| Message ID | 20190704181645.16067-1-marcelo.cerri@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [x/azure,c/azure] ext4: fix crash during online resizing | expand |
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Looks good, but BugLink should usually be https://. On 2019-07-04 15:16:45 , Marcelo Henrique Cerri wrote: > From: Jan Kara <jack@suse.cz> > > BugLink: http://bugs.launchpad.net/bugs/1835322 > > When computing maximum size of filesystem possible with given number of > group descriptor blocks, we forget to include s_first_data_block into > the number of blocks. Thus for filesystems with non-zero > s_first_data_block it can happen that computed maximum filesystem size > is actually lower than current filesystem size which confuses the code > and eventually leads to a BUG_ON in ext4_alloc_group_tables() hitting on > flex_gd->count == 0. The problem can be reproduced like: > > truncate -s 100g /tmp/image > mkfs.ext4 -b 1024 -E resize=262144 /tmp/image 32768 > mount -t ext4 -o loop /tmp/image /mnt > resize2fs /dev/loop0 262145 > resize2fs /dev/loop0 300000 > > Fix the problem by properly including s_first_data_block into the > computed number of filesystem blocks. > > Fixes: 1c6bd7173d66 "ext4: convert file system to meta_bg if needed..." > Signed-off-by: Jan Kara <jack@suse.cz> > Signed-off-by: Theodore Ts'o <tytso@mit.edu> > Cc: stable@vger.kernel.org > (cherry picked from commit f96c3ac8dfc24b4e38fc4c2eba5fea2107b929d1) > Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> > --- > fs/ext4/resize.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c > index c38f9e838aef..b7809d16a5d4 100644 > --- a/fs/ext4/resize.c > +++ b/fs/ext4/resize.c > @@ -1957,7 +1957,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) > le16_to_cpu(es->s_reserved_gdt_blocks); > n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); > n_blocks_count = (ext4_fsblk_t)n_group * > - EXT4_BLOCKS_PER_GROUP(sb); > + EXT4_BLOCKS_PER_GROUP(sb) + > + le32_to_cpu(es->s_first_data_block); > n_group--; /* set to last group number */ > } > > -- > 2.20.1 > > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
On 2019-07-04 15:16:45, Marcelo Henrique Cerri wrote: > From: Jan Kara <jack@suse.cz> > > BugLink: http://bugs.launchpad.net/bugs/1835322 > > When computing maximum size of filesystem possible with given number of > group descriptor blocks, we forget to include s_first_data_block into > the number of blocks. Thus for filesystems with non-zero > s_first_data_block it can happen that computed maximum filesystem size > is actually lower than current filesystem size which confuses the code > and eventually leads to a BUG_ON in ext4_alloc_group_tables() hitting on > flex_gd->count == 0. The problem can be reproduced like: > > truncate -s 100g /tmp/image > mkfs.ext4 -b 1024 -E resize=262144 /tmp/image 32768 > mount -t ext4 -o loop /tmp/image /mnt > resize2fs /dev/loop0 262145 > resize2fs /dev/loop0 300000 > > Fix the problem by properly including s_first_data_block into the > computed number of filesystem blocks. > > Fixes: 1c6bd7173d66 "ext4: convert file system to meta_bg if needed..." > Signed-off-by: Jan Kara <jack@suse.cz> > Signed-off-by: Theodore Ts'o <tytso@mit.edu> > Cc: stable@vger.kernel.org > (cherry picked from commit f96c3ac8dfc24b4e38fc4c2eba5fea2107b929d1) > Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> Acked-by: Tyler Hicks <tyhicks@canonical.com> Tyler > --- > fs/ext4/resize.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c > index c38f9e838aef..b7809d16a5d4 100644 > --- a/fs/ext4/resize.c > +++ b/fs/ext4/resize.c > @@ -1957,7 +1957,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) > le16_to_cpu(es->s_reserved_gdt_blocks); > n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); > n_blocks_count = (ext4_fsblk_t)n_group * > - EXT4_BLOCKS_PER_GROUP(sb); > + EXT4_BLOCKS_PER_GROUP(sb) + > + le32_to_cpu(es->s_first_data_block); > n_group--; /* set to last group number */ > } > > -- > 2.20.1 > > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
On Thu, Jul 4, 2019 at 3:16 PM Marcelo Henrique Cerri <marcelo.cerri@canonical.com> wrote: > > From: Jan Kara <jack@suse.cz> > > BugLink: http://bugs.launchpad.net/bugs/1835322 > > When computing maximum size of filesystem possible with given number of > group descriptor blocks, we forget to include s_first_data_block into > the number of blocks. Thus for filesystems with non-zero > s_first_data_block it can happen that computed maximum filesystem size > is actually lower than current filesystem size which confuses the code > and eventually leads to a BUG_ON in ext4_alloc_group_tables() hitting on > flex_gd->count == 0. The problem can be reproduced like: > > truncate -s 100g /tmp/image > mkfs.ext4 -b 1024 -E resize=262144 /tmp/image 32768 > mount -t ext4 -o loop /tmp/image /mnt > resize2fs /dev/loop0 262145 > resize2fs /dev/loop0 300000 > > Fix the problem by properly including s_first_data_block into the > computed number of filesystem blocks. > > Fixes: 1c6bd7173d66 "ext4: convert file system to meta_bg if needed..." > Signed-off-by: Jan Kara <jack@suse.cz> > Signed-off-by: Theodore Ts'o <tytso@mit.edu> > Cc: stable@vger.kernel.org > (cherry picked from commit f96c3ac8dfc24b4e38fc4c2eba5fea2107b929d1) > Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> > --- > fs/ext4/resize.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c > index c38f9e838aef..b7809d16a5d4 100644 > --- a/fs/ext4/resize.c > +++ b/fs/ext4/resize.c > @@ -1957,7 +1957,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) > le16_to_cpu(es->s_reserved_gdt_blocks); > n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); > n_blocks_count = (ext4_fsblk_t)n_group * > - EXT4_BLOCKS_PER_GROUP(sb); > + EXT4_BLOCKS_PER_GROUP(sb) + > + le32_to_cpu(es->s_first_data_block); > n_group--; /* set to last group number */ > } > > -- > 2.20.1 >
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index c38f9e838aef..b7809d16a5d4 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1957,7 +1957,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) le16_to_cpu(es->s_reserved_gdt_blocks); n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); n_blocks_count = (ext4_fsblk_t)n_group * - EXT4_BLOCKS_PER_GROUP(sb); + EXT4_BLOCKS_PER_GROUP(sb) + + le32_to_cpu(es->s_first_data_block); n_group--; /* set to last group number */ }