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Message-ID: <20131126064445.GA20867@gmail.com>
Date: Tue, 26 Nov 2013 14:44:45 +0800
From: Zheng Liu <gnehzuil.liu@...il.com>
To: "Darrick J. Wong" <darrick.wong@...cle.com>
Cc: tytso@....edu, linux-ext4@...r.kernel.org
Subject: Re: [PATCH 16/25] resize2fs: convert fs to and from 64bit mode
On Thu, Oct 17, 2013 at 09:50:42PM -0700, Darrick J. Wong wrote:
> resize2fs does its magic by loading a filesystem, duplicating the
> in-memory image of that fs, moving relevant blocks out of the way of
> whatever new metadata get created, and finally writing everything back
> out to disk. Enabling 64bit mode enlarges the group descriptors,
> which makes resize2fs a reasonable vehicle for taking care of the rest
> of the bookkeeping requirements, so add to resize2fs the ability to
> convert a filesystem to 64bit mode and back.
Sorry, I don't get your point why we need to add these arguments to
enable/disable 64bit mode. If I understand correctly, we don't disable
64bit mode for a file system which is larger than 2^32 blocks. So that
means that we just disable it for a file system which 64bit shouldn't be
enabled. Is it worth doing this?
Otherwise one nit below.
- Zheng
>
> Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com>
> ---
> resize/main.c | 40 ++++++-
> resize/resize2fs.8.in | 18 +++
> resize/resize2fs.c | 282 ++++++++++++++++++++++++++++++++++++++++++++++++-
> resize/resize2fs.h | 3 +
> 4 files changed, 336 insertions(+), 7 deletions(-)
>
>
> diff --git a/resize/main.c b/resize/main.c
> index 1394ae1..ad0c946 100644
> --- a/resize/main.c
> +++ b/resize/main.c
> @@ -41,7 +41,7 @@ char *program_name, *device_name, *io_options;
> static void usage (char *prog)
> {
> fprintf (stderr, _("Usage: %s [-d debug_flags] [-f] [-F] [-M] [-P] "
> - "[-p] device [new_size]\n\n"), prog);
> + "[-p] device [-b|-s|new_size]\n\n"), prog);
>
> exit (1);
> }
> @@ -199,7 +199,7 @@ int main (int argc, char ** argv)
> if (argc && *argv)
> program_name = *argv;
>
> - while ((c = getopt (argc, argv, "d:fFhMPpS:")) != EOF) {
> + while ((c = getopt(argc, argv, "d:fFhMPpS:bs")) != EOF) {
> switch (c) {
> case 'h':
> usage(program_name);
> @@ -225,6 +225,12 @@ int main (int argc, char ** argv)
> case 'S':
> use_stride = atoi(optarg);
> break;
> + case 'b':
> + flags |= RESIZE_ENABLE_64BIT;
> + break;
> + case 's':
> + flags |= RESIZE_DISABLE_64BIT;
> + break;
> default:
> usage(program_name);
> }
> @@ -383,6 +389,10 @@ int main (int argc, char ** argv)
> if (sys_page_size > fs->blocksize)
> new_size &= ~((sys_page_size / fs->blocksize)-1);
> }
> + /* If changing 64bit, don't change the filesystem size. */
> + if (flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)) {
> + new_size = ext2fs_blocks_count(fs->super);
> + }
> if (!EXT2_HAS_INCOMPAT_FEATURE(fs->super,
> EXT4_FEATURE_INCOMPAT_64BIT)) {
> /* Take 16T down to 2^32-1 blocks */
> @@ -434,7 +444,31 @@ int main (int argc, char ** argv)
> fs->blocksize / 1024, new_size);
> exit(1);
> }
> - if (new_size == ext2fs_blocks_count(fs->super)) {
> + if (flags & RESIZE_DISABLE_64BIT && flags & RESIZE_ENABLE_64BIT) {
^^^^^
Coding style problem:
