Use STACK_MAX

[wimlib] / src / ntfs-3g_capture.c

diff --git a/src/ntfs-3g_capture.c b/src/ntfs-3g_capture.c
index c674cca9729db575d79da5183c4e61920f25d861..6daf0a54720afaa2a31bb1a75bfbc4546c213d1f 100644 (file)
--- a/src/ntfs-3g_capture.c
+++ b/src/ntfs-3g_capture.c
@@ -78,6 +78,7 @@ int
 read_ntfs_file_prefix(const struct wim_lookup_table_entry *lte,
                      u64 size,
                      consume_data_callback_t cb,
+                     u32 in_chunk_size,
                      void *ctx_or_buf,
                      int _ignored_flags)
 {
@@ -88,6 +89,7 @@ read_ntfs_file_prefix(const struct wim_lookup_table_entry *lte,
        s64 pos;
        s64 bytes_remaining;
        void *out_buf;
+       bool out_buf_malloced;
        int ret;
 
        ni = ntfs_pathname_to_inode(vol, NULL, loc->path);
@@ -103,30 +105,44 @@ read_ntfs_file_prefix(const struct wim_lookup_table_entry *lte,
                goto out_close_ntfs_inode;
        }
 
-       if (cb)
-               out_buf = alloca(WIM_CHUNK_SIZE);
-       else
+       out_buf_malloced = false;
+       if (cb) {
+               if (in_chunk_size <= STACK_MAX) {
+                       out_buf = alloca(in_chunk_size);
+               } else {
+                       out_buf = MALLOC(in_chunk_size);
+                       if (out_buf == NULL) {
+                               ret = WIMLIB_ERR_NOMEM;
+                               goto out_close_ntfs_attr;
+                       }
+                       out_buf_malloced = true;
+               }
+       } else {
                out_buf = ctx_or_buf;
+       }
        pos = (loc->is_reparse_point) ? 8 : 0;
        bytes_remaining = size;
        while (bytes_remaining) {
-               s64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE);
+               s64 to_read = min(bytes_remaining, in_chunk_size);
                if (ntfs_attr_pread(na, pos, to_read, out_buf) != to_read) {
                        ERROR_WITH_ERRNO("Error reading \"%"TS"\"", loc->path);
                        ret = WIMLIB_ERR_NTFS_3G;
-                       goto out_close_ntfs_attr;
+                       goto out_free_memory;
                }
                pos += to_read;
                bytes_remaining -= to_read;
                if (cb) {
                        ret = cb(out_buf, to_read, ctx_or_buf);
                        if (ret)
-                               goto out_close_ntfs_attr;
+                               goto out_free_memory;
                } else {
                        out_buf += to_read;
                }
        }
        ret = 0;
+out_free_memory:
+       if (out_buf_malloced)
+               FREE(out_buf);
 out_close_ntfs_attr:
        ntfs_attr_close(na);
 out_close_ntfs_inode: