--- /dev/null
- static int erofs_fscache_meta_readpage(struct file *data, struct page *page)
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022, Alibaba Cloud
+ */
+#include <linux/fscache.h>
+#include "internal.h"
+
+static struct netfs_io_request *erofs_fscache_alloc_request(struct address_space *mapping,
+ loff_t start, size_t len)
+{
+ struct netfs_io_request *rreq;
+
+ rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
+ if (!rreq)
+ return ERR_PTR(-ENOMEM);
+
+ rreq->start = start;
+ rreq->len = len;
+ rreq->mapping = mapping;
+ INIT_LIST_HEAD(&rreq->subrequests);
+ refcount_set(&rreq->ref, 1);
+ return rreq;
+}
+
+static void erofs_fscache_put_request(struct netfs_io_request *rreq)
+{
+ if (!refcount_dec_and_test(&rreq->ref))
+ return;
+ if (rreq->cache_resources.ops)
+ rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
+ kfree(rreq);
+}
+
+static void erofs_fscache_put_subrequest(struct netfs_io_subrequest *subreq)
+{
+ if (!refcount_dec_and_test(&subreq->ref))
+ return;
+ erofs_fscache_put_request(subreq->rreq);
+ kfree(subreq);
+}
+
+static void erofs_fscache_clear_subrequests(struct netfs_io_request *rreq)
+{
+ struct netfs_io_subrequest *subreq;
+
+ while (!list_empty(&rreq->subrequests)) {
+ subreq = list_first_entry(&rreq->subrequests,
+ struct netfs_io_subrequest, rreq_link);
+ list_del(&subreq->rreq_link);
+ erofs_fscache_put_subrequest(subreq);
+ }
+}
+
+static void erofs_fscache_rreq_unlock_folios(struct netfs_io_request *rreq)
+{
+ struct netfs_io_subrequest *subreq;
+ struct folio *folio;
+ unsigned int iopos = 0;
+ pgoff_t start_page = rreq->start / PAGE_SIZE;
+ pgoff_t last_page = ((rreq->start + rreq->len) / PAGE_SIZE) - 1;
+ bool subreq_failed = false;
+
+ XA_STATE(xas, &rreq->mapping->i_pages, start_page);
+
+ subreq = list_first_entry(&rreq->subrequests,
+ struct netfs_io_subrequest, rreq_link);
+ subreq_failed = (subreq->error < 0);
+
+ rcu_read_lock();
+ xas_for_each(&xas, folio, last_page) {
+ unsigned int pgpos =
+ (folio_index(folio) - start_page) * PAGE_SIZE;
+ unsigned int pgend = pgpos + folio_size(folio);
+ bool pg_failed = false;
+
+ for (;;) {
+ if (!subreq) {
+ pg_failed = true;
+ break;
+ }
+
+ pg_failed |= subreq_failed;
+ if (pgend < iopos + subreq->len)
+ break;
+
+ iopos += subreq->len;
+ if (!list_is_last(&subreq->rreq_link,
+ &rreq->subrequests)) {
+ subreq = list_next_entry(subreq, rreq_link);
+ subreq_failed = (subreq->error < 0);
+ } else {
+ subreq = NULL;
+ subreq_failed = false;
+ }
+ if (pgend == iopos)
+ break;
+ }
+
+ if (!pg_failed)
+ folio_mark_uptodate(folio);
+
+ folio_unlock(folio);
+ }
+ rcu_read_unlock();
+}
+
+static void erofs_fscache_rreq_complete(struct netfs_io_request *rreq)
+{
+ erofs_fscache_rreq_unlock_folios(rreq);
+ erofs_fscache_clear_subrequests(rreq);
+ erofs_fscache_put_request(rreq);
+}
+
+static void erofc_fscache_subreq_complete(void *priv,
+ ssize_t transferred_or_error, bool was_async)
+{
+ struct netfs_io_subrequest *subreq = priv;
+ struct netfs_io_request *rreq = subreq->rreq;
+
+ if (IS_ERR_VALUE(transferred_or_error))
+ subreq->error = transferred_or_error;
+
+ if (atomic_dec_and_test(&rreq->nr_outstanding))
+ erofs_fscache_rreq_complete(rreq);
+
+ erofs_fscache_put_subrequest(subreq);
+}
+
+/*
+ * Read data from fscache and fill the read data into page cache described by
+ * @rreq, which shall be both aligned with PAGE_SIZE. @pstart describes
+ * the start physical address in the cache file.
