When ext2 mounts a filesystem, it attempts to set the block device
blocksize with a call to sb_set_blocksize, which can fail for
several reasons.  The current failure message in ext2 prints:

  EXT2-fs (loop1): error: blocksize is too small

which is not correct in all cases.  This can be demonstrated
by creating a filesystem with

  # mkfs.ext2 -b 8192

on a 4k page system, and attempting to mount it.

Change the error message to a more generic:

  EXT2-fs (loop1): bad blocksize 8192

to match the error message in ext3.

Signed-off-by: Robin Dong <sanbai@taobao.com>
Reviewed-by: Coly Li <bosong.ly@taobao.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG
  ext3: Remove redundant unlikely()
  ext2: Remove redundant unlikely()
  ext3: speed up file creates by optimizing rec_len functions
  ext2: speed up file creates by optimizing rec_len functions
  ext3: Add more journal error check
  ext3: Add journal error check in resize.c
  quota: Use %pV and __attribute__((format (printf in __quota_error and fix fallout
  ext3: Add FITRIM handling
  ext3: Add batched discard support for ext3
  ext3: Add journal error check into ext3_rename()
  ext3: Use search_dirblock() in ext3_dx_find_entry()
  ext3: Avoid uninitialized memory references with a corrupted htree directory
  ext3: Return error code from generic_check_addressable
  ext3: Add journal error check into ext3_delete_entry()
  ext3: Add error check in ext3_mkdir()
  fs/ext3/super.c: Use printf extension %pV
  fs/ext2/super.c: Use printf extension %pV
  ext3: don't update sb journal_devnum when RO dev

RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

Using %pV reduces the number of printk calls and
eliminates any possible message interleaving from
other printk calls.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jan Kara <jack@suse.cz>

... and switch of the obvious get_sb_bdev() users to ->mount()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It's pointless - we *do* have busy inodes (root directory,
for one), so that call will fail and attempt to change
XIP flag will be ignored.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The BKL is still used in ext2_put_super(), ext2_fill_super(), ext2_sync_fs()
ext2_remount() and ext2_write_inode(). From these calls ext2_put_super(),
ext2_fill_super() and ext2_remount() are protected against each other by
the struct super_block s_umount rw semaphore. The call in ext2_write_inode()
could only protect the modification of the ext2_sb_info through
ext2_update_dynamic_rev() against concurrent ext2_sync_fs() or ext2_remount().
ext2_fill_super() and ext2_put_super() can be left out because you need a
valid filesystem reference in all three cases, which you do not have when
you are one of these functions.

If the BKL is only protecting the modification of the ext2_sb_info it can
safely be removed since this is protected by the struct ext2_sb_info s_lock.

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.

I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.

do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.

Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.

[arnd: do not add the BKL to those file systems that already
       don't use it elsewhere]

Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>