From: "Theodore Ts'o" Subject: [PATCH, e2fsprogs] libext2fs: Add ext2fs_block_iterate3() which has 64-bit support Date: Fri, 10 Oct 2008 16:43:43 -0400 Message-ID: Cc: linux-ext4@vger.kernel.org To: Valerie Aurora Henson Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:49755 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758159AbYJJUnp (ORCPT ); Fri, 10 Oct 2008 16:43:45 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: There was discussion about how to do 64-bit ABI conversation, and an assertion that it might be hard to do ext2fs_block_iterate3. So I decided give an example of how I believe the most efficient way to do this sort of thing. Each interface when coverted over to 64-bit should be its own patch; for example, this one adds a new 64-bit version of ext2fs_block_iterate3. The patch simply modified ext2fs_block_iterate2() to be ext2fs_block_iterate3(), changing types as needed. I then created a backwards compatibility function for ext2fs_block_iterate2() which calls ext2fs_block_iterate3(). Total time to create the initial version of the patch was about 10 minutes. I then ran it through the (32-bit only) regression test, which flagged some failures because I didn't quite do the first version of the patch correctly. (I started the patch by doing a global search and replace of blk_t with blk64_t, and that screwed up the code which depended on the on-disk format of an indirect block really being a 32-bit blk_t.) Total time for a tested, functional patch was about 30 minutes. - Ted commit 54f130e7623a2a5affb0c27f5f4a42d8ace3acea Author: Theodore Ts'o Date: Fri Oct 10 16:36:22 2008 -0400 libext2fs: Add ext2fs_block_iterate3() which has 64-bit support Signed-off-by: "Theodore Ts'o" diff --git a/lib/ext2fs/block.c b/lib/ext2fs/block.c index b19c450..eafb4cb 100644 --- a/lib/ext2fs/block.c +++ b/lib/ext2fs/block.c @@ -21,9 +21,9 @@ struct block_context { ext2_filsys fs; int (*func)(ext2_filsys fs, - blk_t *blocknr, + blk64_t *blocknr, e2_blkcnt_t bcount, - blk_t ref_blk, + blk64_t ref_blk, int ref_offset, void *priv_data); e2_blkcnt_t bcount; @@ -62,13 +62,17 @@ static int block_iterate_ind(blk_t *ind_block, blk_t ref_block, int ret = 0, changed = 0; int i, flags, limit, offset; blk_t *block_nr; + blk64_t blk64; limit = ctx->fs->blocksize >> 2; if (!(ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && - !(ctx->flags & BLOCK_FLAG_DATA_ONLY)) - ret = (*ctx->func)(ctx->fs, ind_block, + !(ctx->flags & BLOCK_FLAG_DATA_ONLY)) { + blk64 = *ind_block; + ret = (*ctx->func)(ctx->fs, &blk64, BLOCK_COUNT_IND, ref_block, ref_offset, ctx->priv_data); + *ind_block = blk64; + } check_for_ro_violation_return(ctx, ret); if (!*ind_block || (ret & BLOCK_ABORT)) { ctx->bcount += limit; @@ -91,9 +95,11 @@ static int block_iterate_ind(blk_t *ind_block, blk_t ref_block, offset = 0; if (ctx->flags & BLOCK_FLAG_APPEND) { for (i = 0; i < limit; i++, ctx->bcount++, block_nr++) { - flags = (*ctx->func)(ctx->fs, block_nr, ctx->bcount, + blk64 = *block_nr; + flags = (*ctx->func)(ctx->fs, &blk64, ctx->bcount, *ind_block, offset, ctx->priv_data); + *block_nr = blk64; changed |= flags; if (flags & BLOCK_ABORT) { ret |= BLOCK_ABORT; @@ -105,9 +111,11 @@ static int block_iterate_ind(blk_t *ind_block, blk_t ref_block, for (i = 0; i < limit; i++, ctx->bcount++, block_nr++) { if (*block_nr == 0) continue; - flags = (*ctx->func)(ctx->fs, block_nr, ctx->bcount, + blk64 = *block_nr; + flags = (*ctx->func)(ctx->fs, &blk64, ctx->bcount, *ind_block, offset, ctx->priv_data); + *block_nr = blk64; changed |= flags; if (flags & BLOCK_ABORT) { ret |= BLOCK_ABORT; @@ -125,10 +133,13 @@ static int block_iterate_ind(blk_t *ind_block, blk_t ref_block, } if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && !(ctx->flags & BLOCK_FLAG_DATA_ONLY) && - !(ret & BLOCK_ABORT)) - ret |= (*ctx->func)(ctx->fs, ind_block, + !(ret & BLOCK_ABORT)) { + blk64 = *ind_block; + ret |= (*ctx->func)(ctx->fs, &blk64, BLOCK_COUNT_IND, ref_block, ref_offset, ctx->priv_data); + *ind_block = blk64; + } check_for_ro_violation_return(ctx, ret); return ret; } @@ -139,13 +150,17 @@ static int block_iterate_dind(blk_t *dind_block, blk_t ref_block, int ret = 0, changed = 0; int i, flags, limit, offset; blk_t *block_nr; + blk64_t blk64; limit = ctx->fs->blocksize >> 2; if (!(ctx->flags & (BLOCK_FLAG_DEPTH_TRAVERSE | - BLOCK_FLAG_DATA_ONLY))) - ret = (*ctx->func)(ctx->fs, dind_block, + BLOCK_FLAG_DATA_ONLY))) { + blk64 = *dind_block; + ret = (*ctx->func)(ctx->fs, &blk64, BLOCK_COUNT_DIND, ref_block, ref_offset, ctx->priv_data); + *dind_block = blk64; + } check_for_ro_violation_return(ctx, ret); if (!*dind_block || (ret & BLOCK_ABORT)) { ctx->bcount += limit*limit; @@ -204,10 +219,13 @@ static int block_iterate_dind(blk_t *dind_block, blk_t ref_block, } if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && !(ctx->flags & BLOCK_FLAG_DATA_ONLY) && - !(ret & BLOCK_ABORT)) - ret |= (*ctx->func)(ctx->fs, dind_block, + !(ret & BLOCK_ABORT)) { + blk64 = *dind_block; + ret |= (*ctx->func)(ctx->fs, &blk64, BLOCK_COUNT_DIND, ref_block, ref_offset, ctx->priv_data); + *dind_block = blk64; + } check_for_ro_violation_return(ctx, ret); return ret; } @@ -218,13 +236,17 @@ static int block_iterate_tind(blk_t *tind_block, blk_t ref_block, int ret = 0, changed = 0; int i, flags, limit, offset; blk_t *block_nr; + blk64_t blk64; limit = ctx->fs->blocksize >> 2; if (!(ctx->flags & (BLOCK_FLAG_DEPTH_TRAVERSE | - BLOCK_FLAG_DATA_ONLY))) - ret = (*ctx->func)(ctx->fs, tind_block, + BLOCK_FLAG_DATA_ONLY))) { + blk64 = *tind_block; + ret = (*ctx->func)(ctx->fs, &blk64, BLOCK_COUNT_TIND, ref_block, ref_offset, ctx->priv_data); + *tind_block = blk64; + } check_for_ro_violation_return(ctx, ret); if (!*tind_block || (ret & BLOCK_ABORT)) { ctx->bcount += limit*limit*limit; @@ -283,22 +305,25 @@ static int block_iterate_tind(blk_t *tind_block, blk_t ref_block, } if ((ctx->flags & BLOCK_FLAG_DEPTH_TRAVERSE) && !(ctx->flags & BLOCK_FLAG_DATA_ONLY) && - !(ret & BLOCK_ABORT)) - ret |= (*ctx->func)(ctx->fs, tind_block, + !(ret & BLOCK_ABORT)) { + blk64 = *tind_block; + ret |= (*ctx->func)(ctx->fs, &blk64, BLOCK_COUNT_TIND, ref_block, ref_offset, ctx->priv_data); + *tind_block = blk64; + } check_for_ro_violation_return(ctx, ret); return ret; } -errcode_t ext2fs_block_iterate2(ext2_filsys fs, +errcode_t ext2fs_block_iterate3(ext2_filsys fs, ext2_ino_t ino, int flags, char *block_buf, int (*func)(ext2_filsys fs, - blk_t *blocknr, + blk64_t *blocknr, e2_blkcnt_t blockcnt, - blk_t ref_blk, + blk64_t ref_blk, int ref_offset, void *priv_data), void *priv_data) @@ -309,6 +334,7 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs, errcode_t retval; struct block_context ctx; int limit; + blk64_t blk64; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); @@ -348,10 +374,11 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs, if ((fs->super->s_creator_os == EXT2_OS_HURD) && !