Commit Graph

125 Commits (e231f17500477f7abbea5c441971be491a04fdf4)

Author SHA1 Message Date
Theodore Ts'o e231f17500 resize2fs: add debugging support for resize2fs -M calcuations
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-09-30 22:12:22 -04:00
Darrick J. Wong 0851517daa resize2fs: use blk64_t and location getters for free_gdp_blocks()
free_gdp_blocks needs to be taught to use 64-bit fields and the appropriate
getters, otherwise it'll truncate high block numbers (when, say, resizing a
>16T fs) and mark the low numbered group descriptor blocks as free.  Yikes.

Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-09-09 10:40:48 -04:00
Eric Sandeen 80391dcd2e resize2fs: move bitmaps if shrinking would orphan them
It is possible to have a flex_bg filesystem with block groups
which have inode & block bitmaps at some point well past the
start of the group.

If an offline shrink puts the new size somewhere between
the start of the block group and the (old) location of
the bitmaps, they can be left beyond the end of the filesystem,
i.e. result in fs corruption.

Check each remaining block group for whether its bitmaps
are beyond the end of the new filesystem, and reallocate
them in a new location if needed.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2013-06-20 22:47:16 -04:00
Theodore Ts'o f026f1a370 resize2fs: fix off-line resize of file systems with flex_bg && !resize_inode
When doing an off-line resize2fs of an initially very small file
system, it's possible to run out of reserved gdt blocks (which are
reserved via the resize inode).  Once we run out, we need to move the
allocation bitmaps and inode table out of the way to grow the gdt
blocks.  Unfortunately, when moving these metadata blocks, it was
possible that a block that had been just been newly allocated for a
new block group could also get allocated for a metadata block for an
existing block group that was being moved.

To prevent this, after we grow the gdt blocks and allocate the
metadata blocks for the new block groups, make sure all of these
blocks are marked as reserved.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: John Jolly <john.jolly@gmail.com>
2013-03-31 20:40:57 -04:00
Theodore Ts'o d1a1a583c1 resize2fs: move a cluster at a time with bigalloc file systems
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-20 00:25:00 -05:00
Theodore Ts'o 1773c87c7e resize2fs: correctly account for clusters when calculating summary stats
Fixes resize2fs so it correctly calculates the number of free clusters
in each block group for file systems with the bigalloc feature
enabled.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-19 23:58:13 -05:00
Theodore Ts'o 027b0577d4 Fix 32-bit overflow problems: dgrp_t * s_blocks_per_group
There are a number of places where we multiply a dgrp_t with
s_blocks_per_group expecting that we will get a blk64_t.  This
requires a cast, or using the convenience function
ext2fs_group_first_block2().

This audit was suggested by Eric Sandeen.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2013-01-05 10:14:11 -05:00
Theodore Ts'o a0ba54ec00 resize2fs: use [un]mark_block_range bitmap functions to reduce CPU usage
Use ext2fs_[un]mark_block_range2() functions to reduce the CPU
overhead of resizing large file systems by 45%, primarily by
reducing the time spent in fix_uninit_block_bitmaps().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-03 09:03:53 -05:00
Theodore Ts'o 1eb31c4885 resize2fs: add resource tracking as a debug option
Add a new debug flag which prints how much time is consumed by the
various parts of resize2fs's processing.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-03 09:03:53 -05:00
Theodore Ts'o 2279fd78fe resize2fs: fix 32-bit overflow when calculating the number of free blocks
This caused the free blocks count in the superblock to be incorrect
after resizing a 64-bit file system if the number of free blocks
overflowed a 32-bit value.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-03 09:03:53 -05:00
Theodore Ts'o 5d3a88fbe9 resize2fs: fix 32-bit overflow issue which can corrupt 64-bit file systems
Fix a 32-bit overflow bug caused by a missing blk64_t cast which can
cause the block bitmap to get corrupted when doing an off-line resize
of a 64-bit file system.

This problem can be reproduced as follows:

rm -f foo.img; touch foo.img
truncate -s 8T foo.img
mke2fs -F -t ext4 -O 64bit foo.img
e2fsck -f foo.img
truncate -s 21T foo.img
resize2fs foo.img
e2fsck -fy foo.img

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-01-03 08:38:45 -05:00
Theodore Ts'o 831f309c62 resize2fs: create optimized flex_bg block groups
Now that we are reserving all of the bg-specific metadata before we
try to allocate the metadata for the new block groups, we don't have
to temporarily disable the flex_bg feature flag while we allocate the
new metadata blocks --- this allows the newly created block groups to
have a much more optimized layout, instead of fragmenting the inode
table and block/inode bitmaps in sepraate block groups.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-29 03:43:55 -05:00
Theodore Ts'o ddcf1dbff2 resize2fs: handle bg descriptors which overlap with other bg's metadata
With flex_bg file systems, bg-specific metadata (i.e., bitmaps and the
inode table blocks) can be located in another block group.  Hence,
when we grow the number of block group descriptors, we need to check
if we need to relocate metadata blocks not just for the block group
where the bgd blocks are located, but in all block groups.

This change fixes the following test case:

rm -f foo.img; touch foo.img
truncate -s 32G foo.img
mke2fs -F -t ext4 -E resize=12582912 foo.img
e2fsck -f foo.img
truncate -s 256G foo.img
./resize2fs foo.img
e2fsck -fy foo.img

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-29 03:25:10 -05:00
Theodore Ts'o 4b04fb30e0 resize2fs: reserve all metadata blocks for flex_bg file systems
For flex_bg file systems, if we need to relocate an allocation bitmap
or inode table, we need to make sure that all metadata blocks have
been reserved, lest we end up overwriting a metadata block belonging
to a different block group.

This change fixes the following test case:

rm -f foo.img; touch foo.img
truncate -s 32G foo.img
mke2fs -F -t ext4 -E resize=12582912 foo.img
e2fsck -f foo.img
truncate -s 64G foo.img
./resize2fs foo.img
e2fsck -fy foo.img

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-29 00:53:16 -05:00
Theodore Ts'o 2ebaeb35db resize2fs: reserve fs metadata blocks first in blocks_to_move()
This is the first commit to add support for off-line resizing using
flex_bg without the assist of using the resize_inode to reserve gdt
blocks.  This functionality has been broken up into separate commits
which are hopefully obviously correct to make them easier to review
for correctness.

In this first step, we break up the for loop at the end of
blocks_to_move() so that we first mark all of the metadata blocks
which don't need to be moved in the reserve_blocks bitmap, and then
try to allocate the metadata blocks are new or which need to moved
second.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-29 00:52:20 -05:00
Theodore Ts'o 5e27a274d3 resize2fs: fix gcc -Wall nits and valgrind complaints
One of these fixes was triggering failures when running:

./test_scripts --valgrind r_move_itable r_inline_xattr r_resize_inode

It should be a false positive, but it fixing this makes it easier to
see real problems.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-29 19:52:39 -05:00
Theodore Ts'o 2d8c0c8a4f resize2fs: grow uninit_bg file systems more efficiently
If the uninit_bg feature is enabled and the kernel supports
lazy_itable_init, skip zeroing the inode table so that the resize
operation can go much more quickly.  Also set the itable_unused fields
so that the first e2fsck after the resize will run faster.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-13 23:09:54 -04:00
Theodore Ts'o 7f82034438 resize2fs: fix overhead calculation for meta_bg file systems
The file system overhead calculation in calculate_minimum_resize_size
was incorrect meta_bg file systems.  This caused the minimum size to
underflow for very large file systems, which threw resize2fs into a
loop generally lasted longer than the user's patience.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-13 23:05:32 -04:00
Jan Kara ba8bfa1a6d resize2fs: take s_first_data_block into account for resize2fs -M
calculate_minimum_resize_size() forgot to account s_first_data_block
into minimum filesystem size. Thus in case the size of filesystem was
such that the last group had the minimal size (50 blocks + metadata
overhead), the code in adjust_fs_info() decided the group is unneeded,
removed it, and in some cases the resizing then failed with ENOSPC.

Fix the issue by properly accounting for s_first_data_block in
calculate_minimum_resize_size().

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2012-02-17 14:32:18 -05:00
Theodore Ts'o 0c80c44bd0 libext2fs: ext2fs_[set_]file_acl_block needs to check for 64-bit feature flag
The ext2fs_file_acl_block() and ext2fs_set_file_acl_block() needs to
only check i_file_acl_high if the 64-bit flag is set.  This is needed
because otherwise we will run into problems on Hurd systems which
actually use that field for h_i_mode_high.

