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-rw-r--r--fs/btrfs/zlib.c73
1 files changed, 19 insertions, 54 deletions
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 36cf1f0e338e..8da66ea699e8 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -354,18 +354,13 @@ done:
}
int zlib_decompress(struct list_head *ws, const u8 *data_in,
- struct page *dest_page, unsigned long start_byte, size_t srclen,
+ struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
size_t destlen)
{
struct workspace *workspace = list_entry(ws, struct workspace, list);
int ret = 0;
int wbits = MAX_WBITS;
- unsigned long bytes_left;
- unsigned long total_out = 0;
- unsigned long pg_offset = 0;
-
- destlen = min_t(unsigned long, destlen, PAGE_SIZE);
- bytes_left = destlen;
+ unsigned long to_copy;
workspace->strm.next_in = data_in;
workspace->strm.avail_in = srclen;
@@ -390,60 +385,30 @@ int zlib_decompress(struct list_head *ws, const u8 *data_in,
return -EIO;
}
- while (bytes_left > 0) {
- unsigned long buf_start;
- unsigned long buf_offset;
- unsigned long bytes;
-
- ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
- if (ret != Z_OK && ret != Z_STREAM_END)
- break;
-
- buf_start = total_out;
- total_out = workspace->strm.total_out;
-
- if (total_out == buf_start) {
- ret = -EIO;
- break;
- }
-
- if (total_out <= start_byte)
- goto next;
-
- if (total_out > start_byte && buf_start < start_byte)
- buf_offset = start_byte - buf_start;
- else
- buf_offset = 0;
-
- bytes = min(PAGE_SIZE - pg_offset,
- PAGE_SIZE - (buf_offset % PAGE_SIZE));
- bytes = min(bytes, bytes_left);
+ /*
+ * Everything (in/out buf) should be at most one sector, there should
+ * be no need to switch any input/output buffer.
+ */
+ ret = zlib_inflate(&workspace->strm, Z_FINISH);
+ to_copy = min(workspace->strm.total_out, destlen);
+ if (ret != Z_STREAM_END)
+ goto out;
- memcpy_to_page(dest_page, pg_offset,
- workspace->buf + buf_offset, bytes);
+ memcpy_to_page(dest_page, dest_pgoff, workspace->buf, to_copy);
- pg_offset += bytes;
- bytes_left -= bytes;
-next:
- workspace->strm.next_out = workspace->buf;
- workspace->strm.avail_out = workspace->buf_size;
- }
-
- if (ret != Z_STREAM_END && bytes_left != 0)
+out:
+ if (unlikely(to_copy != destlen)) {
+ pr_warn_ratelimited("BTRFS: infalte failed, decompressed=%lu expected=%zu\n",
+ to_copy, destlen);
ret = -EIO;
- else
+ } else {
ret = 0;
+ }
zlib_inflateEnd(&workspace->strm);
- /*
- * this should only happen if zlib returned fewer bytes than we
- * expected. btrfs_get_block is responsible for zeroing from the
- * end of the inline extent (destlen) to the end of the page
- */
- if (pg_offset < destlen) {
- memzero_page(dest_page, pg_offset, destlen - pg_offset);
- }
+ if (unlikely(to_copy < destlen))
+ memzero_page(dest_page, dest_pgoff + to_copy, destlen - to_copy);
return ret;
}