_direct_io_file_operations;
if (!(ff->open_flags & FOPEN_KEEP_CACHE))
invalidate_inode_pages2(inode->i_mapping);
if (ff->open_flags & FOPEN_NONSEEKABLE)
@@ -1121,11 +1117,23 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
return err;
}

+
+static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to);
+static ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
+
static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
- struct inode *inode = iocb->ki_filp->f_mapping->host;
+ struct file *file = iocb->ki_filp;
+ struct fuse_file *ff = file->private_data;
+ struct inode *inode = file->f_mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);

+ if (ff->open_flags & FOPEN_DIRECT_IO)
+ return fuse_direct_read_iter(iocb, to);
+
+ if (IS_DAX(inode))
+ return fuse_dax_read_iter(iocb, to);
+
/*
* In auto invalidate mode, always update attributes on read.
* Otherwise, only update if we attempt to read past EOF (to ensure
@@ -1375,9 +1383,14 @@ static ssize_t fuse_perform_write(struct kiocb *iocb,
return res > 0 ? res : err;
}

+static ssize_t fuse_direct_write_iter(struct kiocb *iocb,
+ struct iov_iter *from);
+static ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
+
static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
+ struct fuse_file *ff = file->private_data;
struct address_space *mapping = file->f_mapping;
ssize_t written = 0;
ssize_t written_buffered = 0;
@@ -1385,6 +1398,11 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
ssize_t err;
loff_t endbyte = 0;

+ if (ff->open_flags & FOPEN_DIRECT_IO)
+ return fuse_direct_write_iter(iocb, from);
+ if (IS_DAX(inode))
+ return fuse_dax_write_iter(iocb, from);
+
if (get_fuse_conn(inode)->writeback_cache) {
/* Update size (EOF optimization) and mode (SUID clearing) */
err = fuse_update_attributes(mapping->host, file);
@@ -2517,8 +2535,20 @@ static const struct vm_operations_struct fuse_file_vm_ops = {
.page_mkwrite = fuse_page_mkwrite,
};

+static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma);
+static int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
+
static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
+ struct fuse_file *ff = file->private_data;
+
+ /* DAX mmap is superior to direct_io mmap */
+ if (IS_DAX(file_inode(file)))
+ return fuse_dax_mmap(file, vma);
+
+ if (ff->open_flags & FOPEN_DIRECT_IO)
+ return fuse_direct_mmap(file, vma);
+
if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
fuse_link_write_file(file);

@@ -2538,6 +2568,18 @@ static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
return generic_file_mmap(file, vma);
}

+static ssize_t fuse_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags)
+{
+ struct fuse_file *ff = in->private_data;
+
+ if (ff->open_flags & FOPEN_DIRECT_IO)
+ return default_file_splice_read(in, ppos, pipe, len, flags);
+ else
+ return generic_file_splice_read(in, ppos, pipe, len, flags);
+
+}
static int __fuse_dax_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
bool write)
{
@@ -3629,13 +3671,13 @@ static const struct file_operations fuse_file_operations = {
.read_iter = fuse_file_read_iter,
.write_iter = fuse_file_write_iter,
.mmap = fuse_file_mmap,
+ .splice_read = fuse_file_splice_read,
.open = fuse_open,
.flush = fuse_flush,
.release = fuse_release,
.fsync = fuse_fsync,
.lock = fuse_file_lock,
.flock = fuse_file_flock,
- .splice_read = generic_file_splice_read,
.unlocked_ioctl = fuse_file_ioctl,
.compat_ioctl = fuse_file_compat_ioctl,
.poll = fuse_file_poll,
@@ -3643,42 +3685,6 @@ static const struct file_operations fuse_file_operations = {
.copy_file_range = fuse_copy_file_range,
};

-static const struct file_operations fuse_direct_io_file_operations = {
- .llseek = fuse_file_llseek,
- .read_iter = fuse_direct_read_iter,
- .write_iter = fuse_direct_write_iter,
- .mmap = fuse_direct_mmap,
- .open = fuse_open,
- .flush = fuse_flush,
- .release = fuse_release,
- .fsync = fuse_fsync,
- .lock = fuse_file_lock,
- .flock = fuse_file_flock,
- .unlocked_ioctl = fuse_file_ioctl,
- .compat_ioctl = fuse_file_compat_ioctl,
- .poll = fuse_file_poll,
- .fallocate = fuse_file_fallocate,
- /* no splice_read */
-};
-
-static const struct file_operations fuse_dax_file_operations = {
- .llseek = fuse_file_llseek,
- .read_iter = fuse_dax_read_iter,
- .write_iter = fuse_dax_write_iter,
- .mmap = fuse_dax_mmap,
- .open = fuse_open,
- .flush = fuse_flush,
- .release = fuse_release,
- .fsync = fuse_fsync,
- .lock = fuse_file_lock,
- .flock = fuse_file_flock,
- .unlocked_ioctl = fuse_file_ioctl,
- .compat_ioctl = fuse_file_compat_ioctl,
- .poll = fuse_file_poll,
- .fallocate = fuse_file_fallocate,
- /* no splice_read */
-};
-
static const struct address_space_operations fuse_file_aops = {
.readpage = fuse_readpage,
.writepage = fuse_writepage,
@@ -3716,7 +3722,6 @@ void fuse_init_file_inode(struct inode *inode)

if (fc->dax_dev) {
inode->i_flags |= S_DAX;
- inode->i_fop = &fuse_dax_file_operations;
inode->i_data.a_ops = &fuse_dax_file_aops;
}
}
diff --git a/fs/splice.c b/fs/splice.c
index 3553f1956508..93cbb03a70b1 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -365,7 +365,7 @@ static ssize_t kernel_readv(struct file *file, const struct kvec *vec,
return res;
}

-static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
+ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
@@ -429,6 +429,7 @@ static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
iov_iter_advance(&to, copied); /* truncates and discards */
return res;
}
+EXPORT_SYMBOL(default_file_splice_read);

/*
* Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c95c0807471f..574e63b58a6f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3040,6 +3040,8 @@ extern void block_sync_page(struct page *page);
/* fs/splice.c */
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
struct pipe_inode_info *, size_t, unsigned int);
+extern ssize_t default_file_splice_read(struct file *, loff_t *,
+ struct pipe_inode_info *, size_t, unsigned int);
extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
struct file *, loff_t *, size_t, unsigned int);
extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
--
2.13.6