if ((flags & RESIZE_ENABLE_64BIT) && (flags & RESIZE_ENABLE_64BIT))
> + fprintf(stderr, _("Cannot set and unset 64bit feature.\n"));
> + exit(1);
> + } else if (flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)) {
> + new_size = ext2fs_blocks_count(fs->super);
> + if (new_size >= (1ULL << 32)) {
> + fprintf(stderr, _("Cannot change the 64bit feature "
> + "on a filesystem that is larger than "
> + "2^32 blocks.\n"));
> + exit(1);
> + }
> + if (mount_flags & EXT2_MF_MOUNTED) {
> + fprintf(stderr, _("Cannot change the 64bit feature "
> + "while the filesystem is mounted.\n"));
> + exit(1);
> + }
> + if (flags & RESIZE_ENABLE_64BIT &&
^^^^
ditto
> + !EXT2_HAS_INCOMPAT_FEATURE(fs->super,
> + EXT3_FEATURE_INCOMPAT_EXTENTS)) {
> + fprintf(stderr, _("Please enable the extents feature "
> + "with tune2fs before enabling the 64bit "
> + "feature.\n"));
> + exit(1);
> + }
> + } else if (new_size == ext2fs_blocks_count(fs->super)) {
> fprintf(stderr, _("The filesystem is already %llu blocks "
> "long. Nothing to do!\n\n"), new_size);
> exit(0);
> diff --git a/resize/resize2fs.8.in b/resize/resize2fs.8.in
> index a1f3099..1c75816 100644
> --- a/resize/resize2fs.8.in
> +++ b/resize/resize2fs.8.in
> @@ -8,7 +8,7 @@ resize2fs \- ext2/ext3/ext4 file system resizer
> .SH SYNOPSIS
> .B resize2fs
> [
> -.B \-fFpPM
> +.B \-fFpPMbs
> ]
> [
> .B \-d
> @@ -85,8 +85,21 @@ to shrink the size of filesystem. Then you may use
> to shrink the size of the partition. When shrinking the size of
> the partition, make sure you do not make it smaller than the new size
> of the ext2 filesystem!
> +.PP
> +The
> +.B \-b
> +and
> +.B \-s
> +options enable and disable the 64bit feature, respectively. The resize2fs
> +program will, of course, take care of resizing the block group descriptors
> +and moving other data blocks out of the way, as needed. It is not possible
> +to resize the filesystem concurrent with changing the 64bit status.
> .SH OPTIONS
> .TP
> +.B \-b
> +Turns on the 64bit feature, resizes the group descriptors as necessary, and
> +moves other metadata out of the way.
> +.TP
> .B \-d \fIdebug-flags
> Turns on various resize2fs debugging features, if they have been compiled
> into the binary.
> @@ -126,6 +139,9 @@ of what the program is doing.
> .B \-P
> Print the minimum size of the filesystem and exit.
> .TP
> +.B \-s
> +Turns off the 64bit feature and frees blocks that are no longer in use.
> +.TP
> .B \-S \fIRAID-stride
> The
> .B resize2fs
> diff --git a/resize/resize2fs.c b/resize/resize2fs.c
> index 0feff0f..05ba6e1 100644
> --- a/resize/resize2fs.c
> +++ b/resize/resize2fs.c
> @@ -53,6 +53,9 @@ static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
> static errcode_t fix_sb_journal_backup(ext2_filsys fs);
> static errcode_t mark_table_blocks(ext2_filsys fs,
> ext2fs_block_bitmap bmap);
> +static errcode_t resize_group_descriptors(ext2_resize_t rfs, blk64_t new_size);
> +static errcode_t move_bg_metadata(ext2_resize_t rfs);
> +static errcode_t zero_high_bits_in_inodes(ext2_resize_t rfs);
>
> /*
> * Some helper CPP macros
> @@ -119,13 +122,30 @@ errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
> if (retval)
> goto errout;
>
> + init_resource_track(&rtrack, "resize_group_descriptors", fs->io);
