int scfs_initialize_file(struct dentry *scfs_dentry, struct inode *scfs_inode)
{
struct scfs_inode_info *sii = SCFS_I(scfs_inode);
int ret = 0;
SCFS_DEBUG_START;
copy_mount_flags_to_inode_flags(scfs_inode, scfs_inode->i_sb);
if (S_ISDIR(scfs_inode->i_mode)) {
SCFS_PRINT_ERROR("it's a directory\n");
sii->flags &= ~(SCFS_DATA_COMPRESS);
goto out;
}
ret = scfs_get_lower_file(scfs_dentry, scfs_inode);
if (ret) {
SCFS_PRINT_ERROR("error in get_lower_file, ret : %d\n", ret);
goto out;
}
ret = scfs_make_header(scfs_dentry, scfs_inode);
if (ret)
SCFS_PRINT_ERROR("error in make header\n");
scfs_put_lower_file(scfs_inode);
out:
SCFS_DEBUG_END;
return ret;
}
static void scfs_destroy_inode(struct inode *inode)
{
struct scfs_sb_info *sbi = SCFS_S(inode->i_sb);
struct scfs_inode_info *sii = SCFS_I(inode);
if (sii->cinfo_array)
scfs_cinfo_free(sii, sii->cinfo_array);
if (!list_empty(&sii->cinfo_list)) {
SCFS_PRINT_ERROR("cinfo list is not empty!\n");
ASSERT(0);
}
if (sii->cluster_buffer.c_page) {
__free_pages(sii->cluster_buffer.c_page, SCFS_MEMPOOL_ORDER + 1);
sii->cluster_buffer.c_buffer = NULL;
sii->cluster_buffer.c_page = NULL;
}
if (sii->cluster_buffer.u_page) {
__free_pages(sii->cluster_buffer.u_page, SCFS_MEMPOOL_ORDER + 1);
sii->cluster_buffer.u_buffer = NULL;
sii->cluster_buffer.u_page = NULL;
atomic_sub(1, &sbi->current_file_count);
}
kmem_cache_free(scfs_inode_info_cache, sii);
profile_sub_kmcached(sizeof(struct scfs_inode_info), SCFS_S(inode->i_sb));
}
int scfs_initialize_file(struct dentry *scfs_dentry, struct inode *scfs_inode)
{
struct scfs_inode_info *sii = SCFS_I(scfs_inode);
int ret = 0;
copy_mount_flags_to_inode_flags(scfs_inode, scfs_inode->i_sb);
if (S_ISDIR(scfs_inode->i_mode)) {
SCFS_PRINT_ERROR("it's a directory\n");
sii->flags &= ~(SCFS_DATA_COMPRESSABLE);
goto out;
}
/* last parameter may be O_RDWR */
ret = scfs_get_lower_file(scfs_dentry, scfs_inode, EMPTY_FLAG);
if (ret) {
SCFS_PRINT_ERROR("error in get_lower_file, ret : %d\n", ret);
goto out;
}
ret = scfs_make_header(scfs_dentry, scfs_inode);
if (ret)
SCFS_PRINT_ERROR("error in make header\n");
scfs_put_lower_file(scfs_inode);
out:
return ret;
}
/* need to check parameters in calling vfs_write,
* especially data buf
*/
int scfs_make_header(struct dentry *scfs_dentry, struct inode *scfs_inode)
{
struct scfs_sb_info *sbi = SCFS_S(scfs_inode->i_sb);
struct file *lower_file = SCFS_I(scfs_inode)->lower_file;
struct comp_footer cf;
loff_t pos = 0;
int ret;
SCFS_DEBUG_START;
if (!lower_file) {
SCFS_PRINT_ERROR("lower_file is null\n");
return SCFS_ERR_IO;
}
cf.footer_size = sizeof(struct comp_footer);
cf.cluster_size = sbi->options.cluster_size;
cf.original_file_size = 0;
cf.comp_type = sbi->options.comp_type;
cf.magic = SCFS_MAGIC;
ret = scfs_lower_write(lower_file, (char *)&cf,
sizeof(struct comp_footer), &pos);
mark_inode_dirty_sync(scfs_inode); // why?