This involves an ABI change since we need to pass ext2_filsys to these
functions.  Fortunately these functions were first included in the
1.42-WIP series, so it's OK for us to change them now.  (This is why
we have 1.42-WIP releases.  :-)

Addresses-Sourceforge-Bug: #3379227

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-16 20:46:49 -04:00
Theodore Ts'o 515e555a0c resize2fs: don't fail when shrinking an empty file system
This commit fixes a failure when running the commands:

dd if=/dev/zero of=fs bs=1k count=100k; mke2fs fs; resize2fs -Mp fs

We should not try truncating the file system if there is only a single
block group in the file system.

Addresses-Sourceforge-Bug: #3404051

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-10-16 19:29:40 -04:00
Theodore Ts'o d1154eb460 Shorten compile commands run by the build system
The DEFS line in MCONFIG had gotten so long that it exceeded 4k, and
this was starting to cause some tools heartburn.  It also made "make
V=1" almost useless, since trying to following the individual commands
run by make was lost in the noise of all of the defines.

So fix this by putting the configure-generated defines in lib/config.h
and the directory pathnames to lib/dirpaths.h.

In addition, clean up some vestigal defines in configure.in and in the
Makefiles to further shorten the cc command lines.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-18 17:34:37 -04:00
Eric Sandeen 98f4547198 e2fsprogs: add ext2fs_group_blocks_count helper
Code to count the number of blocks in the last partial
group is cut and pasted around the e2fsprogs codebase
a few times.

Making this a helper function should improve matters.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2011-09-16 09:28:43 -04:00
Andreas Dilger 931b58e1cb ext2fs: Handle internal journal over 2^32 bytes
The write_journal_inode() code is only setting the low 32-bit i_size
for the journal size, even though it is possible to specify a journal
up to 10M blocks in size.  Trying to create a journal larger than 2GB
will succeed, but an immediate e2fsck would fail.  Store i_size_high
for the journal inode when creating it, and load it upon access.

Use s_jnl_blocks[15] to store the journal i_size_high backup.  This
field is currently unused, as EXT2_N_BLOCKS is 15, so it is using
s_jnl_blocks[0..14], and i_size is in s_jnl_blocks[16].

Rename the "size" argument "num_blocks" for the journal creation functions
to clarify this parameter is in units of filesystem blocks and not bytes.

Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2011-06-11 12:17:29 -04:00
Theodore Ts'o 2696f2501c resize2fs: fix computation of the real end of the bitmap to be 64-bit
real_end had been previously declared with a bogus type, which is why
this was missed earlier.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-07 16:38:13 -05:00
Theodore Ts'o da2a5a4bae Merge branch 'maint' into next
Conflicts:
	resize/resize2fs.c
2010-12-22 19:00:21 -05:00
Eric Sandeen d16db7d9de resize2fs: do not clear resize inode for 0 resvd blocks
I ran into odd behavior where mkfs.ext4 of a 16T filesystem would
create a resize inode with 0 reserved blocks, and mark the resize_inode
feature.

A subsequent slight downward resize of the filesystem would remove
the resize inode, making any further offline resizing impossible.

This is especially odd in light of the fact that a large downward
resize (say, to 8T) will actually add blocks to the resize inode -
so a small resize removes it, a large resize expands it ...

commit 8ade268cf2 had added this:

  If the filesystem is grown to the point where the resize_inode is no
  longer needed, clean it up properly so e2fsck doesn't have to.

but, it seems e2fsck does not care about this situation, either.

So, simply leave the resize_inode intact in this case, and everything
seems to be happy.

Note, this is for the 1.41.xx branch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2010-12-22 13:54:30 -05:00
Valerie Aurora Henson 8728d50657 resize2fs: Fix up to be 64-bit block number safe
Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-13 18:00:00 -04:00
Theodore Ts'o cc84d866e2 Merge branch 'maint' into next
Conflicts:
	e2fsck/pass1.c
2010-02-10 18:20:58 -05:00
Theodore Ts'o 4828bbe9e7 resize2fs: Fix fix uninit group test accessing invalid memory
Commit 74128f8 added tests for uninit groups, but it could access past
the end of the group_desc[] array after processing the last group:

==19668== Invalid read of size 2
==19668==    at 0x40518C: resize_fs (resize2fs.c:1824)
==19668==    by 0x405A46: main (main.c:451)
==19668==  Address 0x5a0d002 is not stack'd, malloc'd or (recently) free'd
==19668==
==19668== Invalid read of size 2
==19668==    at 0x405391: resize_fs (resize2fs.c:1864)
==19668==    by 0x405A46: main (main.c:451)
==19668==  Address 0x5a0d002 is not stack'd, malloc'd or (recently) free'd
==19668==