> + retval = resize_group_descriptors(rfs, *new_size);
> + if (retval)
> + goto errout;
> + print_resource_track(rfs, &rtrack, fs->io);
> +
> + init_resource_track(&rtrack, "move_bg_metadata", fs->io);
> + retval = move_bg_metadata(rfs);
> + if (retval)
> + goto errout;
> + print_resource_track(rfs, &rtrack, fs->io);
> +
> + init_resource_track(&rtrack, "zero_high_bits_in_metadata", fs->io);
> + retval = zero_high_bits_in_inodes(rfs);
> + if (retval)
> + goto errout;
> + print_resource_track(rfs, &rtrack, fs->io);
> +
> init_resource_track(&rtrack, "adjust_superblock", fs->io);
> retval = adjust_superblock(rfs, *new_size);
> if (retval)
> goto errout;
> print_resource_track(rfs, &rtrack, fs->io);
>
> -
> init_resource_track(&rtrack, "fix_uninit_block_bitmaps 2", fs->io);
> fix_uninit_block_bitmaps(rfs->new_fs);
> print_resource_track(rfs, &rtrack, fs->io);
> @@ -221,6 +241,259 @@ errout:
> return retval;
> }
>
> +/* Toggle 64bit mode */
> +static errcode_t resize_group_descriptors(ext2_resize_t rfs, blk64_t new_size)
> +{
> + void *o, *n, *new_group_desc;
> + dgrp_t i;
> + int copy_size;
> + errcode_t retval;
> +
> + if (!(rfs->flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)))
> + return 0;
> +
> + if (new_size != ext2fs_blocks_count(rfs->new_fs->super) ||
> + ext2fs_blocks_count(rfs->new_fs->super) >= (1ULL << 32) ||
> + (rfs->flags & RESIZE_DISABLE_64BIT &&
> + rfs->flags & RESIZE_ENABLE_64BIT))
> + return EXT2_ET_INVALID_ARGUMENT;
> +
> + if (rfs->flags & RESIZE_DISABLE_64BIT) {
> + rfs->new_fs->super->s_feature_incompat &=
> + ~EXT4_FEATURE_INCOMPAT_64BIT;
> + rfs->new_fs->super->s_desc_size = EXT2_MIN_DESC_SIZE;
> + } else if (rfs->flags & RESIZE_ENABLE_64BIT) {
> + rfs->new_fs->super->s_feature_incompat |=
> + EXT4_FEATURE_INCOMPAT_64BIT;
> + rfs->new_fs->super->s_desc_size = EXT2_MIN_DESC_SIZE_64BIT;
> + }
> +
> + if (EXT2_DESC_SIZE(rfs->old_fs->super) ==
> + EXT2_DESC_SIZE(rfs->new_fs->super))
> + return 0;
> +
> + o = rfs->new_fs->group_desc;
> + rfs->new_fs->desc_blocks = ext2fs_div_ceil(
> + rfs->old_fs->group_desc_count,
> + EXT2_DESC_PER_BLOCK(rfs->new_fs->super));
> + retval = ext2fs_get_arrayzero(rfs->new_fs->desc_blocks,
> + rfs->old_fs->blocksize, &new_group_desc);
> + if (retval)
> + return retval;
> +
> + n = new_group_desc;
> +
> + if (EXT2_DESC_SIZE(rfs->old_fs->super) <=
> + EXT2_DESC_SIZE(rfs->new_fs->super))
> + copy_size = EXT2_DESC_SIZE(rfs->old_fs->super);
> + else
> + copy_size = EXT2_DESC_SIZE(rfs->new_fs->super);
> + for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
> + memcpy(n, o, copy_size);
> + n += EXT2_DESC_SIZE(rfs->new_fs->super);
> + o += EXT2_DESC_SIZE(rfs->old_fs->super);
> + }
> +
> + ext2fs_free_mem(&rfs->new_fs->group_desc);
> + rfs->new_fs->group_desc = new_group_desc;
> +
> + for (i = 0; i < rfs->old_fs->group_desc_count; i++)
> + ext2fs_group_desc_csum_set(rfs->new_fs, i);
> +
> + return 0;
> +}
> +
> +/* Move bitmaps/inode tables out of the way. */
> +static errcode_t move_bg_metadata(ext2_resize_t rfs)
> +{
> + dgrp_t i;
> + blk64_t b, c, d;
> + ext2fs_block_bitmap old_map, new_map;
> + int old, new;
> + errcode_t retval;
> + int zero = 0, one = 1;
> +