if (ret < 0) {
SCFS_PRINT_ERROR("error in writing header\n");
return ret;
}
ret = 0;
SCFS_DEBUG_END;
return ret;
}
int scfs_initialize_file(struct dentry *scfs_dentry, struct inode *scfs_inode)
{
struct scfs_inode_info *sii = SCFS_I(scfs_inode);
int ret = 0;
struct file *lower_file;
copy_mount_flags_to_inode_flags(scfs_inode, scfs_inode->i_sb);
if (S_ISDIR(scfs_inode->i_mode)) {
SCFS_PRINT_ERROR("it's a directory\n");
sii->flags &= ~(SCFS_DATA_COMPRESSABLE);
goto out;
}
ret = scfs_initialize_lower_file(scfs_dentry, &lower_file, O_RDWR);
if (ret) {
SCFS_PRINT_ERROR("error in get_lower_file, ret : %d\n", ret);
goto out;
}
ret = scfs_make_header(lower_file, scfs_inode);
if (ret)
SCFS_PRINT_ERROR("error in make header\n");
fput(lower_file);
out:
return ret;
}
/*
* 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;
}
static void scfs_evict_inode(struct inode *inode)
{
struct inode *lower_inode;
struct scfs_inode_info *sii = SCFS_I(inode);
truncate_inode_pages(&inode->i_data, 0);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
clear_inode(inode);
#else
end_writeback(inode);
#endif
/* to conserve memory, evicted inode will throw out the cluster info */
if (sii->cinfo_array) {
scfs_cinfo_free(sii, sii->cinfo_array);
sii->cinfo_array = NULL;
}
if (!list_empty(&sii->cinfo_list))
SCFS_PRINT_ERROR("cinfo list is not empty!\n");
lower_inode = scfs_lower_inode(inode);
scfs_set_lower_inode(inode, NULL);
iput(lower_inode);
}
static int scfs_open(struct inode *inode, struct file *file)
{
struct scfs_sb_info *sbi = SCFS_S(inode->i_sb);
struct scfs_inode_info *sii = SCFS_I(inode);
struct scfs_file_info *fi;
int ret = 0;
struct file *lower_file;
if (IS_WROPENED(sii)) {
SCFS_PRINT("This file is already opened with 'WRITE' flag\n");
return -EPERM;
}
fi = kmem_cache_zalloc(scfs_file_info_cache, GFP_KERNEL);
if (!fi)
return -ENOMEM;
profile_add_kmcached(sizeof(struct scfs_file_info), sbi);
file->private_data = fi;
mutex_lock(&sii->cinfo_mutex);
if (IS_INVALID_META(sii)) {
SCFS_PRINT("meta is invalid, so we should re-load it\n");
ret = scfs_reload_meta(file);
if (ret) {
SCFS_PRINT_ERROR("error in re-reading footer, err : %d\n", ret);
goto out;
}
} else if (sii->compressed && !sii->cinfo_array) {
/* 1st lower-open is for getting cinfo */
ret = scfs_initialize_lower_file(file->f_dentry, &lower_file, O_RDONLY);
if (ret) {
SCFS_PRINT_ERROR("err in get_lower_file %s\n",
file->f_dentry->d_name.name);
goto out;
}
scfs_set_lower_file(file, lower_file);
SCFS_PRINT("info size = %d \n", sii->cinfo_array_size);
ret = scfs_load_cinfo(sii, lower_file);
if (ret) {
SCFS_PRINT_ERROR("err in loading cinfo, ret : %d\n",
file->f_dentry->d_name.name);
fput(lower_file);
goto out;
}
fput(lower_file);
}
ret = scfs_initialize_lower_file(file->f_dentry, &lower_file, file->f_flags);
if (ret) {
SCFS_PRINT_ERROR("err in get_lower_file %s\n",
file->f_dentry->d_name.name);
goto out;
}
scfs_set_lower_file(file, lower_file);
out:
if (!ret) {
fsstack_copy_attr_all(inode, scfs_lower_inode(inode));
if (file->f_flags & (O_RDWR | O_WRONLY))
MAKE_WROPENED(sii);
} else {
scfs_set_lower_file(file, NULL);
kmem_cache_free(scfs_file_info_cache, file->private_data);
profile_sub_kmcached(sizeof(struct scfs_file_info), sbi);
sii->cinfo_array = NULL;
}
mutex_unlock(&sii->cinfo_mutex);
SCFS_PRINT("lower, dentry name : %s, count : %d, ret : %d\n",
file->f_dentry->d_name.name, file->f_dentry->d_count, ret);
return ret;
}
/**
* scfs_readpage
*
* Parameters:
* @file: upper file
* @page: upper page from SCFS inode mapping, data will be copied in here
*
* Return:
* SCFS_SUCCESS if success, otherwise if error
*
* Description:
* - Read in a page by reading a cluster from the file's lower file.