It was found by Eric Sandeen running the regression suite through
valgrind.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-02-05 22:50:19 -05:00
Theodore Ts'o 4486af5b4c Merge branch 'maint' into next
Conflicts:
	misc/mke2fs.c
2009-11-16 00:30:57 -05:00
Eric Sandeen d93d5bbf60 resize2fs: exit fix_sb_journal_backup early for external journal
Resizing a filesystem with an external journal fails when it tries
to read inode 0:

# touch testfs
# truncate testfs 1342177280
# touch testjournal
# truncate testjournal 134217728
# mke2fs -O journal_dev testjournal
# losetup /dev/loop0 testjournal
# mkfs.ext4 -J device=/dev/loop0 testfs 127680
# resize2fs testfs
resize2fs 1.41.9 (22-Aug-2009)
Resizing the filesystem on testfs to 327680 (4k) blocks.
resize2fs: Illegal inode number while trying to resize testfs
Please run 'e2fsck -fy testfs' to fix the filesystem
after the aborted resize operation.

I think the right, simple thing to do is just bail out early
for an external journal here, as there are no backup blocks
to update.

Reported-by: mjevans1983@gmail.com
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2009-11-12 19:46:56 -05:00
Theodore Ts'o 6493f8e85d Convert ext2fs_group_of_blk() to ext2fs_group_of_blk2()
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-10-25 20:50:15 -04:00
Valerie Aurora Henson 48f23054bb Convert ext2fs_block_alloc_stats() calls to block_alloc_stats2()
Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-10-25 21:46:58 -04:00
Valerie Aurora Henson d7cca6b06f Convert to use block group accessor functions
Convert direct accesses to use the following block group accessor
functions: ext2fs_block_bitmap_loc(), ext2fs_inode_bitmap_loc(),
ext2fs_inode_table_loc(), ext2fs_bg_itable_unused(),
ext2fs_block_bitmap_loc_set(), ext2fs_inode_bitmap_loc_set(),
ext2fs_inode_table_loc_set(), ext2fs_bg_free_inodes_count(),
ext2fs_ext2fs_bg_used_dirs_count(), ext2fs_bg_free_inodes_count_set(),
ext2fs_bg_free_blocks_count_set(), ext2fs_bg_used_dirs_count_set()

Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: Nick Dokos <nicholas.dokos@hp.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-10-25 21:43:47 -04:00
Theodore Ts'o cd65a24e75 libext2fs: Convert ext2fs_bg_flag_test() to ext2fs_bg_flags_test()
After cleaning up ext2fs_bg_flag_set() and ext2fs_bg_flag_clear(),
we're left with ext2fs_bg_flag_test().  Convert it to
ext2fs_bg_flags_test().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-10-25 21:42:12 -04:00
Eric Sandeen e633b58ac7 libext2fs: clean up ext2fs_bg_flags_ interfaces
The ext2fs_bg_flag* functions were confusing.

Currently we have this:

void ext2fs_bg_flags_set(ext2_filsys fs, dgrp_t group, __u16 bg_flags);
void ext2fs_bg_flags_clear(ext2_filsys fs, dgrp_t group,__u16 bg_flags);

(_set (unused) sets exactly bg_flags; _clear clears all and ignores bg_flags)

and these, which can twiddle individual bits in bg_flags:

void ext2fs_bg_flag_set(ext2_filsys fs, dgrp_t group, __u16 bg_flag);
void ext2fs_bg_flag_clear(ext2_filsys fs, dgrp_t group, __u16 bg_flag);

A better interface, after the patch below, is just:

ext2fs_bg_flags_zap(fs, group) /* zeros bg_flags */
ext2fs_bg_flags_set(fs, group, flags) /* adds flags to bg_flags */
ext2fs_bg_flags_clear(fs, group, flags) /* clears flags in bg_flags */

and remove the original ext2fs_bg_flags_set / ext2fs_bg_flags_clear.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-10-25 21:41:32 -04:00
Valerie Aurora Henson 4efbac6fed Convert uses of super->s_*_blocks_count to ext2fs_*_blocks_count()
Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: Nick Dokos <nicholas.dokos@hp.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-07 20:46:34 -04:00
Valerie Aurora Henson a63745e81c Use ext2fs_file_acl_block() instead of using .i_file_acl directly
This provides support for 48-bit file acl blocks.

Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-07 22:29:45 -04:00
Peng Tao 2884d208a3 resize2fs: fix minimum resize size calculation with flex_bg
When flex_bg is on, calculate_minimum_resize_size() should add more meta
blocks for newly added flex_bg.

