612 lines
15 KiB
C
612 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2022, Alibaba Cloud
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* Copyright (C) 2022, Bytedance Inc. All rights reserved.
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*/
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#include <linux/fscache.h>
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#include "internal.h"
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static DEFINE_MUTEX(erofs_domain_list_lock);
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static DEFINE_MUTEX(erofs_domain_cookies_lock);
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static LIST_HEAD(erofs_domain_list);
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static LIST_HEAD(erofs_domain_cookies_list);
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static struct vfsmount *erofs_pseudo_mnt;
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struct erofs_fscache_request {
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struct erofs_fscache_request *primary;
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struct netfs_cache_resources cache_resources;
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struct address_space *mapping; /* The mapping being accessed */
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loff_t start; /* Start position */
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size_t len; /* Length of the request */
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size_t submitted; /* Length of submitted */
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short error; /* 0 or error that occurred */
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refcount_t ref;
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};
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static struct erofs_fscache_request *erofs_fscache_req_alloc(struct address_space *mapping,
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loff_t start, size_t len)
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{
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struct erofs_fscache_request *req;
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req = kzalloc(sizeof(struct erofs_fscache_request), GFP_KERNEL);
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if (!req)
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return ERR_PTR(-ENOMEM);
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req->mapping = mapping;
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req->start = start;
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req->len = len;
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refcount_set(&req->ref, 1);
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return req;
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}
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static struct erofs_fscache_request *erofs_fscache_req_chain(struct erofs_fscache_request *primary,
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size_t len)
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{
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struct erofs_fscache_request *req;
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/* use primary request for the first submission */
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if (!primary->submitted) {
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refcount_inc(&primary->ref);
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return primary;
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}
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req = erofs_fscache_req_alloc(primary->mapping,
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primary->start + primary->submitted, len);
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if (!IS_ERR(req)) {
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req->primary = primary;
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refcount_inc(&primary->ref);
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}
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return req;
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}
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static void erofs_fscache_req_complete(struct erofs_fscache_request *req)
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{
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struct folio *folio;
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bool failed = req->error;
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pgoff_t start_page = req->start / PAGE_SIZE;
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pgoff_t last_page = ((req->start + req->len) / PAGE_SIZE) - 1;
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XA_STATE(xas, &req->mapping->i_pages, start_page);
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rcu_read_lock();
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xas_for_each(&xas, folio, last_page) {
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if (xas_retry(&xas, folio))
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continue;
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if (!failed)
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folio_mark_uptodate(folio);
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folio_unlock(folio);
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}
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rcu_read_unlock();
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}
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static void erofs_fscache_req_put(struct erofs_fscache_request *req)
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{
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if (refcount_dec_and_test(&req->ref)) {
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if (req->cache_resources.ops)
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req->cache_resources.ops->end_operation(&req->cache_resources);
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if (!req->primary)
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erofs_fscache_req_complete(req);
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else
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erofs_fscache_req_put(req->primary);
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kfree(req);
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}
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}
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static void erofs_fscache_subreq_complete(void *priv,
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ssize_t transferred_or_error, bool was_async)
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{
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struct erofs_fscache_request *req = priv;
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if (IS_ERR_VALUE(transferred_or_error)) {
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if (req->primary)
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req->primary->error = transferred_or_error;
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else
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req->error = transferred_or_error;
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}
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erofs_fscache_req_put(req);
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}
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/*
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* Read data from fscache (cookie, pstart, len), and fill the read data into
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* page cache described by (req->mapping, lstart, len). @pstart describeis the
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* start physical address in the cache file.