> + if (!(rfs->flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)))
> + return 0;
> +
> + retval = ext2fs_allocate_block_bitmap(rfs->old_fs, "oldfs", &old_map);
> + if (retval)
> + return retval;
> +
> + retval = ext2fs_allocate_block_bitmap(rfs->new_fs, "newfs", &new_map);
> + if (retval)
> + goto out;
> +
> + /* Construct bitmaps of super/descriptor blocks in old and new fs */
> + for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
> + retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, i, &b, &c, &d,
> + NULL);
> + if (retval)
> + goto out;
> + ext2fs_mark_block_bitmap2(old_map, b);
> + ext2fs_mark_block_bitmap2(old_map, c);
> + ext2fs_mark_block_bitmap2(old_map, d);
> +
> + retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, i, &b, &c, &d,
> + NULL);
> + if (retval)
> + goto out;
> + ext2fs_mark_block_bitmap2(new_map, b);
> + ext2fs_mark_block_bitmap2(new_map, c);
> + ext2fs_mark_block_bitmap2(new_map, d);
> + }
> +
> + /* Find changes in block allocations for bg metadata */
> + for (b = 0;
> + b < ext2fs_blocks_count(rfs->new_fs->super);
> + b += EXT2FS_CLUSTER_RATIO(rfs->new_fs)) {
> + old = ext2fs_test_block_bitmap2(old_map, b);
> + new = ext2fs_test_block_bitmap2(new_map, b);
> +
> + if (old && !new)
> + ext2fs_unmark_block_bitmap2(rfs->new_fs->block_map, b);
> + else if (!old && new)
> + ; /* empty ext2fs_mark_block_bitmap2(new_map, b); */
> + else
> + ext2fs_unmark_block_bitmap2(new_map, b);
> + }
> + /* new_map now shows blocks that have been newly allocated. */
> +
> + /* Move any conflicting bitmaps and inode tables */
> + for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
> + b = ext2fs_block_bitmap_loc(rfs->new_fs, i);
> + if (ext2fs_test_block_bitmap2(new_map, b))
> + ext2fs_block_bitmap_loc_set(rfs->new_fs, i, 0);
> +
> + b = ext2fs_inode_bitmap_loc(rfs->new_fs, i);
> + if (ext2fs_test_block_bitmap2(new_map, b))
> + ext2fs_inode_bitmap_loc_set(rfs->new_fs, i, 0);
> +
> + c = ext2fs_inode_table_loc(rfs->new_fs, i);
> + for (b = 0; b < rfs->new_fs->inode_blocks_per_group; b++) {
> + if (ext2fs_test_block_bitmap2(new_map, b + c)) {
> + ext2fs_inode_table_loc_set(rfs->new_fs, i, 0);
> + break;
> + }
> + }
> + }
> +
> +out:
> + if (old_map)
> + ext2fs_free_block_bitmap(old_map);
> + if (new_map)
> + ext2fs_free_block_bitmap(new_map);
> + return retval;
> +}
> +
> +/* Zero out the high bits of extent fields */
> +static errcode_t zero_high_bits_in_extents(ext2_filsys fs, ext2_ino_t ino,
> + struct ext2_inode *inode)
> +{
> + ext2_extent_handle_t handle;
> + struct ext2fs_extent extent;
> + int op = EXT2_EXTENT_ROOT;
> + errcode_t errcode;
> +
> + if (!(inode->i_flags & EXT4_EXTENTS_FL))
> + return 0;
> +
> + errcode = ext2fs_extent_open(fs, ino, &handle);
> + if (errcode)
> + return errcode;
> +
> + while (1) {
> + errcode = ext2fs_extent_get(handle, op, &extent);
> + if (errcode)
> + break;
> +
> + op = EXT2_EXTENT_NEXT_SIB;
> +
> + if (extent.e_pblk > (1ULL << 32)) {
> + extent.e_pblk &= (1ULL << 32) - 1;
> + errcode = ext2fs_extent_replace(handle, 0, &extent);
> + if (errcode)
> + break;
> + }
> + }
> +
> + /* Ok if we run off the end */
> + if (errcode == EXT2_ET_EXTENT_NO_NEXT)
> + errcode = 0;
> + return errcode;
