Commit e959b549 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Eric Van Hensbergen
Browse files

fs/9p: Add direct IO support in cached mode


Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent fa6ea161
......@@ -254,8 +254,9 @@ static int v9fs_launder_page(struct page *page)
* with an error.
*
*/
ssize_t v9fs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
loff_t pos, unsigned long nr_segs)
static ssize_t
v9fs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
loff_t pos, unsigned long nr_segs)
{
/*
* FIXME
......
......@@ -579,15 +579,124 @@ out_unlock:
return VM_FAULT_NOPAGE;
}
static ssize_t
v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
loff_t *offsetp)
{
loff_t size, offset;
struct inode *inode;
struct address_space *mapping;
offset = *offsetp;
mapping = filp->f_mapping;
inode = mapping->host;
if (!count)
return 0;
size = i_size_read(inode);
if (offset < size)
filemap_write_and_wait_range(mapping, offset,
offset + count - 1);
return v9fs_file_read(filp, udata, count, offsetp);
}
/**
* v9fs_cached_file_read - read from a file
* @filp: file pointer to read
* @udata: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
static ssize_t
v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
loff_t *offset)
{
if (filp->f_flags & O_DIRECT)
return v9fs_direct_read(filp, data, count, offset);
return do_sync_read(filp, data, count, offset);
}
static ssize_t
v9fs_direct_write(struct file *filp, const char __user * data,
size_t count, loff_t *offsetp)
{
loff_t offset;
ssize_t retval;
struct inode *inode;
struct address_space *mapping;
offset = *offsetp;
mapping = filp->f_mapping;
inode = mapping->host;
if (!count)
return 0;
mutex_lock(&inode->i_mutex);
retval = filemap_write_and_wait_range(mapping, offset,
offset + count - 1);
if (retval)
goto err_out;
/*
* After a write we want buffered reads to be sure to go to disk to get
* the new data. We invalidate clean cached page from the region we're
* about to write. We do this *before* the write so that if we fail
* here we fall back to buffered write
*/
if (mapping->nrpages) {
pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
pgoff_t pg_end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
retval = invalidate_inode_pages2_range(mapping,
pg_start, pg_end);
/*
* If a page can not be invalidated, fall back
* to buffered write.
*/
if (retval) {
if (retval == -EBUSY)
goto buff_write;
goto err_out;
}
}
retval = v9fs_file_write(filp, data, count, offsetp);
err_out:
mutex_unlock(&inode->i_mutex);
return retval;
buff_write:
mutex_unlock(&inode->i_mutex);
return do_sync_write(filp, data, count, offsetp);
}
/**
* v9fs_cached_file_write - write to a file
* @filp: file pointer to write
* @data: data buffer to write data from
* @count: size of buffer
* @offset: offset at which to write data
*
*/
static ssize_t
v9fs_cached_file_write(struct file *filp, const char __user * data,
size_t count, loff_t *offset)
{
if (filp->f_flags & O_DIRECT)
return v9fs_direct_write(filp, data, count, offset);
return do_sync_write(filp, data, count, offset);
}
static const struct vm_operations_struct v9fs_file_vm_ops = {
.fault = filemap_fault,
.page_mkwrite = v9fs_vm_page_mkwrite,
};
const struct file_operations v9fs_cached_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.read = v9fs_cached_file_read,
.write = v9fs_cached_file_write,
.aio_read = generic_file_aio_read,
.aio_write = generic_file_aio_write,
.open = v9fs_file_open,
......@@ -599,8 +708,8 @@ const struct file_operations v9fs_cached_file_operations = {
const struct file_operations v9fs_cached_file_operations_dotl = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.read = v9fs_cached_file_read,
.write = v9fs_cached_file_write,
.aio_read = generic_file_aio_read,
.aio_write = generic_file_aio_write,
.open = v9fs_file_open,
......
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