/*
* scfs_file_release
*/
static int scfs_file_release(struct inode *inode, struct file *file)
{
int ret;
SCFS_PRINT("f:%s calling fput with lower_file\n",
file->f_path.dentry->d_name.name);
if (file->f_flags & (O_RDWR | O_WRONLY)) {
CLEAR_WROPENED(SCFS_I(inode));
ret = scfs_write_meta(file);
if (ret)
return ret;
}
fput(SCFS_F(file)->lower_file);
kmem_cache_free(scfs_file_info_cache, SCFS_F(file));
profile_sub_kmcached(sizeof(struct scfs_file_info), SCFS_S(inode->i_sb));
return 0;
}
/**
* scfs_readpages
*
* Parameters:
* @file: upper file
* @*mapping: address_space struct for the file
* @*pages: list of pages to read in
* @nr_pages: number of pages to read in
*
* Return:
* SCFS_SUCCESS if success, otherwise if error
*
* Description:
* - Asynchronously read pages for readahead. A scaling number of background threads
* will read & decompress them in a slightly deferred but parallelized manner.
*/
static int
scfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct scfs_inode_info *sii = SCFS_I(file->f_mapping->host);
struct scfs_sb_info *sbi = SCFS_S(file->f_mapping->host->i_sb);
struct file *lower_file = NULL;
struct page *page;
struct scfs_cinfo cinfo;
loff_t i_size;
pgoff_t start, end;
int page_idx, page_idx_readahead = 1024, ret = 0;
int readahead_page = 0;
int prev_cbi = 0;
int prev_cluster = -1, cur_cluster = -1;
int cluster_idx = 0;
i_size = i_size_read(&sii->vfs_inode);
if (!i_size) {
SCFS_PRINT("file %s: i_size is zero, "
"flags 0x%x sii->clust_info_size %d\n",
file->f_path.dentry->d_name.name, sii->flags,
sii->cinfo_array_size);
return 0;
}
#ifdef SCFS_ASYNC_READ_PROFILE
atomic_add(nr_pages, &sbi->scfs_standby_readpage_count);
#endif
#ifdef SCFS_NOTIFY_RANDOM_READ
lower_file = scfs_lower_file(file);
if (!lower_file) {
SCFS_PRINT_ERROR("file %s: lower file is null!\n",
file->f_path.dentry->d_name.name);
return -EINVAL;
}
/* if the read request was random (enough), hint it to the lower file.
* scfs_sequential_page_number is the tunable threshold.
* filemap.c will later on refer to this FMODE_RANDOM flag.
*/
spin_lock(&lower_file->f_lock);
if (nr_pages > sbi->scfs_sequential_page_number)
lower_file->f_mode &= ~FMODE_RANDOM;
else
lower_file->f_mode |= FMODE_RANDOM;
spin_unlock(&lower_file->f_lock);
#endif
lower_file = scfs_lower_file(file);
page = list_entry(pages->prev, struct page, lru);
cluster_idx = page->index / (sii->cluster_size / PAGE_SIZE);
if (sii->compressed) {
mutex_lock(&sii->cinfo_mutex);
ret = get_cluster_info(file, cluster_idx, &cinfo);
mutex_unlock(&sii->cinfo_mutex);
if (ret) {
SCFS_PRINT_ERROR("err in get_cluster_info, ret : %d,"
"i_size %lld\n", ret, i_size);
return ret;
}
if (!cinfo.size || cinfo.size > sii->cluster_size) {
SCFS_PRINT_ERROR("file %s: cinfo is invalid, "
"clust %u cinfo.size %u\n",
file->f_path.dentry->d_name.name,
cluster_idx, cinfo.size);
return -EINVAL;
}
start = (pgoff_t)(cinfo.offset / PAGE_SIZE);
} else {
start = (pgoff_t)(cluster_idx * sii->cluster_size / PAGE_SIZE);
}
cluster_idx = (page->index + nr_pages - 1) / (sii->cluster_size / PAGE_SIZE);
if (sii->compressed) {
mutex_lock(&sii->cinfo_mutex);
ret = get_cluster_info(file, cluster_idx, &cinfo);
mutex_unlock(&sii->cinfo_mutex);
if (ret) {
SCFS_PRINT_ERROR("err in get_cluster_info, ret : %d,"
"i_size %lld\n", ret, i_size);
return ret;
}
if (!cinfo.size || cinfo.size > sii->cluster_size) {
SCFS_PRINT_ERROR("file %s: cinfo is invalid, "
"clust %u cinfo.size %u\n",
file->f_path.dentry->d_name.name,
cluster_idx, cinfo.size);
return -EINVAL;
}
end = (pgoff_t)((cinfo.offset + cinfo.size -1) / PAGE_SIZE);
} else {
end = (pgoff_t)(((cluster_idx + 1) * sii->cluster_size - 1) / PAGE_SIZE);
/* check upper inode size */
/* out of range? on compressed file, it is handled returning error,
which one is right? */
if (end > (i_size / PAGE_SIZE))
end = (i_size / PAGE_SIZE);
}
force_page_cache_readahead(lower_file->f_mapping, lower_file,
start, (unsigned long)(end - start +1));
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
page = list_entry(pages->prev, struct page, lru);
list_del(&page->lru);
if (PageReadahead(page))
page_idx_readahead = page_idx;
ret = add_to_page_cache_lru(page, mapping,
page->index, GFP_KERNEL);
if (ret) {
SCFS_PRINT("adding to page cache failed, "
"page %x page->idx %d ret %d\n",
page, page->index, ret);
page_cache_release(page);
continue;
}
/* memory buffer is full or synchronous read request -
call scfs_readpage to read now */
if (sbi->page_buffer_next_filling_index_smb ==
MAX_PAGE_BUFFER_SIZE_SMB || page_idx < page_idx_readahead) {
cur_cluster = PAGE_TO_CLUSTER_INDEX(page, sii);
if (prev_cluster == cur_cluster && prev_cbi > 0)
prev_cbi = _scfs_readpage(file, page, prev_cbi - 1);
else
prev_cbi = _scfs_readpage(file, page, -1);
prev_cluster = cur_cluster;
page_cache_release(page); /* refer line 701 */
} else {
spin_lock(&sbi->spinlock_smb);
/* Queue is not full so add the page into the queue.