(flags & BLOCK_FLAG_DATA_ONLY)) { if (inode.osd1.hurd1.h_i_translator) { - ret |= (*ctx.func)(fs, - &inode.osd1.hurd1.h_i_translator, + blk64 = inode.osd1.hurd1.h_i_translator; + ret |= (*ctx.func)(fs, &blk64, BLOCK_COUNT_TRANSLATOR, 0, 0, priv_data); + inode.osd1.hurd1.h_i_translator = (blk_t) blk64; if (ret & BLOCK_ABORT) goto abort_exit; check_for_ro_violation_goto(&ctx, ret, abort_exit); @@ -362,7 +389,7 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs, ext2_extent_handle_t handle; struct ext2fs_extent extent; e2_blkcnt_t blockcnt = 0; - blk_t blk, new_blk; + blk64_t blk, new_blk; int op = EXT2_EXTENT_ROOT; unsigned int j; @@ -432,7 +459,7 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs, ctx.errcode = ext2fs_extent_set_bmap(handle, (blk64_t) blockcnt, - (blk64_t) new_blk, 0); + new_blk, 0); if (ctx.errcode) break; } @@ -452,15 +479,17 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs, */ for (i = 0; i < EXT2_NDIR_BLOCKS ; i++, ctx.bcount++) { if (inode.i_block[i] || (flags & BLOCK_FLAG_APPEND)) { - ret |= (*ctx.func)(fs, &inode.i_block[i], - ctx.bcount, 0, i, priv_data); + blk64 = inode.i_block[i]; + ret |= (*ctx.func)(fs, &blk64, ctx.bcount, 0, i, + priv_data); + inode.i_block[i] = (blk_t) blk64; if (ret & BLOCK_ABORT) goto abort_exit; } } check_for_ro_violation_goto(&ctx, ret, abort_exit); if (inode.i_block[EXT2_IND_BLOCK] || (flags & BLOCK_FLAG_APPEND)) { - ret |= block_iterate_ind(&inode.i_block[EXT2_IND_BLOCK], + ret |= block_iterate_ind(&inode.i_block[EXT2_IND_BLOCK], 0, EXT2_IND_BLOCK, &ctx); if (ret & BLOCK_ABORT) goto abort_exit; @@ -497,6 +526,52 @@ errout: * Emulate the old ext2fs_block_iterate function! */ +struct xlate64 { + int (*func)(ext2_filsys fs, + blk_t *blocknr, + e2_blkcnt_t blockcnt, + blk_t ref_blk, + int ref_offset, + void *priv_data); + void *real_private; +}; + +static int xlate64_func(ext2_filsys fs, blk64_t *blocknr, + e2_blkcnt_t blockcnt, blk64_t ref_blk, + int ref_offset, void *priv_data) +{ + struct xlate64 *xl = (struct xlate64 *) priv_data; + int ret; + blk_t block32 = *blocknr; + + ret = (*xl->func)(fs, &block32, blockcnt, (blk_t) ref_blk, ref_offset, + xl->real_private); + *blocknr = block32; + return ret; +} + +errcode_t ext2fs_block_iterate2(ext2_filsys fs, + ext2_ino_t ino, + int flags, + char *block_buf, + int (*func)(ext2_filsys fs, + blk_t *blocknr, + e2_blkcnt_t blockcnt, + blk_t ref_blk, + int ref_offset, + void *priv_data), + void *priv_data) +{ + struct xlate64 xl; + + xl.real_private = priv_data; + xl.func = func; + + return ext2fs_block_iterate3(fs, ino, flags, block_buf, + xlate64_func, &xl); +} + + struct xlate { int (*func)(ext2_filsys fs, blk_t *blocknr, diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h index e02a55f..aa58c23 100644 --- a/lib/ext2fs/ext2fs.h +++ b/lib/ext2fs/ext2fs.h @@ -703,6 +703,17 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs, int ref_offset, void *priv_data), void *priv_data); +errcode_t ext2fs_block_iterate3(ext2_filsys fs, + ext2_ino_t ino, + int flags, + char *block_buf, + int (*func)(ext2_filsys fs, + blk64_t *blocknr, + e2_blkcnt_t blockcnt, + blk64_t ref_blk, + int ref_offset, + void *priv_data), + void *priv_data); /* bmap.c */ extern errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino,