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-rw-r--r--fs/erofs/data.c452
1 files changed, 452 insertions, 0 deletions
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
new file mode 100644
index 0000000000..0c2c99c58b
--- /dev/null
+++ b/fs/erofs/data.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
+ */
+#include "internal.h"
+#include <linux/prefetch.h>
+#include <linux/sched/mm.h>
+#include <linux/dax.h>
+#include <trace/events/erofs.h>
+
+void erofs_unmap_metabuf(struct erofs_buf *buf)
+{
+ if (buf->kmap_type == EROFS_KMAP)
+ kunmap_local(buf->base);
+ buf->base = NULL;
+ buf->kmap_type = EROFS_NO_KMAP;
+}
+
+void erofs_put_metabuf(struct erofs_buf *buf)
+{
+ if (!buf->page)
+ return;
+ erofs_unmap_metabuf(buf);
+ put_page(buf->page);
+ buf->page = NULL;
+}
+
+/*
+ * Derive the block size from inode->i_blkbits to make compatible with
+ * anonymous inode in fscache mode.
+ */
+void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
+ enum erofs_kmap_type type)
+{
+ struct inode *inode = buf->inode;
+ erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits;
+ pgoff_t index = offset >> PAGE_SHIFT;
+ struct page *page = buf->page;
+ struct folio *folio;
+ unsigned int nofs_flag;
+
+ if (!page || page->index != index) {
+ erofs_put_metabuf(buf);
+
+ nofs_flag = memalloc_nofs_save();
+ folio = read_cache_folio(inode->i_mapping, index, NULL, NULL);
+ memalloc_nofs_restore(nofs_flag);
+ if (IS_ERR(folio))
+ return folio;
+
+ /* should already be PageUptodate, no need to lock page */
+ page = folio_file_page(folio, index);
+ buf->page = page;
+ }
+ if (buf->kmap_type == EROFS_NO_KMAP) {
+ if (type == EROFS_KMAP)
+ buf->base = kmap_local_page(page);
+ buf->kmap_type = type;
+ } else if (buf->kmap_type != type) {
+ DBG_BUGON(1);
+ return ERR_PTR(-EFAULT);
+ }
+ if (type == EROFS_NO_KMAP)
+ return NULL;
+ return buf->base + (offset & ~PAGE_MASK);
+}
+
+void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb)
+{
+ if (erofs_is_fscache_mode(sb))
+ buf->inode = EROFS_SB(sb)->s_fscache->inode;
+ else
+ buf->inode = sb->s_bdev->bd_inode;
+}
+
+void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
+ erofs_blk_t blkaddr, enum erofs_kmap_type type)
+{
+ erofs_init_metabuf(buf, sb);
+ return erofs_bread(buf, blkaddr, type);
+}
+
+static int erofs_map_blocks_flatmode(struct inode *inode,
+ struct erofs_map_blocks *map)
+{
+ erofs_blk_t nblocks, lastblk;
+ u64 offset = map->m_la;
+ struct erofs_inode *vi = EROFS_I(inode);
+ struct super_block *sb = inode->i_sb;
+ bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
+
+ nblocks = erofs_iblks(inode);
+ lastblk = nblocks - tailendpacking;
+
+ /* there is no hole in flatmode */
+ map->m_flags = EROFS_MAP_MAPPED;
+ if (offset < erofs_pos(sb, lastblk)) {
+ map->m_pa = erofs_pos(sb, vi->raw_blkaddr) + map->m_la;
+ map->m_plen = erofs_pos(sb, lastblk) - offset;
+ } else if (tailendpacking) {
+ map->m_pa = erofs_iloc(inode) + vi->inode_isize +
+ vi->xattr_isize + erofs_blkoff(sb, offset);
+ map->m_plen = inode->i_size - offset;
+
+ /* inline data should be located in the same meta block */
+ if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) {
+ erofs_err(sb, "inline data cross block boundary @ nid %llu",
+ vi->nid);
+ DBG_BUGON(1);
+ return -EFSCORRUPTED;
+ }
+ map->m_flags |= EROFS_MAP_META;
+ } else {
+ erofs_err(sb, "internal error @ nid: %llu (size %llu), m_la 0x%llx",
+ vi->nid, inode->i_size, map->m_la);
+ DBG_BUGON(1);
+ return -EIO;
+ }
+ return 0;
+}
+
+int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map)
+{
+ struct super_block *sb = inode->i_sb;
+ struct erofs_inode *vi = EROFS_I(inode);
+ struct erofs_inode_chunk_index *idx;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ u64 chunknr;
+ unsigned int unit;
+ erofs_off_t pos;
+ void *kaddr;
+ int err = 0;
+
+ trace_erofs_map_blocks_enter(inode, map, 0);
+ map->m_deviceid = 0;
+ if (map->m_la >= inode->i_size) {
