ext4 uses the high bit of the extent length to encode whether the extent
is intialized or not. The helper function ext4_ext_get_actual_len should
be used to get the actual length of the extent.

This addresses the kernel bug documented here: 
     http://bugzilla.kernel.org/show_bug.cgi?id=9732

kernel BUG at fs/ext4/extents.c:1056!
....
Call Trace:
[<ffffffff88366073>] :ext4dev:ext4_ext_get_blocks+0x5ba/0x8c1
[<ffffffff81053c91>] lock_release_holdtime+0x27/0x49
[<ffffffff812748f6>] _spin_unlock+0x17/0x20
[<ffffffff883400a6>] :jbd2:start_this_handle+0x4e0/0x4fe
[<ffffffff88366564>] :ext4dev:ext4_fallocate+0x175/0x39a
[<ffffffff81053c91>] lock_release_holdtime+0x27/0x49
[<ffffffff81056480>] __lock_acquire+0x4e7/0xc4d
[<ffffffff81053c91>] lock_release_holdtime+0x27/0x49
[<ffffffff810a8de7>] sys_fallocate+0xe4/0x10d
[<ffffffff8100c043>] tracesys+0xd5/0xda
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Fix bug reported by Dmitry Monakhov caused by lost error code

    Testcase: 

    blksize = 0x1000;
    fd = open(argv[1], O_RDWR|O_CREAT, 0700);
    unsigned long long sz = 0x10000000UL;
    /* allocating big blocks chunk */
    syscall(__NR_fallocate, fd, 0, 0UL, sz)

    /* grab all other available filesystem space */
    tfd = open("tmp", O_RDWR|O_CREAT|O_DIRECT, 0700);
    while( write(tfd, buf, 4096) > 0); /* loop untill ENOSPC */
    fsync(fd); /* just in case */
    while (pos < sz) {
    	/* each seek+ write operation result in splits uninitialized extent
    	in three extents. Splitting may result in new extent allocation
    	which probably will fail because of ENOSPC*/

    	lseek(fd, blksize*2 -1, SEEK_CUR);
    	if ((ret = write(fd, 'a', 1)) != 1)
    		exit(1);
    	pos += blksize * 2;
    }
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

sb_set_blocksize validates whether the specfied block size can be used by
the file system. Make sure we fail mounting the file system if the
blocksize specfied cannot be used.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

Add stripe= option to /proc/mounts for ext4 filesystems.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

Enable the multiblock allocator by default.

Fix ext4_show_options() so if it is not enabled, the nomballoc option
included in /proc/mounts.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NAlex Tomas <alex@clusterfs.com>
Signed-off-by: NAndreas Dilger <adilger@clusterfs.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Add the functions ext4_ext_search_left() and ext4_ext_search_right(),
which are used by mballoc during ext4_ext_get_blocks to decided whether
to merge extent information.
Signed-off-by: NAlex Tomas <alex@clusterfs.com>
Signed-off-by: NAndreas Dilger <adilger@clusterfs.com>
Signed-off-by: NJohann Lombardi <johann@clusterfs.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Builds with EXT4FS_DEBUG defined (to enable ext4_debug()) fail
without these changes.  Clean up some format warnings too.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

We need to look at the default value and make sure
the mount options are not set via default value
before showing them via ext4_show_options
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

The below patch add ioctl for migrating ext3 indirect block mapped inode
to ext4 extent mapped inode.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

This patch adds 64-bit inode version support to ext4. The lower 32 bits
are stored in the osd1.linux1.l_i_version field while the high 32 bits
are stored in the i_version_hi field newly created in the ext4_inode.
This field is incremented in case the ext4_inode is large enough. A
i_version mount option has been added to enable the feature.
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: NAndreas Dilger <adilger@clusterfs.com>
Signed-off-by: NKalpak Shah <kalpak@clusterfs.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NJean Noel Cordenner <jean-noel.cordenner@bull.net>

The journal checksum feature adds two new flags i.e
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT and JBD2_FEATURE_COMPAT_CHECKSUM.

JBD2_FEATURE_CHECKSUM flag indicates that the commit block contains the
checksum for the blocks described by the descriptor blocks.
Due to checksums, writing of the commit record no longer needs to be
synchronous. Now commit record can be sent to disk without waiting for
descriptor blocks to be written to disk. This behavior is controlled
using JBD2_FEATURE_ASYNC_COMMIT flag. Older kernels/e2fsck should not be
able to recover the journal with _ASYNC_COMMIT hence it is made
incompat.
The commit header has been extended to hold the checksum along with the
type of the checksum.

For recovery in pass scan checksums are verified to ensure the sanity
and completeness(in case of _ASYNC_COMMIT) of every transaction.
Signed-off-by: NAndreas Dilger <adilger@clusterfs.com>
Signed-off-by: NGirish Shilamkar <girish@clusterfs.com>
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

When we are overwriting a file and not actually allocating new file system
blocks we need to take only the read lock on i_data_sem.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

We are currently taking the truncate_mutex for every read. This would have
performance impact on large CPU configuration. Convert the lock to read write
semaphore and take read lock when we are trying to read the file.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

When doing a migrate from ext3 to ext4 inode we need to make sure the test
for inode type and walking inode data happens inside  lock. To make this
happen move truncate_mutex early before checking the i_flags.


This actually should enable us to remove the verify_chain().
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

The unused code found in ext3_find_entry() is also present (and still
unused) in the ext4_find_entry() code. This patch removes it.
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_ext_get_blocks returns negative values on error. We should
check for  <= 0
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

When a new block bitmap is read from disk in read_block_bitmap()
there are a few bits that should ALWAYS be set.  In particular,
the blocks given corresponding to block bitmap, inode bitmap and inode tables.
Validate the block bitmap against these blocks.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

ext4 file system was by default ignoring errors and continuing. This
is not a good default as continuing on error could lead to file system
corruption. Change the default to mark the file system
readonly. Debian and ubuntu already does this as the default in their
fstab.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

When mounting an ext4 filesystem with corrupted s_first_data_block, things
can go very wrong and oops.

Because blocks_count in ext4_fill_super is a u64, and we must use do_div,
the calculation of db_count is done differently than on ext4.  If
first_data_block is corrupted such that it is larger than ext4_blocks_count,
for example, then the intermediate blocks_count value may go negative,
but sign-extend to a very large value:

        blocks_count = (ext4_blocks_count(es) -
                        le32_to_cpu(es->s_first_data_block) +
                        EXT4_BLOCKS_PER_GROUP(sb) - 1);

This is then assigned to s_groups_count which is an unsigned long:

        sbi->s_groups_count = blocks_count;

This may result in a value of 0xFFFFFFFF which is then used to compute
db_count:

        db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
                   EXT4_DESC_PER_BLOCK(sb);

and in this case db_count will wind up as 0 because the addition overflows
32 bits.  This in turn causes the kmalloc for group_desc to be of 0 size:

        sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
                                    GFP_KERNEL);

and eventually in ext4_check_descriptors, dereferencing
sbi->s_group_desc[desc_block] will result in a NULL pointer dereference.

The simplest test seems to be to sanity check s_first_data_block,
EXT4_BLOCKS_PER_GROUP, and ext4_blocks_count values to be sure
their combination won't result in a bad intermediate value for
blocks_count.  We could just check for db_count == 0, but
catching it at the root cause seems like it provides more info.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NMingming Cao <cmm@us.ibm.com>

Based on a report by Robert P. J. Day.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

This fix some instances where we were continuing after calling
ext4_error. ext4_error call panic only if errors=panic mount option is
set. So we need to make sure we return correctly after ext4_error call

Reported by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Calculate & store the max offset for bitmapped files, and
catch too-large seeks, truncates, and writes in ext4, shortening
or rejecting as appropriate.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>

use 2 different maxbytes functions for bitmapped & extent-based
files.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>

This patch converts ext4_inode i_blocks to represent total
blocks occupied by the inode in file system block size.
Earlier the variable used to represent this in 512 byte
block size. This actually limited the total size of the file.

The feature is enabled transparently when we write an inode
whose i_blocks cannot be represnted as 512 byte units in a
48 bit variable.

inode flag  EXT4_HUGE_FILE_FL
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Use the __le16 l_i_reserved1 field of the linux2 struct of ext4_inode
to represet the higher 16 bits for i_blocks. With this change max_file
size becomes (2**48 -1 )* 512 bytes.

We add a RO_COMPAT feature to the super block to indicate that inode
have i_blocks represented as a split 48 bits. Super block with this
feature set cannot be mounted read write on a kernel with CONFIG_LSF
disabled.

Super block flag EXT4_FEATURE_RO_COMPAT_HUGE_FILE
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Rename ext4_inode.i_dir_acl to i_size_high
drop ext4_inode_info.i_dir_acl as it is not used
Rename ext4_inode.i_size to ext4_inode.i_size_lo
Add helper function for accessing the ext4_inode combined i_size.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Rename i_file_acl to i_file_acl_lo. This helps
in finding bugs where we use i_file_acl instead
of the combined i_file_acl_lo and i_file_acl_high
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Fix sparse warnings related to static functions
and local variables.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Introduce ext4_update_*_feature and use them instead
of opencoding.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

This patch fixes various places where the group number is set to a negative
value.
Signed-off-by: NAvantika Mathur <mathur@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In many places variables for block group are of type int, which limits the
maximum number of block groups to 2^31.  Each block group can have up to
2^15 blocks, with a 4K block size,  and the max filesystem size is limited to
2^31 * (2^15 * 2^12) = 2^58  -- or 256 PB

This patch introduces a new type ext4_group_t, of type unsigned long, to
represent block group numbers in ext4.
All occurrences of block group variables are converted to type ext4_group_t.
Signed-off-by: NAvantika Mathur <mathur@us.ibm.com>

There are many casts in extents.c which are not needed,
as the variables are already the type of the cast, or
are being promoted for no particular reason in printk's.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

This patch adds a new data type ext4_lblk_t to represent
the logical file blocks.

This is the preparatory patch to support large files in ext4
The follow up patch with convert the ext4_inode i_blocks to
represent the number of blocks in file system block size. This
changes makes it possible to have a block number 2**32 -1 which
will result in overflow if the block number is represented by
signed long. This patch convert all the block number to type
ext4_lblk_t which is typedef to __u32

Also remove dead code ext4_ext_walk_space
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>

With 64KB blocksize, a directory entry can have size 64KB which does not fit
into 16 bits we have for entry lenght. So we store 0xffff instead and convert
value when read from / written to disk. The patch also converts some places
to use ext4_next_entry() when we are changing them anyway.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

This patch set supports large block size(>4k, <=64k) in ext4,
just enlarging the block size limit. But it is NOT possible to have 64kB
blocksize on ext4 without some changes to the directory handling
code.  The reason is that an empty 64kB directory block would have a
rec_len == (__u16)2^16 == 0, and this would cause an error to be hit in
the filesystem.  The proposed solution is treat 64k rec_len
with a an impossible value like rec_len = 0xffff to handle this.

The Patch-set consists of the following 2 patches.
  [1/2]  ext4: enlarge blocksize
         - Allow blocksize up to pagesize

  [2/2]  ext4: fix rec_len overflow
         - prevent rec_len from overflow with 64KB blocksize

Now on 64k page ppc64 box runs with this patch set we could create a 64k
block size ext4dev, and able to handle empty directory block.
Signed-off-by: NTakashi Sato <sho@tnes.nec.co.jp>
Signed-off-by: NMingming Cao <cmm@us.ibm.com>

As it turns out, the kernel divides by EXT3_INODES_PER_GROUP(s) when
mounting an ext3 filesystem.  If that number is zero, a crash follows.
Below a patch.

This crash was reported by Joeri de Ruiter, Carst Tankink and Pim Vullers.

Cc: <linux-ext4@vger.kernel.org>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Forbid user from changing file flags on quota files.  User has no bussiness
in playing with these flags when quota is on.  Furthermore there is a
remote possibility of deadlock due to a lock inversion between quota file's
i_mutex and transaction's start (i_mutex for quota file is locked only when
trasaction is started in quota operations) in ext3 and ext4.
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: LIOU Payphone <lioupayphone@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Acked-by: NDave Kleikamp <shaggy@austin.ibm.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 7c9e69fa, fixing up
conflicts in fs/ext4/balloc.c manually.

The cost of doing the bitmap validation on each lookup - even when the
bitmap is cached - is absolutely prohibitive.  We could, and probably
should, do it only when adding the bitmap to the buffer cache.  However,
right now we are better off just reverting it.

Peter Zijlstra measured the cost of this extra validation as a 85%
decrease in cached iozone, and while I had a patch that took it down to
just 17% by not being _quite_ so stupid in the validation, it was still
a big slowdown that could have been avoided by just doing it right.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that nfsd has stopped writing to the find_exported_dentry member we an
mark the export_operations const
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>