* (Reading in a cluster for just a single page read is inevitable, but this
* "amplified read" and decompressing overhead should be amortized when
* other pages in that same cluster is accessed later, and only incurs
* memcpy from the cached cluster buffer.)
* - Recently accessed clusters ("buffer_cache") are cached for later reads.
*/
static inline int _scfs_readpage(struct file *file, struct page *page, int pref_index)
{
struct scfs_inode_info *sii = SCFS_I(page->mapping->host);
struct scfs_sb_info *sbi = SCFS_S(page->mapping->host->i_sb);
struct scfs_cluster_buffer buffer = {NULL, NULL, NULL, NULL, 0};
int ret = 0, compressed = 0;
int alloc_membuffer = 1;
int allocated_index = -1;
int i;
char *virt;
SCFS_PRINT("f:%s i:%d c:0x%x u:0x%x\n",
file->f_path.dentry->d_name.name,
page->index, buffer.c_buffer, buffer.u_buffer);
ASSERT(sii->cluster_size <= SCFS_CLUSTER_SIZE_MAX);
#ifdef SCFS_ASYNC_READ_PROFILE
sbi->scfs_readpage_total_count++;
#endif
#if MAX_BUFFER_CACHE
/* search buffer_cache first in case the cluster is left cached */
if (pref_index >= 0 &&
sbi->buffer_cache[pref_index].inode_number == sii->vfs_inode.i_ino &&
sbi->buffer_cache[pref_index].cluster_number ==
PAGE_TO_CLUSTER_INDEX(page, sii) &&
atomic_read(&sbi->buffer_cache[pref_index].is_used) != 1) {
spin_lock(&sbi->buffer_cache_lock);
/* this pref_index is used for another page */
if (atomic_read(&sbi->buffer_cache[pref_index].is_used) == 1) {
spin_unlock(&sbi->buffer_cache_lock);
sbi->buffer_cache_reclaimed_before_used_count++;
goto pick_slot;
}
atomic_set(&sbi->buffer_cache[pref_index].is_used, 1);
spin_unlock(&sbi->buffer_cache_lock);
virt = kmap_atomic(page);
if (sbi->buffer_cache[pref_index].is_compressed)
memcpy(virt, page_address(sbi->buffer_cache[pref_index].u_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
else
memcpy(virt, page_address(sbi->buffer_cache[pref_index].c_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
atomic_set(&sbi->buffer_cache[pref_index].is_used, 0);
kunmap_atomic(virt);
SetPageUptodate(page);
unlock_page(page);
SCFS_PRINT("%s<h> %d\n",file->f_path.dentry->d_name.name, page->index);
return pref_index + 1;
} else if (pref_index >= 0) {
sbi->buffer_cache_reclaimed_before_used_count++;
goto pick_slot;
}
/* search buffer_cache first in case the cluster is left cached */
for (i = 0; i < MAX_BUFFER_CACHE; i++) {
if (sbi->buffer_cache[i].inode_number == sii->vfs_inode.i_ino &&
sbi->buffer_cache[i].cluster_number ==
PAGE_TO_CLUSTER_INDEX(page, sii) &&
atomic_read(&sbi->buffer_cache[i].is_used) != 1) {
spin_lock(&sbi->buffer_cache_lock);
if (atomic_read(&sbi->buffer_cache[i].is_used) == 1) {
spin_unlock(&sbi->buffer_cache_lock);
goto pick_slot;
}
atomic_set(&sbi->buffer_cache[i].is_used, 1);
spin_unlock(&sbi->buffer_cache_lock);
virt = kmap_atomic(page);
if (sbi->buffer_cache[i].is_compressed)
memcpy(virt, page_address(sbi->buffer_cache[i].u_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
else
memcpy(virt, page_address(sbi->buffer_cache[i].c_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