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*/
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static int erofs_fscache_read_folios_async(struct fscache_cookie *cookie,
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struct erofs_fscache_request *req, loff_t pstart, size_t len)
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{
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enum netfs_io_source source;
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struct super_block *sb = req->mapping->host->i_sb;
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struct netfs_cache_resources *cres = &req->cache_resources;
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struct iov_iter iter;
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loff_t lstart = req->start + req->submitted;
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size_t done = 0;
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int ret;
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DBG_BUGON(len > req->len - req->submitted);
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ret = fscache_begin_read_operation(cres, cookie);
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if (ret)
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return ret;
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while (done < len) {
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loff_t sstart = pstart + done;
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size_t slen = len - done;
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unsigned long flags = 1 << NETFS_SREQ_ONDEMAND;
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source = cres->ops->prepare_ondemand_read(cres,
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sstart, &slen, LLONG_MAX, &flags, 0);
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if (WARN_ON(slen == 0))
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source = NETFS_INVALID_READ;
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if (source != NETFS_READ_FROM_CACHE) {
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erofs_err(sb, "failed to fscache prepare_read (source %d)", source);
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return -EIO;
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}
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refcount_inc(&req->ref);
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iov_iter_xarray(&iter, ITER_DEST, &req->mapping->i_pages,
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lstart + done, slen);
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ret = fscache_read(cres, sstart, &iter, NETFS_READ_HOLE_FAIL,
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erofs_fscache_subreq_complete, req);
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if (ret == -EIOCBQUEUED)
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ret = 0;
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if (ret) {
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erofs_err(sb, "failed to fscache_read (ret %d)", ret);
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return ret;
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}
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done += slen;
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}
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DBG_BUGON(done != len);
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return 0;
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}
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static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)
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{
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int ret;
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struct erofs_fscache *ctx = folio_mapping(folio)->host->i_private;
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struct erofs_fscache_request *req;
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req = erofs_fscache_req_alloc(folio_mapping(folio),
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folio_pos(folio), folio_size(folio));
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if (IS_ERR(req)) {
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folio_unlock(folio);
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return PTR_ERR(req);
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}
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ret = erofs_fscache_read_folios_async(ctx->cookie, req,
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folio_pos(folio), folio_size(folio));
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if (ret)
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req->error = ret;
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erofs_fscache_req_put(req);
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return ret;
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}
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static int erofs_fscache_data_read_slice(struct erofs_fscache_request *primary)
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{
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struct address_space *mapping = primary->mapping;
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struct inode *inode = mapping->host;
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struct super_block *sb = inode->i_sb;
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struct erofs_fscache_request *req;
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struct erofs_map_blocks map;
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struct erofs_map_dev mdev;
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struct iov_iter iter;
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loff_t pos = primary->start + primary->submitted;
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size_t count;
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int ret;
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map.m_la = pos;
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ret = erofs_map_blocks(inode, &map);
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if (ret)
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return ret;
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if (map.m_flags & EROFS_MAP_META) {
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struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
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erofs_blk_t blknr;
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size_t offset, size;
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void *src;
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/* For tail packing layout, the offset may be non-zero. */
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offset = erofs_blkoff(map.m_pa);
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blknr = erofs_blknr(map.m_pa);
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size = map.m_llen;
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src = erofs_read_metabuf(&buf, sb, blknr, EROFS_KMAP);
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if (IS_ERR(src))
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return PTR_ERR(src);
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iov_iter_xarray(&iter, ITER_DEST, &mapping->i_pages, pos, PAGE_SIZE);