Addresses-RedHat-Bugzilla: #519131
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2009-09-07 16:21:19 -04:00
Theodore Ts'o 732c8cd58f Use accessor functions fields for bg_flags in the block group descriptors
Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-07 21:15:12 -04:00
Valerie Aurora Henson 24a117abd0 Convert to use io_channel_read_blk64() and io_channel_write_blk64()
Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-07 21:14:24 -04:00
Theodore Ts'o dc615a21c3 Merge branch 'maint' into next 2009-09-07 17:02:35 -04:00
Valerie Aurora Henson 3346084bea resize2fs: Move everything to new bitmap interface
Signed-off-by: Valerie Aurora Henson <vaurora@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-08-22 21:13:37 -04:00
Theodore Ts'o 96cdb37e27 resize2fs: If resize2fs fails, tell the user to run e2fsck
If the resize operation fails in the middle of the operation, mark the
filesystem as needing to be checked, and tell the user that they
should run e2fsck -fy on the device.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-07-11 14:16:39 -04:00
Eric Sandeen 8a6ede8b7a resize2fs: update sb journal backup if journal was moved
This was reported in Fedora, since the livecd creator does
a lot of resizing.

If we've moved the journal blocks during resize (more likely now,
due to the journal being in the middle) the backup blocks in the
superblock don't get updated, and a subsequent e2fsck will find
issues:

e2fsck 1.41.6 (30-May-2009)
Backing up journal inode block information.

Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/mnt/test/img: ***** FILE SYSTEM WAS MODIFIED *****
/mnt/test/img: 11/16000 files (0.0% non-contiguous), 17789/38400 blocks

This can be shown in a simple test:

# dd if=/dev/zero of=img bs=1 count=0 seek=3000M
# mke2fs -t ext4 -F img
# resize2fs img 150M
# e2fsck -f img

(thanks to the Fedora reporter Mads Kiilerich for the testcase!
https://bugzilla.redhat.com/show_bug.cgi?id=506105#c2)

So, update the backup journal in the superblock before resize2fs exits.

Addresses-RedHat-Bugzilla: #505339

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-06-18 07:47:54 -04:00
Theodore Ts'o e2ca097fc6 resize2fs: fix miscellaneous memory leaks
Fix various memory leaks which were discovered using valgrind.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-06-15 03:54:31 -04:00
Eric Sandeen 69f7c80eaf resize2fs: fix minimum size calculations
The extra padding added to the minimum size calculations:

        /*
         * We need to reserve a few extra blocks if extents are
         * enabled, in case we need to grow the extent tree.  The more
         * we shrink the file system, the more space we need.
         */
        if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
                blks_needed += (fs->super->s_blocks_count - blks_needed)/500;

can go quite wrong if we've already added up more "blks_needed"
than our current size, and the above subtraction wraps.  This can
easily happen for a filesystem which is almost completely full.

In this case, just return the current fs size as the minimum and
be done with it.

With this fix we could probably call calculate_minimum_resize_size()
for each resize2fs invocation and refuse to resize smaller than that?

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2009-05-25 22:40:35 -04:00
Theodore Ts'o 2d7361ebfa resize2fs: Fix corruption bug impacting ext4 filesystems with uninit_bg
Due to a fencepost bug, when skipping a block group whose block bitmap
was uninitialized (and hence could not contain any blocks eligible for
relaocation), the block immediately following the block group wasn't
checked as well.  If it was in use and required relocation, it
wouldn't get properly relocated, with the result that an inode using
such a block would end up, post resize, with a pointer to a block now
outside the bounds of the filesystem.

This commit fixes this fencepost error.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-04-18 22:42:13 -04:00
Theodore Ts'o c09043f1ab resize2fs: Fix data corruption bug when shrinking the inode table for ext4
If we need to shrink the inode table, we need to make sure the inodes
contained in the part of the inode table we are vacating don't get
reused as part of the filesystem shrink operation.  This wasn't a
problem with ext3 filesystems, since the inode table was located in
the block group that was going away, so that location was not eligible
for reallocation.

However with ext4 filesystems with flex_bg enabled, it's possible for
a portion of the inode table in the last flex_bg group to be
deallocated, but in a part of the filesystem which could be used as
data blocks.  So we must mark those blocks as reserved to prevent
their reuse, and adjust the minimum filesystem size calculation to
assure that we don't shrink a filesystem too small for the resize
operation to succeed.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-04-18 22:32:03 -04:00