+ */
+static int erofs_fscache_read_folios_async(struct fscache_cookie *cookie,
+ struct netfs_io_request *rreq, loff_t pstart)
+{
+ enum netfs_io_source source;
+ struct super_block *sb = rreq->mapping->host->i_sb;
+ struct netfs_io_subrequest *subreq;
+ struct netfs_cache_resources *cres = &rreq->cache_resources;
+ struct iov_iter iter;
+ loff_t start = rreq->start;
+ size_t len = rreq->len;
+ size_t done = 0;
+ int ret;
+
+ atomic_set(&rreq->nr_outstanding, 1);
+
+ ret = fscache_begin_read_operation(cres, cookie);
+ if (ret)
+ goto out;
+
+ while (done < len) {
+ subreq = kzalloc(sizeof(struct netfs_io_subrequest),
+ GFP_KERNEL);
+ if (subreq) {
+ INIT_LIST_HEAD(&subreq->rreq_link);
+ refcount_set(&subreq->ref, 2);
+ subreq->rreq = rreq;
+ refcount_inc(&rreq->ref);
+ } else {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ subreq->start = pstart + done;
+ subreq->len = len - done;
+ subreq->flags = 1 << NETFS_SREQ_ONDEMAND;
+
+ list_add_tail(&subreq->rreq_link, &rreq->subrequests);
+
+ source = cres->ops->prepare_read(subreq, LLONG_MAX);
+ if (WARN_ON(subreq->len == 0))
+ source = NETFS_INVALID_READ;
+ if (source != NETFS_READ_FROM_CACHE) {
+ erofs_err(sb, "failed to fscache prepare_read (source %d)",
+ source);
+ ret = -EIO;
+ subreq->error = ret;
+ erofs_fscache_put_subrequest(subreq);
+ goto out;
+ }
+
+ atomic_inc(&rreq->nr_outstanding);
+
+ iov_iter_xarray(&iter, READ, &rreq->mapping->i_pages,
+ start + done, subreq->len);
+
+ ret = fscache_read(cres, subreq->start, &iter,
+ NETFS_READ_HOLE_FAIL,
+ erofc_fscache_subreq_complete, subreq);
+ if (ret == -EIOCBQUEUED)
+ ret = 0;
+ if (ret) {
+ erofs_err(sb, "failed to fscache_read (ret %d)", ret);
+ goto out;
+ }
+
+ done += subreq->len;
+ }
+out:
+ if (atomic_dec_and_test(&rreq->nr_outstanding))
+ erofs_fscache_rreq_complete(rreq);
+
+ return ret;
+}
+
- struct folio *folio = page_folio(page);
++static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)
+{
+ int ret;
- static int erofs_fscache_readpage_inline(struct folio *folio,
+ struct super_block *sb = folio_mapping(folio)->host->i_sb;
+ struct netfs_io_request *rreq;
+ struct erofs_map_dev mdev = {
+ .m_deviceid = 0,
+ .m_pa = folio_pos(folio),
+ };
+
+ ret = erofs_map_dev(sb, &mdev);
+ if (ret)
+ goto out;
+
+ rreq = erofs_fscache_alloc_request(folio_mapping(folio),
+ folio_pos(folio), folio_size(folio));
+ if (IS_ERR(rreq))
+ goto out;
+
+ return erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
+ rreq, mdev.m_pa);
+out:
+ folio_unlock(folio);
+ return ret;
+}
+
- static int erofs_fscache_readpage(struct file *file, struct page *page)
++static int erofs_fscache_read_folio_inline(struct folio *folio,
+ struct erofs_map_blocks *map)
+{
+ struct super_block *sb = folio_mapping(folio)->host->i_sb;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ erofs_blk_t blknr;
+ size_t offset, len;
+ void *src, *dst;
+
+ /* For tail packing layout, the offset may be non-zero. */
+ offset = erofs_blkoff(map->m_pa);
+ blknr = erofs_blknr(map->m_pa);
+ len = map->m_llen;
+
+ src = erofs_read_metabuf(&buf, sb, blknr, EROFS_KMAP);
+ if (IS_ERR(src))
+ return PTR_ERR(src);
+
+ dst = kmap_local_folio(folio, 0);
+ memcpy(dst, src + offset, len);
+ memset(dst + len, 0, PAGE_SIZE - len);
+ kunmap_local(dst);
+
+ erofs_put_metabuf(&buf);