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if (copy_to_iter(src + offset, size, &iter) != size) {
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erofs_put_metabuf(&buf);
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return -EFAULT;
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}
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iov_iter_zero(PAGE_SIZE - size, &iter);
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erofs_put_metabuf(&buf);
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primary->submitted += PAGE_SIZE;
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return 0;
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}
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count = primary->len - primary->submitted;
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if (!(map.m_flags & EROFS_MAP_MAPPED)) {
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iov_iter_xarray(&iter, ITER_DEST, &mapping->i_pages, pos, count);
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iov_iter_zero(count, &iter);
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primary->submitted += count;
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return 0;
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}
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count = min_t(size_t, map.m_llen - (pos - map.m_la), count);
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DBG_BUGON(!count || count % PAGE_SIZE);
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mdev = (struct erofs_map_dev) {
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.m_deviceid = map.m_deviceid,
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.m_pa = map.m_pa,
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};
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ret = erofs_map_dev(sb, &mdev);
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if (ret)
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return ret;
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req = erofs_fscache_req_chain(primary, count);
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if (IS_ERR(req))
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return PTR_ERR(req);
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ret = erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
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req, mdev.m_pa + (pos - map.m_la), count);
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erofs_fscache_req_put(req);
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primary->submitted += count;
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return ret;
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}
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static int erofs_fscache_data_read(struct erofs_fscache_request *req)
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{
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int ret;
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do {
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ret = erofs_fscache_data_read_slice(req);
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if (ret)
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req->error = ret;
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} while (!ret && req->submitted < req->len);
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return ret;
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}
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static int erofs_fscache_read_folio(struct file *file, struct folio *folio)
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{
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struct erofs_fscache_request *req;
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int ret;
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req = erofs_fscache_req_alloc(folio_mapping(folio),
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folio_pos(folio), folio_size(folio));
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if (IS_ERR(req)) {
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folio_unlock(folio);
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return PTR_ERR(req);
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}
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ret = erofs_fscache_data_read(req);
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erofs_fscache_req_put(req);
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return ret;
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}
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static void erofs_fscache_readahead(struct readahead_control *rac)
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{
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struct erofs_fscache_request *req;
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if (!readahead_count(rac))
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return;
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req = erofs_fscache_req_alloc(rac->mapping,
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readahead_pos(rac), readahead_length(rac));
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if (IS_ERR(req))
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return;
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/* The request completion will drop refs on the folios. */
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while (readahead_folio(rac))
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;
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erofs_fscache_data_read(req);
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erofs_fscache_req_put(req);
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}
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static const struct address_space_operations erofs_fscache_meta_aops = {
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.read_folio = erofs_fscache_meta_read_folio,
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};
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const struct address_space_operations erofs_fscache_access_aops = {
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.read_folio = erofs_fscache_read_folio,
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.readahead = erofs_fscache_readahead,
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};
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static void erofs_fscache_domain_put(struct erofs_domain *domain)
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{
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mutex_lock(&erofs_domain_list_lock);
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if (refcount_dec_and_test(&domain->ref)) {
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list_del(&domain->list);
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if (list_empty(&erofs_domain_list)) {
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kern_unmount(erofs_pseudo_mnt);
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erofs_pseudo_mnt = NULL;
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}
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fscache_relinquish_volume(domain->volume, NULL, false);
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mutex_unlock(&erofs_domain_list_lock);
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kfree(domain->domain_id);