atomic_set(&sbi->buffer_cache[i].is_used, 0);
kunmap_atomic(virt);
SetPageUptodate(page);
unlock_page(page);
SCFS_PRINT("%s<h> %d\n",
file->f_path.dentry->d_name.name, page->index);
return i + 1;
}
}
pick_slot:
/* pick a slot in buffer_cache to use */
if (atomic_read(&sbi->buffer_cache[sbi->read_buffer_index].is_used) != 1) {
spin_lock(&sbi->buffer_cache_lock);
/* this index is used for another page */
if (atomic_read(&sbi->buffer_cache[sbi->read_buffer_index].is_used) == 1) {
spin_unlock(&sbi->buffer_cache_lock);
goto pick_slot_full;
}
atomic_set(&sbi->buffer_cache[sbi->read_buffer_index].is_used, 1);
allocated_index = sbi->read_buffer_index++;
if (sbi->read_buffer_index >= MAX_BUFFER_CACHE)
sbi->read_buffer_index = 0;
spin_unlock(&sbi->buffer_cache_lock);
buffer.c_page = sbi->buffer_cache[allocated_index].c_page;
buffer.u_page = sbi->buffer_cache[allocated_index].u_page;
sbi->buffer_cache[allocated_index].inode_number = sii->vfs_inode.i_ino;
sbi->buffer_cache[allocated_index].cluster_number =
PAGE_TO_CLUSTER_INDEX(page, sii);
alloc_membuffer = 0;
goto real_io;
}
pick_slot_full:
for (i = 0; i < MAX_BUFFER_CACHE; i++) {
if (atomic_read(&sbi->buffer_cache[i].is_used) != 1) {
spin_lock(&sbi->buffer_cache_lock);
/* this index is used for another page */
if (atomic_read(&sbi->buffer_cache[i].is_used) == 1) {
spin_unlock(&sbi->buffer_cache_lock);
continue;
}
atomic_set(&sbi->buffer_cache[i].is_used, 1);
sbi->read_buffer_index = i + 1;
if (sbi->read_buffer_index >= MAX_BUFFER_CACHE)
sbi->read_buffer_index = 0;
spin_unlock(&sbi->buffer_cache_lock);
buffer.c_page = sbi->buffer_cache[i].c_page;
buffer.u_page = sbi->buffer_cache[i].u_page;
sbi->buffer_cache[i].inode_number = sii->vfs_inode.i_ino;
sbi->buffer_cache[i].cluster_number =
PAGE_TO_CLUSTER_INDEX(page, sii);
allocated_index = i;
alloc_membuffer = 0;
break;
}
}
#endif
real_io:
#ifdef SCFS_ASYNC_READ_PROFILE
sbi->scfs_readpage_io_count++;
#endif
/* sanity check & prepare buffers for scfs_read_cluster */
if (alloc_membuffer == 1 && (buffer.c_page || buffer.c_buffer))
ASSERT(0);
if (!buffer.c_page)
buffer.c_page = scfs_alloc_mempool_buffer(sbi);
if (!buffer.c_page) {
SCFS_PRINT_ERROR("c_page malloc failed\n");
ret = -ENOMEM;
goto out;
}
if (!buffer.c_buffer)
buffer.c_buffer = page_address(buffer.c_page);
if (!buffer.c_buffer) {
SCFS_PRINT_ERROR("c_buffer malloc failed\n");
ret = -ENOMEM;
goto out;
}
if (!buffer.u_page)
buffer.u_page = scfs_alloc_mempool_buffer(sbi);
if (!buffer.u_page) {
SCFS_PRINT_ERROR("u_page malloc failed\n");
ret = -ENOMEM;
goto out;
}
if (!buffer.u_buffer)
buffer.u_buffer = page_address(buffer.u_page);
if (!buffer.u_buffer) {
SCFS_PRINT_ERROR("u_buffer malloc failed\n");
ret = -ENOMEM;
goto out;
}
/* read cluster from lower */
ret = scfs_read_cluster(file, page, buffer.c_buffer, &buffer.u_buffer, &compressed);
if (ret) {
if (ret == -ERANGE)
SCFS_PRINT_ERROR("file %s error on readpage, OOB. ret %x\n",
file->f_path.dentry->d_name.name, ret);
else