Also, here we increase file->f_count to protect
the file structs from multi-threaded accesses */
atomic_long_inc(&SCFS_F(file)->lower_file->f_count);
atomic_long_inc(&file->f_count);
sbi->page_buffer_smb[sbi->page_buffer_next_filling_index_smb] = page;
sbi->file_buffer_smb[sbi->page_buffer_next_filling_index_smb++] = file;
/* check whether page buffer is full and set page buffer full if needed */
if (((sbi->page_buffer_next_filling_index_smb == MAX_PAGE_BUFFER_SIZE_SMB) &&
sbi->page_buffer_next_io_index_smb == 0) ||
(sbi->page_buffer_next_filling_index_smb ==
sbi->page_buffer_next_io_index_smb))
sbi->page_buffer_next_filling_index_smb = MAX_PAGE_BUFFER_SIZE_SMB;
else if (sbi->page_buffer_next_filling_index_smb == MAX_PAGE_BUFFER_SIZE_SMB)
sbi->page_buffer_next_filling_index_smb = 0;
spin_unlock(&sbi->spinlock_smb);
++readahead_page;
}
//page_cache_release(page);
}
if (readahead_page > 0)
wakeup_smb_thread(sbi);
SCFS_PRINT("<e>\n");
#ifdef SCFS_ASYNC_READ_PROFILE
atomic_sub(nr_pages, &sbi->scfs_standby_readpage_count);
#endif
return 0;
}
int smb_thread(void *data)
{
u32 length = 0, io_index, filling_index;
struct scfs_sb_info *sbi = (struct scfs_sb_info *)data;
struct page *page;
struct page *temp_page;
struct page *page_buffer[3] = {NULL, NULL, NULL};
struct file *file;
struct file *temp_file = NULL;
struct scfs_inode_info *sii;
int cluster_number = -1;
int page_buffer_count = 0;
int i;
int prev_cbi = 0;
set_freezable();
/* handle any queued-up read requests, or else go back to sleep */
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
spin_lock(&sbi->spinlock_smb);
/* calculate number of pages of page buffer */
io_index = sbi->page_buffer_next_io_index_smb;
filling_index = sbi->page_buffer_next_filling_index_smb;
if (filling_index == MAX_PAGE_BUFFER_SIZE_SMB) {
length = MAX_PAGE_BUFFER_SIZE_SMB;
sbi->page_buffer_next_filling_index_smb =
sbi->page_buffer_next_io_index_smb;
} else if (filling_index > io_index)
length = filling_index - io_index;
else if (filling_index < io_index)
length = (MAX_PAGE_BUFFER_SIZE_SMB - io_index) + filling_index;
else if (filling_index == io_index)
length = 0;
page_buffer_count = 0;
/* the requested page, as well as subsequent pages in the same cluster,
* will be serviced, in two separate readpage calls
*/
if (length > 0) {
__set_current_state(TASK_RUNNING);
page = sbi->page_buffer_smb[sbi->page_buffer_next_io_index_smb];
file = sbi->file_buffer_smb[sbi->page_buffer_next_io_index_smb];
sbi->page_buffer_next_io_index_smb++;
if (sbi->page_buffer_next_io_index_smb >= MAX_PAGE_BUFFER_SIZE_SMB)
sbi->page_buffer_next_io_index_smb = 0;
length--;
sii = SCFS_I(page->mapping->host);
cluster_number = PAGE_TO_CLUSTER_INDEX(page, sii);
while (length-- > 0) {
temp_page = sbi->page_buffer_smb[sbi->page_buffer_next_io_index_smb];
temp_file = sbi->file_buffer_smb[sbi->page_buffer_next_io_index_smb];
if ((temp_file == file) &&
(cluster_number == PAGE_TO_CLUSTER_INDEX(temp_page, sii))) {
page_buffer[page_buffer_count++] = temp_page;
sbi->page_buffer_next_io_index_smb++;
if (sbi->page_buffer_next_io_index_smb >=
MAX_PAGE_BUFFER_SIZE_SMB)
sbi->page_buffer_next_io_index_smb = 0;
} else
break;
}
spin_unlock(&sbi->spinlock_smb);
/* read first page */
prev_cbi = _scfs_readpage(file, page, -1);
fput(SCFS_F(file)->lower_file);
fput(file);
page_cache_release(page);
/* read related pages with cluster of first page*/
for (i = 0; i < page_buffer_count; i++) {
prev_cbi = _scfs_readpage(file, page_buffer[i], prev_cbi - 1);
fput(SCFS_F(file)->lower_file);
fput(file);
page_cache_release(page_buffer[i]);
}
} else {
//sbi->smb_task_status[xx] = 0;
spin_unlock(&sbi->spinlock_smb);
schedule();
//sbi->smb_task_status[xx] = 1;
}
}
return 0;
}