+ /* leave out-of-bound access unmapped */
+ map->m_flags = 0;
+ map->m_plen = 0;
+ goto out;
+ }
+
+ if (vi->datalayout != EROFS_INODE_CHUNK_BASED) {
+ err = erofs_map_blocks_flatmode(inode, map);
+ goto out;
+ }
+
+ if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
+ unit = sizeof(*idx); /* chunk index */
+ else
+ unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */
+
+ chunknr = map->m_la >> vi->chunkbits;
+ pos = ALIGN(erofs_iloc(inode) + vi->inode_isize +
+ vi->xattr_isize, unit) + unit * chunknr;
+
+ kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(sb, pos), EROFS_KMAP);
+ if (IS_ERR(kaddr)) {
+ err = PTR_ERR(kaddr);
+ goto out;
+ }
+ map->m_la = chunknr << vi->chunkbits;
+ map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits,
+ round_up(inode->i_size - map->m_la, sb->s_blocksize));
+
+ /* handle block map */
+ if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
+ __le32 *blkaddr = kaddr + erofs_blkoff(sb, pos);
+
+ if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
+ map->m_flags = 0;
+ } else {
+ map->m_pa = erofs_pos(sb, le32_to_cpu(*blkaddr));
+ map->m_flags = EROFS_MAP_MAPPED;
+ }
+ goto out_unlock;
+ }
+ /* parse chunk indexes */
+ idx = kaddr + erofs_blkoff(sb, pos);
+ switch (le32_to_cpu(idx->blkaddr)) {
+ case EROFS_NULL_ADDR:
+ map->m_flags = 0;
+ break;
+ default:
+ map->m_deviceid = le16_to_cpu(idx->device_id) &
+ EROFS_SB(sb)->device_id_mask;
+ map->m_pa = erofs_pos(sb, le32_to_cpu(idx->blkaddr));
+ map->m_flags = EROFS_MAP_MAPPED;
+ break;
+ }
+out_unlock:
+ erofs_put_metabuf(&buf);
+out:
+ if (!err)
+ map->m_llen = map->m_plen;
+ trace_erofs_map_blocks_exit(inode, map, 0, err);
+ return err;
+}
+
+int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
+{
+ struct erofs_dev_context *devs = EROFS_SB(sb)->devs;
+ struct erofs_device_info *dif;
+ int id;
+
+ map->m_bdev = sb->s_bdev;
+ map->m_daxdev = EROFS_SB(sb)->dax_dev;
+ map->m_dax_part_off = EROFS_SB(sb)->dax_part_off;
+ map->m_fscache = EROFS_SB(sb)->s_fscache;
+
+ if (map->m_deviceid) {
+ down_read(&devs->rwsem);
+ dif = idr_find(&devs->tree, map->m_deviceid - 1);
+ if (!dif) {
+ up_read(&devs->rwsem);
+ return -ENODEV;
+ }
+ if (devs->flatdev) {
+ map->m_pa += erofs_pos(sb, dif->mapped_blkaddr);
+ up_read(&devs->rwsem);
+ return 0;
+ }
+ map->m_bdev = dif->bdev;
+ map->m_daxdev = dif->dax_dev;
+ map->m_dax_part_off = dif->dax_part_off;
+ map->m_fscache = dif->fscache;
+ up_read(&devs->rwsem);
+ } else if (devs->extra_devices && !devs->flatdev) {
+ down_read(&devs->rwsem);
+ idr_for_each_entry(&devs->tree, dif, id) {
+ erofs_off_t startoff, length;
+
+ if (!dif->mapped_blkaddr)
+ continue;
+ startoff = erofs_pos(sb, dif->mapped_blkaddr);
+ length = erofs_pos(sb, dif->blocks);
+
+ if (map->m_pa >= startoff &&
+ map->m_pa < startoff + length) {
+ map->m_pa -= startoff;
+ map->m_bdev = dif->bdev;
+ map->m_daxdev = dif->dax_dev;
+ map->m_dax_part_off = dif->dax_part_off;
+ map->m_fscache = dif->fscache;
+ break;
+ }
+ }
+ up_read(&devs->rwsem);
+ }
+ return 0;
+}
+
+static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+ unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
+{
+ int ret;
+ struct super_block *sb = inode->i_sb;
+ struct erofs_map_blocks map;
+ struct erofs_map_dev mdev;
+
+ map.m_la = offset;
+ map.m_llen = length;
+
+ ret = erofs_map_blocks(inode, &map);
+ if (ret < 0)
+ return ret;
+
+ mdev = (struct erofs_map_dev) {
+ .m_deviceid = map.m_deviceid,
+ .m_pa = map.m_pa,
+ };
+ ret = erofs_map_dev(sb, &mdev);
+ if (ret)
+ return ret;
+
+ iomap->offset = map.m_la;
+ if (flags & IOMAP_DAX)
+ iomap->dax_dev = mdev.m_daxdev;
+ else
+ iomap->bdev = mdev.m_bdev;
+ iomap->length = map.m_llen;
+ iomap->flags = 0;
+ iomap->private = NULL;
+
+ if (!(map.m_flags & EROFS_MAP_MAPPED)) {
+ iomap->type = IOMAP_HOLE;
+ iomap->addr = IOMAP_NULL_ADDR;
+ if (!iomap->length)
+ iomap->length = length;
+ return 0;
+ }
+