SCFS_PRINT_ERROR("read cluster failed, "
"file %s page->index %u ret %d\n",
file->f_path.dentry->d_name.name, page->index, ret);
goto out;
}
#if MAX_BUFFER_CACHE
/* don't need to spinlock, we have is_used=1 for this buffer */
if (alloc_membuffer != 1)
sbi->buffer_cache[allocated_index].is_compressed = compressed;
#endif
#ifdef SCFS_REMOVE_NO_COMPRESSED_UPPER_MEMCPY
/* fill page cache with the decompressed or original page */
if (compressed) {
virt = kmap_atomic(page);
memcpy(virt, page_address(buffer.u_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
kunmap_atomic(virt);
}
#else
/* fill page cache with the decompressed/original data */
virt = kmap_atomic(page);
if (compressed)
memcpy(virt, page_address(buffer.u_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
else
memcpy(virt, page_address(buffer.c_page) +
PGOFF_IN_CLUSTER(page, sii) * PAGE_SIZE, PAGE_SIZE);
kunmap_atomic(virt);
#endif
SetPageUptodate(page);
#if MAX_BUFFER_CACHE
#ifndef SCFS_REMOVE_NO_COMPRESSED_UPPER_MEMCPY
if (alloc_membuffer != 1) {
atomic_set(&sbi->buffer_cache[allocated_index].is_used, 0);
}
#else
if (alloc_membuffer != 1 && compressed) {
atomic_set(&sbi->buffer_cache[allocated_index].is_used, 0);
} else if (alloc_membuffer != 1) {
spin_lock(&sbi->buffer_cache_lock);
sbi->buffer_cache[allocated_index].inode_number = -1;
sbi->buffer_cache[allocated_index].cluster_number = -1;
sbi->buffer_cache[allocated_index].is_compressed = -1;
atomic_set(&sbi->buffer_cache[allocated_index].is_used, -1);
spin_unlock(&sbi->buffer_cache_lock);
}
#endif
#endif
out:
unlock_page(page);
if (alloc_membuffer == 1) {
sbi->buffer_cache_overflow_count_smb++;
scfs_free_mempool_buffer(buffer.c_page, sbi);
scfs_free_mempool_buffer(buffer.u_page, sbi);
}
SCFS_PRINT("-f:%s i:%d c:0x%x u:0x%x\n",
file->f_path.dentry->d_name.name,
page->index, buffer.c_buffer, buffer.u_buffer);
SCFS_PRINT("%s<r> %d\n",file->f_path.dentry->d_name.name, page->index);
if (ret < 0)
return ret;
else if (alloc_membuffer != 1)
return allocated_index + 1;
else
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;
}
* - Prepare a page write, which may require a cluster read and re-compression
* for partially written clusters at the end of a given file. Cluster info list,
* as well as the cluster buffer for the cluster to be written, shall be prepped
* accordingly.
* - Currently SCFS doesn't support random writes, so this function will return
* -EINVAL if pos < i_size.
*
*/
static int scfs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
struct page *page;
struct file *lower_file = NULL;
struct scfs_inode_info *sii = SCFS_I(mapping->host);
struct scfs_cinfo clust_info;
int ret = 0;
SCFS_PRINT("f:%s pos:%lld, len:%d s:%lld\n",
file->f_path.dentry->d_name.name, pos, len,
i_size_read(&sii->vfs_inode));
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
*pagep = page;
if (pos != i_size_read(&sii->vfs_inode)) {
SCFS_PRINT_ERROR("File %s RANDOM write access! pos = %lld, i_size = %lld\n",
file->f_path.dentry->d_name.name,pos,i_size_read(&sii->vfs_inode));