> +}
> +
> +/* Zero out the high bits of inodes. */
> +static errcode_t zero_high_bits_in_inodes(ext2_resize_t rfs)
> +{
> + ext2_filsys fs = rfs->new_fs;
> + int length = EXT2_INODE_SIZE(fs->super);
> + struct ext2_inode *inode = NULL;
> + ext2_inode_scan scan = NULL;
> + errcode_t retval;
> + ext2_ino_t ino;
> + blk64_t file_acl_block;
> + int inode_dirty;
> +
> + if (!(rfs->flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)))
> + return 0;
> +
> + if (fs->super->s_creator_os != EXT2_OS_LINUX)
> + return 0;
> +
> + retval = ext2fs_open_inode_scan(fs, 0, &scan);
> + if (retval)
> + return retval;
> +
> + retval = ext2fs_get_mem(length, &inode);
> + if (retval)
> + goto out;
> +
> + do {
> + retval = ext2fs_get_next_inode_full(scan, &ino, inode, length);
> + if (retval)
> + goto out;
> + if (!ino)
> + break;
> + if (!ext2fs_test_inode_bitmap2(fs->inode_map, ino))
> + continue;
> +
> + /*
> + * Here's how we deal with high block number fields:
> + *
> + * - i_size_high has been been written out with i_size_lo
> + * since the ext2 days, so no conversion is needed.
> + *
> + * - i_blocks_hi is guarded by both the huge_file feature and
> + * inode flags and has always been written out with
> + * i_blocks_lo if the feature is set. The field is only
> + * ever read if both feature and inode flag are set, so
> + * we don't need to zero it now.
> + *
> + * - i_file_acl_high can be uninitialized, so zero it if
> + * it isn't already.
> + */
> + if (inode->osd2.linux2.l_i_file_acl_high) {
> + inode->osd2.linux2.l_i_file_acl_high = 0;
> + retval = ext2fs_write_inode_full(fs, ino, inode,
> + length);
> + if (retval)
> + goto out;
> + }
> +
> + retval = zero_high_bits_in_extents(fs, ino, inode);
> + if (retval)
> + goto out;
> + } while (ino);
> +
> +out:
> + if (inode)
> + ext2fs_free_mem(&inode);
> + if (scan)
> + ext2fs_close_inode_scan(scan);
> + return retval;
> +}
> +
> /*
> * Clean up the bitmaps for unitialized bitmaps
> */
> @@ -424,7 +697,8 @@ retry:
> /*
> * Reallocate the group descriptors as necessary.
> */
> - if (old_fs->desc_blocks != fs->desc_blocks) {
> + if (EXT2_DESC_SIZE(old_fs->super) == EXT2_DESC_SIZE(fs->super) &&
> + old_fs->desc_blocks != fs->desc_blocks) {
> retval = ext2fs_resize_mem(old_fs->desc_blocks *
> fs->blocksize,
> fs->desc_blocks * fs->blocksize,
> @@ -949,7 +1223,9 @@ static errcode_t blocks_to_move(ext2_resize_t rfs)
> new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
> }
>
> - if (old_blocks == new_blocks) {
> + if (EXT2_DESC_SIZE(rfs->old_fs->super) ==
> + EXT2_DESC_SIZE(rfs->new_fs->super) &&
> + old_blocks == new_blocks) {
> retval = 0;
> goto errout;
> }
> diff --git a/resize/resize2fs.h b/resize/resize2fs.h
> index 52319b5..5a1c5dc 100644
> --- a/resize/resize2fs.h
> +++ b/resize/resize2fs.h
> @@ -82,6 +82,9 @@ typedef struct ext2_sim_progress *ext2_sim_progmeter;
> #define RESIZE_PERCENT_COMPLETE 0x0100
> #define RESIZE_VERBOSE 0x0200
>
> +#define RESIZE_ENABLE_64BIT 0x0400
> +#define RESIZE_DISABLE_64BIT 0x0800
> +
> /*
> * This structure is used for keeping track of how much resources have
> * been used for a particular resize2fs pass.
>
> --
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