+ return 0;
+}
+
- struct folio *folio = page_folio(page);
++static int erofs_fscache_read_folio(struct file *file, struct folio *folio)
+{
- ret = erofs_fscache_readpage_inline(folio, &map);
+ struct inode *inode = folio_mapping(folio)->host;
+ struct super_block *sb = inode->i_sb;
+ struct erofs_map_blocks map;
+ struct erofs_map_dev mdev;
+ struct netfs_io_request *rreq;
+ erofs_off_t pos;
+ loff_t pstart;
+ int ret;
+
+ DBG_BUGON(folio_size(folio) != EROFS_BLKSIZ);
+
+ pos = folio_pos(folio);
+ map.m_la = pos;
+
+ ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
+ if (ret)
+ goto out_unlock;
+
+ if (!(map.m_flags & EROFS_MAP_MAPPED)) {
+ folio_zero_range(folio, 0, folio_size(folio));
+ goto out_uptodate;
+ }
+
+ if (map.m_flags & EROFS_MAP_META) {
- ret = erofs_fscache_readpage_inline(folio, &map);
++ ret = erofs_fscache_read_folio_inline(folio, &map);
+ goto out_uptodate;
+ }
+
+ mdev = (struct erofs_map_dev) {
+ .m_deviceid = map.m_deviceid,
+ .m_pa = map.m_pa,
+ };
+
+ ret = erofs_map_dev(sb, &mdev);
+ if (ret)
+ goto out_unlock;
+
+
+ rreq = erofs_fscache_alloc_request(folio_mapping(folio),
+ folio_pos(folio), folio_size(folio));
+ if (IS_ERR(rreq))
+ goto out_unlock;
+
+ pstart = mdev.m_pa + (pos - map.m_la);
+ return erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
+ rreq, pstart);
+
+out_uptodate:
+ if (!ret)
+ folio_mark_uptodate(folio);
+out_unlock:
+ folio_unlock(folio);
+ return ret;
+}
+
+static void erofs_fscache_advance_folios(struct readahead_control *rac,
+ size_t len, bool unlock)
+{
+ while (len) {
+ struct folio *folio = readahead_folio(rac);
+ len -= folio_size(folio);
+ if (unlock) {
+ folio_mark_uptodate(folio);
+ folio_unlock(folio);
+ }
+ }
+}
+
+static void erofs_fscache_readahead(struct readahead_control *rac)
+{
+ struct inode *inode = rac->mapping->host;
+ struct super_block *sb = inode->i_sb;
+ size_t len, count, done = 0;
+ erofs_off_t pos;
+ loff_t start, offset;
+ int ret;
+
+ if (!readahead_count(rac))
+ return;
+
+ start = readahead_pos(rac);
+ len = readahead_length(rac);
+
+ do {
+ struct erofs_map_blocks map;
+ struct erofs_map_dev mdev;
+ struct netfs_io_request *rreq;
+
+ pos = start + done;
+ map.m_la = pos;
+
+ ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
+ if (ret)
+ return;
+
+ offset = start + done;
+ count = min_t(size_t, map.m_llen - (pos - map.m_la),
+ len - done);
+
+ if (!(map.m_flags & EROFS_MAP_MAPPED)) {
+ struct iov_iter iter;
+
+ iov_iter_xarray(&iter, READ, &rac->mapping->i_pages,
+ offset, count);
+ iov_iter_zero(count, &iter);
+
+ erofs_fscache_advance_folios(rac, count, true);
+ ret = count;
+ continue;
+ }
+
+ if (map.m_flags & EROFS_MAP_META) {
+ struct folio *folio = readahead_folio(rac);
+
- .readpage = erofs_fscache_meta_readpage,
++ ret = erofs_fscache_read_folio_inline(folio, &map);
+ if (!ret) {
+ folio_mark_uptodate(folio);
+ ret = folio_size(folio);
+ }
+
+ folio_unlock(folio);
+ continue;
+ }
+
+ mdev = (struct erofs_map_dev) {
+ .m_deviceid = map.m_deviceid,
+ .m_pa = map.m_pa,
+ };
+ ret = erofs_map_dev(sb, &mdev);
+ if (ret)
+ return;
+
+ rreq = erofs_fscache_alloc_request(rac->mapping, offset, count);
+ if (IS_ERR(rreq))
+ return;
+ /*
+ * Drop the ref of folios here. Unlock them in
+ * rreq_unlock_folios() when rreq complete.
+ */
+ erofs_fscache_advance_folios(rac, count, false);
+ ret = erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
+ rreq, mdev.m_pa + (pos - map.m_la));
+ if (!ret)
+ ret = count;
+ } while (ret > 0 && ((done += ret) < len));
+}
+
+static const struct address_space_operations erofs_fscache_meta_aops = {
- .readpage = erofs_fscache_readpage,
++ .read_folio = erofs_fscache_meta_read_folio,
+};
+
+const struct address_space_operations erofs_fscache_access_aops = {
++ .read_folio = erofs_fscache_read_folio,
+ .readahead = erofs_fscache_readahead,
+};
+
+int erofs_fscache_register_cookie(struct super_block *sb,
+ struct erofs_fscache **fscache,
+ char *name, bool need_inode)
+{
+ struct fscache_volume *volume = EROFS_SB(sb)->volume;
+ struct erofs_fscache *ctx;
+ struct fscache_cookie *cookie;
+ int ret;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ cookie = fscache_acquire_cookie(volume, FSCACHE_ADV_WANT_CACHE_SIZE,
+ name, strlen(name), NULL, 0, 0);
+ if (!cookie) {
+ erofs_err(sb, "failed to get cookie for %s", name);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ fscache_use_cookie(cookie, false);
+ ctx->cookie = cookie;
+
+ if (need_inode) {
+ struct inode *const inode = new_inode(sb);
+
+ if (!inode) {
+ erofs_err(sb, "failed to get anon inode for %s", name);
+ ret = -ENOMEM;
+ goto err_cookie;
+ }
+
+ set_nlink(inode, 1);
+ inode->i_size = OFFSET_MAX;
+ inode->i_mapping->a_ops = &erofs_fscache_meta_aops;
+ mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
+
+ ctx->inode = inode;
+ }
+
+ *fscache = ctx;
+ return 0;
+
+err_cookie:
+ fscache_unuse_cookie(ctx->cookie, NULL, NULL);
+ fscache_relinquish_cookie(ctx->cookie, false);
+ ctx->cookie = NULL;
+err:
+ kfree(ctx);
+ return ret;
+}
+
+void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
+{
+ struct erofs_fscache *ctx = *fscache;
+
+ if (!ctx)
+ return;
+
+ fscache_unuse_cookie(ctx->cookie, NULL, NULL);
+ fscache_relinquish_cookie(ctx->cookie, false);
+ ctx->cookie = NULL;
+
+ iput(ctx->inode);
+ ctx->inode = NULL;
+
+ kfree(ctx);
+ *fscache = NULL;
+}
+
+int erofs_fscache_register_fs(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct fscache_volume *volume;
+ char *name;
+ int ret = 0;
+
+ name = kasprintf(GFP_KERNEL, "erofs,%s", sbi->opt.fsid);
+ if (!name)
+ return -ENOMEM;
+
+ volume = fscache_acquire_volume(name, NULL, NULL, 0);
+ if (IS_ERR_OR_NULL(volume)) {
+ erofs_err(sb, "failed to register volume for %s", name);
+ ret = volume ? PTR_ERR(volume) : -EOPNOTSUPP;
+ volume = NULL;
+ }
+
+ sbi->volume = volume;
+ kfree(name);
+ return ret;
+}
+
+void erofs_fscache_unregister_fs(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+
+ fscache_relinquish_volume(sbi->volume, NULL, false);
+ sbi->volume = NULL;
+}
projects / kernel.git / commitdiff