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kfree(domain);
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return;
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}
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mutex_unlock(&erofs_domain_list_lock);
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}
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static int erofs_fscache_register_volume(struct super_block *sb)
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{
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struct erofs_sb_info *sbi = EROFS_SB(sb);
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char *domain_id = sbi->domain_id;
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struct fscache_volume *volume;
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char *name;
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int ret = 0;
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name = kasprintf(GFP_KERNEL, "erofs,%s",
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domain_id ? domain_id : sbi->fsid);
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if (!name)
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return -ENOMEM;
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volume = fscache_acquire_volume(name, NULL, NULL, 0);
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if (IS_ERR_OR_NULL(volume)) {
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erofs_err(sb, "failed to register volume for %s", name);
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ret = volume ? PTR_ERR(volume) : -EOPNOTSUPP;
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volume = NULL;
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}
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sbi->volume = volume;
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kfree(name);
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return ret;
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}
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static int erofs_fscache_init_domain(struct super_block *sb)
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{
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int err;
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struct erofs_domain *domain;
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struct erofs_sb_info *sbi = EROFS_SB(sb);
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domain = kzalloc(sizeof(struct erofs_domain), GFP_KERNEL);
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if (!domain)
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return -ENOMEM;
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domain->domain_id = kstrdup(sbi->domain_id, GFP_KERNEL);
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if (!domain->domain_id) {
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kfree(domain);
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return -ENOMEM;
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}
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err = erofs_fscache_register_volume(sb);
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if (err)
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goto out;
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if (!erofs_pseudo_mnt) {
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erofs_pseudo_mnt = kern_mount(&erofs_fs_type);
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if (IS_ERR(erofs_pseudo_mnt)) {
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err = PTR_ERR(erofs_pseudo_mnt);
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goto out;
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}
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}
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domain->volume = sbi->volume;
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refcount_set(&domain->ref, 1);
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list_add(&domain->list, &erofs_domain_list);
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sbi->domain = domain;
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return 0;
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out:
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kfree(domain->domain_id);
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kfree(domain);
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return err;
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}
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static int erofs_fscache_register_domain(struct super_block *sb)
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{
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int err;
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struct erofs_domain *domain;
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struct erofs_sb_info *sbi = EROFS_SB(sb);
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mutex_lock(&erofs_domain_list_lock);
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list_for_each_entry(domain, &erofs_domain_list, list) {
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if (!strcmp(domain->domain_id, sbi->domain_id)) {
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sbi->domain = domain;
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sbi->volume = domain->volume;
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refcount_inc(&domain->ref);
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mutex_unlock(&erofs_domain_list_lock);
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return 0;
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}
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}
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err = erofs_fscache_init_domain(sb);
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mutex_unlock(&erofs_domain_list_lock);
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return err;
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}
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static struct erofs_fscache *erofs_fscache_acquire_cookie(struct super_block *sb,
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char *name, unsigned int flags)
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{
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struct fscache_volume *volume = EROFS_SB(sb)->volume;
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struct erofs_fscache *ctx;
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struct fscache_cookie *cookie;
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struct super_block *isb;
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struct inode *inode;
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int ret;
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ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return ERR_PTR(-ENOMEM);
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INIT_LIST_HEAD(&ctx->node);
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refcount_set(&ctx->ref, 1);
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cookie = fscache_acquire_cookie(volume, FSCACHE_ADV_WANT_CACHE_SIZE,
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name, strlen(name), NULL, 0, 0);
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if (!cookie) {
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erofs_err(sb, "failed to get cookie for %s", name);
