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-rw-r--r--fs/erofs/data.c138
1 files changed, 88 insertions, 50 deletions
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 0e35ef3f9f3d..e18476c85fa2 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -9,37 +9,71 @@
#include <linux/dax.h>
#include <trace/events/erofs.h>
-struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr)
+void erofs_unmap_metabuf(struct erofs_buf *buf)
+{
+ if (buf->kmap_type == EROFS_KMAP)
+ kunmap(buf->page);
+ else if (buf->kmap_type == EROFS_KMAP_ATOMIC)
+ kunmap_atomic(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;
+}
+
+void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
+ erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
- struct page *page;
-
- page = read_cache_page_gfp(mapping, blkaddr,
- mapping_gfp_constraint(mapping, ~__GFP_FS));
- /* should already be PageUptodate */
- if (!IS_ERR(page))
- lock_page(page);
- return page;
+ erofs_off_t offset = blknr_to_addr(blkaddr);
+ pgoff_t index = offset >> PAGE_SHIFT;
+ struct page *page = buf->page;
+
+ if (!page || page->index != index) {
+ erofs_put_metabuf(buf);
+ page = read_cache_page_gfp(mapping, index,
+ mapping_gfp_constraint(mapping, ~__GFP_FS));
+ if (IS_ERR(page))
+ return page;
+ /* should already be PageUptodate, no need to lock page */
+ buf->page = page;
+ }
+ if (buf->kmap_type == EROFS_NO_KMAP) {
+ if (type == EROFS_KMAP)
+ buf->base = kmap(page);
+ else if (type == EROFS_KMAP_ATOMIC)
+ buf->base = kmap_atomic(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);
}
static int erofs_map_blocks_flatmode(struct inode *inode,
struct erofs_map_blocks *map,
int flags)
{
- int err = 0;
erofs_blk_t nblocks, lastblk;
u64 offset = map->m_la;
struct erofs_inode *vi = EROFS_I(inode);
bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
- trace_erofs_map_blocks_flatmode_enter(inode, map, flags);
-
- nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
+ nblocks = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
lastblk = nblocks - tailendpacking;
/* there is no hole in flatmode */
map->m_flags = EROFS_MAP_MAPPED;
-
if (offset < blknr_to_addr(lastblk)) {
map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
map->m_plen = blknr_to_addr(lastblk) - offset;
@@ -51,30 +85,23 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
vi->xattr_isize + erofs_blkoff(map->m_la);
map->m_plen = inode->i_size - offset;
- /* inline data should be located in one meta block */
- if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
+ /* inline data should be located in the same meta block */
+ if (erofs_blkoff(map->m_pa) + map->m_plen > EROFS_BLKSIZ) {
erofs_err(inode->i_sb,
"inline data cross block boundary @ nid %llu",
vi->nid);
DBG_BUGON(1);
- err = -EFSCORRUPTED;
- goto err_out;
+ return -EFSCORRUPTED;
}
-
map->m_flags |= EROFS_MAP_META;
} else {
erofs_err(inode->i_sb,
"internal error @ nid: %llu (size %llu), m_la 0x%llx",
vi->nid, inode->i_size, map->m_la);
DBG_BUGON(1);
- err = -EIO;
- goto err_out;
+ return -EIO;
}
-
- map->m_llen = map->m_plen;
-err_out:
- trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
- return err;
+ return 0;
}
static int erofs_map_blocks(struct inode *inode,
@@ -83,12 +110,14 @@ static int erofs_map_blocks(struct inode *inode,
struct super_block *sb = inode->i_sb;
struct erofs_inode *vi = EROFS_I(inode);
struct erofs_inode_chunk_index *idx;
- struct page *page;
+ 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, flags);
map->m_deviceid = 0;
if (map->m_la >= inode->i_size) {
/* leave out-of-bound access unmapped */
@@ -97,8 +126,10 @@ static int erofs_map_blocks(struct inode *inode,
goto out;
}
- if (vi->datalayout != EROFS_INODE_CHUNK_BASED)
- return erofs_map_blocks_flatmode(inode, map, flags);
+ if (vi->datalayout != EROFS_INODE_CHUNK_BASED) {
+ err = erofs_map_blocks_flatmode(inode, map, flags);
+ goto out;
+ }
if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
unit = sizeof(*idx); /* chunk index */
@@ -109,17 +140,18 @@ static int erofs_map_blocks(struct inode *inode,
pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
vi->xattr_isize, unit) + unit * chunknr;
- page = erofs_get_meta_page(inode->i_sb, erofs_blknr(pos));
- if (IS_ERR(page))
- return PTR_ERR(page);
-
+ kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(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,
roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));
/* handle block map */
if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
- __le32 *blkaddr = page_address(page) + erofs_blkoff(pos);
+ __le32 *blkaddr = kaddr + erofs_blkoff(pos);
if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
map->m_flags = 0;
@@ -130,7 +162,7 @@ static int erofs_map_blocks(struct inode *inode,
goto out_unlock;
}
/* parse chunk indexes */
- idx = page_address(page) + erofs_blkoff(pos);
+ idx = kaddr + erofs_blkoff(pos);
switch (le32_to_cpu(idx->blkaddr)) {
case EROFS_NULL_ADDR:
map->m_flags = 0;
@@ -143,10 +175,11 @@ static int erofs_map_blocks(struct inode *inode,
break;
}
out_unlock:
- unlock_page(page);
- put_page(page);
+ erofs_put_metabuf(&buf);
out:
- map->m_llen = map->m_plen;
+ if (!err)
+ map->m_llen = map->m_plen;
+ trace_erofs_map_blocks_exit(inode, map, flags, 0);
return err;
}
@@ -231,16 +264,16 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
}
if (map.m_flags & EROFS_MAP_META) {
- struct page *ipage;
+ void *ptr;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
iomap->type = IOMAP_INLINE;
- ipage = erofs_get_meta_page(inode->i_sb,
- erofs_blknr(mdev.m_pa));
- if (IS_ERR(ipage))
- return PTR_ERR(ipage);
- iomap->inline_data = page_address(ipage) +
- erofs_blkoff(mdev.m_pa);
- iomap->private = ipage;
+ ptr = erofs_read_metabuf(&buf, inode->i_sb,
+ erofs_blknr(mdev.m_pa), EROFS_KMAP);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+ iomap->inline_data = ptr + erofs_blkoff(mdev.m_pa);
+ iomap->private = buf.base;
} else {
iomap->type = IOMAP_MAPPED;
iomap->addr = mdev.m_pa;
@@ -251,12 +284,17 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
ssize_t written, unsigned int flags, struct iomap *iomap)
{
- struct page *ipage = iomap->private;
+ void *ptr = iomap->private;
+
+ if (ptr) {
+ struct erofs_buf buf = {
+ .page = kmap_to_page(ptr),
+ .base = ptr,
+ .kmap_type = EROFS_KMAP,
+ };
- if (ipage) {
DBG_BUGON(iomap->type != IOMAP_INLINE);
- unlock_page(ipage);
- put_page(ipage);
+ erofs_put_metabuf(&buf);
} else {
DBG_BUGON(iomap->type == IOMAP_INLINE);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.