+ if (map.m_flags & EROFS_MAP_META) {
+ void *ptr;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+
+ iomap->type = IOMAP_INLINE;
+ ptr = erofs_read_metabuf(&buf, sb,
+ erofs_blknr(sb, mdev.m_pa), EROFS_KMAP);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+ iomap->inline_data = ptr + erofs_blkoff(sb, mdev.m_pa);
+ iomap->private = buf.base;
+ } else {
+ iomap->type = IOMAP_MAPPED;
+ iomap->addr = mdev.m_pa;
+ if (flags & IOMAP_DAX)
+ iomap->addr += mdev.m_dax_part_off;
+ }
+ return 0;
+}
+
+static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
+ ssize_t written, unsigned int flags, struct iomap *iomap)
+{
+ void *ptr = iomap->private;
+
+ if (ptr) {
+ struct erofs_buf buf = {
+ .page = kmap_to_page(ptr),
+ .base = ptr,
+ .kmap_type = EROFS_KMAP,
+ };
+
+ DBG_BUGON(iomap->type != IOMAP_INLINE);
+ erofs_put_metabuf(&buf);
+ } else {
+ DBG_BUGON(iomap->type == IOMAP_INLINE);
+ }
+ return written;
+}
+
+static const struct iomap_ops erofs_iomap_ops = {
+ .iomap_begin = erofs_iomap_begin,
+ .iomap_end = erofs_iomap_end,
+};
+
+int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len)
+{
+ if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
+#ifdef CONFIG_EROFS_FS_ZIP
+ return iomap_fiemap(inode, fieinfo, start, len,
+ &z_erofs_iomap_report_ops);
+#else
+ return -EOPNOTSUPP;
+#endif
+ }
+ return iomap_fiemap(inode, fieinfo, start, len, &erofs_iomap_ops);
+}
+
+/*
+ * since we dont have write or truncate flows, so no inode
+ * locking needs to be held at the moment.
+ */
+static int erofs_read_folio(struct file *file, struct folio *folio)
+{
+ return iomap_read_folio(folio, &erofs_iomap_ops);
+}
+
+static void erofs_readahead(struct readahead_control *rac)
+{
+ return iomap_readahead(rac, &erofs_iomap_ops);
+}
+
+static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
+{
+ return iomap_bmap(mapping, block, &erofs_iomap_ops);
+}
+
+static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ /* no need taking (shared) inode lock since it's a ro filesystem */
+ if (!iov_iter_count(to))
+ return 0;
+
+#ifdef CONFIG_FS_DAX
+ if (IS_DAX(inode))
+ return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
+#endif
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ unsigned int blksize_mask;
+
+ if (bdev)
+ blksize_mask = bdev_logical_block_size(bdev) - 1;
+ else
+ blksize_mask = i_blocksize(inode) - 1;
+
+ if ((iocb->ki_pos | iov_iter_count(to) |
+ iov_iter_alignment(to)) & blksize_mask)
+ return -EINVAL;
+
+ return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
+ NULL, 0, NULL, 0);
+ }
+ return filemap_read(iocb, to, 0);
+}
+
+/* for uncompressed (aligned) files and raw access for other files */
+const struct address_space_operations erofs_raw_access_aops = {
+ .read_folio = erofs_read_folio,
+ .readahead = erofs_readahead,
+ .bmap = erofs_bmap,
+ .direct_IO = noop_direct_IO,
+ .release_folio = iomap_release_folio,
+ .invalidate_folio = iomap_invalidate_folio,
+};
+
+#ifdef CONFIG_FS_DAX
+static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf,
+ unsigned int order)
+{
+ return dax_iomap_fault(vmf, order, NULL, NULL, &erofs_iomap_ops);
+}
+
+static vm_fault_t erofs_dax_fault(struct vm_fault *vmf)
+{
+ return erofs_dax_huge_fault(vmf, 0);
+}
+
+static const struct vm_operations_struct erofs_dax_vm_ops = {
+ .fault = erofs_dax_fault,
+ .huge_fault = erofs_dax_huge_fault,
+};
+
+static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ if (!IS_DAX(file_inode(file)))
+ return generic_file_readonly_mmap(file, vma);
+
+ if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
+ return -EINVAL;
+
+ vma->vm_ops = &erofs_dax_vm_ops;
+ vm_flags_set(vma, VM_HUGEPAGE);
+ return 0;
+}
+#else
+#define erofs_file_mmap generic_file_readonly_mmap
+#endif
+
+const struct file_operations erofs_file_fops = {
+ .llseek = generic_file_llseek,
+ .read_iter = erofs_file_read_iter,
+ .mmap = erofs_file_mmap,
+ .splice_read = filemap_splice_read,
+};