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ret = -EINVAL;
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goto err;
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}
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fscache_use_cookie(cookie, false);
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/*
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* Allocate anonymous inode in global pseudo mount for shareable blobs,
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* so that they are accessible among erofs fs instances.
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*/
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isb = flags & EROFS_REG_COOKIE_SHARE ? erofs_pseudo_mnt->mnt_sb : sb;
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inode = new_inode(isb);
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if (!inode) {
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erofs_err(sb, "failed to get anon inode for %s", name);
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ret = -ENOMEM;
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goto err_cookie;
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}
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inode->i_size = OFFSET_MAX;
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inode->i_mapping->a_ops = &erofs_fscache_meta_aops;
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mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
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inode->i_private = ctx;
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ctx->cookie = cookie;
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ctx->inode = inode;
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return ctx;
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err_cookie:
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fscache_unuse_cookie(cookie, NULL, NULL);
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fscache_relinquish_cookie(cookie, false);
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err:
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kfree(ctx);
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return ERR_PTR(ret);
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}
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static void erofs_fscache_relinquish_cookie(struct erofs_fscache *ctx)
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{
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fscache_unuse_cookie(ctx->cookie, NULL, NULL);
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fscache_relinquish_cookie(ctx->cookie, false);
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iput(ctx->inode);
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kfree(ctx->name);
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kfree(ctx);
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}
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static struct erofs_fscache *erofs_domain_init_cookie(struct super_block *sb,
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char *name, unsigned int flags)
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{
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struct erofs_fscache *ctx;
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struct erofs_domain *domain = EROFS_SB(sb)->domain;
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ctx = erofs_fscache_acquire_cookie(sb, name, flags);
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if (IS_ERR(ctx))
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return ctx;
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ctx->name = kstrdup(name, GFP_KERNEL);
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if (!ctx->name) {
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erofs_fscache_relinquish_cookie(ctx);
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return ERR_PTR(-ENOMEM);
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}
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refcount_inc(&domain->ref);
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ctx->domain = domain;
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list_add(&ctx->node, &erofs_domain_cookies_list);
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return ctx;
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}
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static struct erofs_fscache *erofs_domain_register_cookie(struct super_block *sb,
|
|
char *name, unsigned int flags)
|
|
{
|
|
struct erofs_fscache *ctx;
|
|
struct erofs_domain *domain = EROFS_SB(sb)->domain;
|
|
|
|
flags |= EROFS_REG_COOKIE_SHARE;
|
|
mutex_lock(&erofs_domain_cookies_lock);
|
|
list_for_each_entry(ctx, &erofs_domain_cookies_list, node) {
|
|
if (ctx->domain != domain || strcmp(ctx->name, name))
|
|
continue;
|
|
if (!(flags & EROFS_REG_COOKIE_NEED_NOEXIST)) {
|
|
refcount_inc(&ctx->ref);
|
|
} else {
|
|
erofs_err(sb, "%s already exists in domain %s", name,
|
|
domain->domain_id);
|
|
ctx = ERR_PTR(-EEXIST);
|
|
}
|
|
mutex_unlock(&erofs_domain_cookies_lock);
|
|
return ctx;
|
|
}
|
|
ctx = erofs_domain_init_cookie(sb, name, flags);
|
|
mutex_unlock(&erofs_domain_cookies_lock);
|
|
return ctx;
|
|
}
|
|
|
|
struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
|
|
char *name,
|
|
unsigned int flags)
|
|
{
|
|
if (EROFS_SB(sb)->domain_id)
|
|
return erofs_domain_register_cookie(sb, name, flags);
|
|
return erofs_fscache_acquire_cookie(sb, name, flags);
|
|
}
|
|
|
|
void erofs_fscache_unregister_cookie(struct erofs_fscache *ctx)
|
|
{
|
|
struct erofs_domain *domain = NULL;
|
|
|
|
if (!ctx)
|
|
return;
|
|
if (!ctx->domain)
|
|
return erofs_fscache_relinquish_cookie(ctx);
|
|
|
|
mutex_lock(&erofs_domain_cookies_lock);
|
|
if (refcount_dec_and_test(&ctx->ref)) {
|
|
domain = ctx->domain;
|
|
list_del(&ctx->node);
|
|
erofs_fscache_relinquish_cookie(ctx);
|
|
}
|
|
mutex_unlock(&erofs_domain_cookies_lock);
|
|
if (domain)
|
|
erofs_fscache_domain_put(domain);
|
|
}
|
|
|
|
int erofs_fscache_register_fs(struct super_block *sb)
|
|
{
|
|
int ret;
|
|
struct erofs_sb_info *sbi = EROFS_SB(sb);
|
|
struct erofs_fscache *fscache;
|
|
unsigned int flags = 0;
|
|
|
|
if (sbi->domain_id)
|
|
ret = erofs_fscache_register_domain(sb);
|
|
else
|
|
ret = erofs_fscache_register_volume(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* When shared domain is enabled, using NEED_NOEXIST to guarantee
|
|
* the primary data blob (aka fsid) is unique in the shared domain.
|
|
*
|
|
* For non-shared-domain case, fscache_acquire_volume() invoked by
|
|
* erofs_fscache_register_volume() has already guaranteed
|
|
* the uniqueness of primary data blob.
|
|
*
|
|
* Acquired domain/volume will be relinquished in kill_sb() on error.
|
|
*/
|
|
if (sbi->domain_id)
|
|
flags |= EROFS_REG_COOKIE_NEED_NOEXIST;
|
|
fscache = erofs_fscache_register_cookie(sb, sbi->fsid, flags);
|
|
if (IS_ERR(fscache))
|
|
return PTR_ERR(fscache);
|
|
|
|
sbi->s_fscache = fscache;
|
|
return 0;
|
|
}
|
|
|
|
void erofs_fscache_unregister_fs(struct super_block *sb)
|
|
{
|
|
struct erofs_sb_info *sbi = EROFS_SB(sb);
|
|
|
|
erofs_fscache_unregister_cookie(sbi->s_fscache);
|
|
|
|
if (sbi->domain)
|
|
erofs_fscache_domain_put(sbi->domain);
|
|
else
|
|
fscache_relinquish_volume(sbi->volume, NULL, false);
|
|
|
|
sbi->s_fscache = NULL;
|
|
sbi->volume = NULL;
|
|
sbi->domain = NULL;
|
|
}
|