erofs-utils: lib: move buffer allocation into z_erofs_write_indexes()

Just used to prepare for extent-based metadata.  No logic changes.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250403081403.2671077-2-hsiangkao@linux.alibaba.com

diff --git a/lib/compress.c b/lib/compress.c
index eaca4d32c77c761ab341c69cb0ebdae7c23131db..50d155e5eb9c6952db6ce44e2789ed50c19da603 100644 (file)
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -121,7 +121,7 @@ static bool z_erofs_mt_enabled;
 
 #define Z_EROFS_LEGACY_MAP_HEADER_SIZE Z_EROFS_FULL_INDEX_ALIGN(0)
 
-static void z_erofs_write_indexes_final(struct z_erofs_compress_ictx *ctx)
+static void z_erofs_fini_full_indexes(struct z_erofs_compress_ictx *ctx)
 {
        const unsigned int type = Z_EROFS_LCLUSTER_TYPE_PLAIN;
        struct z_erofs_lcluster_index di;
@@ -137,8 +137,8 @@ static void z_erofs_write_indexes_final(struct z_erofs_compress_ictx *ctx)
        ctx->metacur += sizeof(di);
 }
 
-static void z_erofs_write_extent(struct z_erofs_compress_ictx *ctx,
-                                struct z_erofs_inmem_extent *e)
+static void z_erofs_write_full_indexes(struct z_erofs_compress_ictx *ctx,
+                                      struct z_erofs_inmem_extent *e)
 {
        struct erofs_inode *inode = ctx->inode;
        struct erofs_sb_info *sbi = inode->sbi;
@@ -236,20 +236,6 @@ static void z_erofs_write_extent(struct z_erofs_compress_ictx *ctx,
        ctx->clusterofs = clusterofs + count;
 }
 
-static void z_erofs_write_indexes(struct z_erofs_compress_ictx *ctx)
-{
-       struct z_erofs_extent_item *ei, *n;
-
-       ctx->clusterofs = 0;
-       list_for_each_entry_safe(ei, n, &ctx->extents, list) {
-               z_erofs_write_extent(ctx, &ei->e);
-
-               list_del(&ei->list);
-               free(ei);
-       }
-       z_erofs_write_indexes_final(ctx);
-}
-
 static bool z_erofs_need_refill(struct z_erofs_compress_sctx *ctx)
 {
        const bool final = !ctx->remaining;
@@ -1012,6 +998,31 @@ static void z_erofs_write_mapheader(struct erofs_inode *inode,
        memcpy(compressmeta, &h, sizeof(struct z_erofs_map_header));
 }
 
+static void *z_erofs_write_indexes(struct z_erofs_compress_ictx *ctx)
+{
+       struct erofs_inode *inode = ctx->inode;
+       struct z_erofs_extent_item *ei, *n;
+       void *metabuf;
+
+       metabuf = malloc(BLK_ROUND_UP(inode->sbi, inode->i_size) *
+                        sizeof(struct z_erofs_lcluster_index) +
+                        Z_EROFS_LEGACY_MAP_HEADER_SIZE);
+       if (!metabuf)
+               return ERR_PTR(-ENOMEM);
+
+       ctx->metacur = metabuf + Z_EROFS_LEGACY_MAP_HEADER_SIZE;
+       ctx->clusterofs = 0;
+       list_for_each_entry_safe(ei, n, &ctx->extents, list) {
+               z_erofs_write_full_indexes(ctx, &ei->e);
+
+               list_del(&ei->list);
+               free(ei);
+       }
+       z_erofs_fini_full_indexes(ctx);
+       z_erofs_write_mapheader(inode, metabuf);
+       return metabuf;
+}
+
 void z_erofs_drop_inline_pcluster(struct erofs_inode *inode)
 {
        struct erofs_sb_info *sbi = inode->sbi;
@@ -1145,15 +1156,11 @@ int erofs_commit_compressed_file(struct z_erofs_compress_ictx *ictx,
        DBG_BUGON(pstart < (!!inode->idata_size) << bbits);
        ptotal -= (!!inode->idata_size) << bbits;
 
-       compressmeta = malloc(BLK_ROUND_UP(sbi, inode->i_size) *
-                             sizeof(struct z_erofs_lcluster_index) +
-                             Z_EROFS_LEGACY_MAP_HEADER_SIZE);
+       compressmeta = z_erofs_write_indexes(ictx);
        if (!compressmeta) {
                ret = -ENOMEM;
                goto err_free_idata;
        }
-       ictx->metacur = compressmeta + Z_EROFS_LEGACY_MAP_HEADER_SIZE;
-       z_erofs_write_indexes(ictx);
 
        legacymetasize = ictx->metacur - compressmeta;
        /* estimate if data compression saves space or not */
@@ -1164,7 +1171,6 @@ int erofs_commit_compressed_file(struct z_erofs_compress_ictx *ictx,
                goto err_free_meta;
        }
        z_erofs_dedupe_commit(false);
-       z_erofs_write_mapheader(inode, compressmeta);
 
        if (!ictx->fragemitted)
                sbi->saved_by_deduplication += inode->fragment_size;