ext2: fix race between setxattr and write back

There's an issue when allocating xattrs as follows:
Block Allocation Reservation Windows Map (ext2_try_to_allocate_with_rsv):
reservation window 0x0000

ext2: fix race between setxattr and write back

There's an issue when allocating xattrs as follows:
Block Allocation Reservation Windows Map (ext2_try_to_allocate_with_rsv):
reservation window 0x000000006f105382 start: 0, end: 0
reservation window 0x000000008fd1a555 start: 1044, end: 1059
Window map complete.
kernel BUG at fs/ext2/balloc.c:1158!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:ext2_try_to_allocate_with_rsv.isra.0+0x15c4/0x1800
Call Trace:
<TASK>
ext2_new_blocks+0x935/0x1690
ext2_new_block+0x73/0xa0
ext2_xattr_set2+0x74f/0x1730
ext2_xattr_set+0x12b6/0x2260
ext2_xattr_user_set+0x9c/0x110
__vfs_setxattr+0x139/0x1d0
__vfs_setxattr_noperm+0xfc/0x370
__vfs_setxattr_locked+0x205/0x2c0
vfs_setxattr+0x19d/0x3b0
do_setxattr+0xff/0x220
setxattr+0x123/0x150
path_setxattr+0x193/0x1e0
__x64_sys_setxattr+0xc8/0x170
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Above issue may happens as follows:
setxattr write back
ext2_xattr_set
ext2_xattr_set2
ext2_new_block
ext2_new_blocks
ext2_try_to_allocate_with_rsv
alloc_new_reservation
--> group=0 [0, 1023] rsv [1016, 1023]
do_writepages
mpage_writepages
write_cache_pages
__mpage_writepage
ext2_get_block
ext2_get_blocks
ext2_alloc_branch
ext2_new_blocks
ext2_try_to_allocate_with_rsv
alloc_new_reservation
-->group=1 [1024, 2047] rsv [1044, 1059]
if ((my_rsv->rsv_start > group_last_block) ||
(my_rsv->rsv_end < group_first_block)
rsv_window_dump
BUG();

Now ext2 mkwrite doesn't allocate new blocks so for these cases we may
be allocating blocks during writeback. However, there is no protection
between ext2_xattr_set() and do_writepages() so these two functions can
conflict on handling the reservation window. To solve about issue don't
use the reservation window when allocating block for xattr.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Message-Id: <20230815112612.221145-4-yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: introduce new flags argument for ext2_new_blocks()

This patch introduces a new flags argument for ext2_new_blocks() and also
a new EXT2_ALLOC_NORESERVE flag.

Signed-off-by: Ye Bin <yebin10@hu

ext2: introduce new flags argument for ext2_new_blocks()

This patch introduces a new flags argument for ext2_new_blocks() and also
a new EXT2_ALLOC_NORESERVE flag.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Message-Id: <20230815112612.221145-3-yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: remove ext2_new_block()

Now, only xattr allocate block use ext2_new_block(), so just opencode it in
the xattr code.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Message-Id: <20230815112612.2211

ext2: remove ext2_new_block()

Now, only xattr allocate block use ext2_new_block(), so just opencode it in
the xattr code.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Message-Id: <20230815112612.221145-2-yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: fix datatype of block number in ext2_xattr_set2()

I run a small server that uses external hard drives for backups. The
backup software I use uses ext2 filesystems with 4KiB block size and
the

ext2: fix datatype of block number in ext2_xattr_set2()

I run a small server that uses external hard drives for backups. The
backup software I use uses ext2 filesystems with 4KiB block size and
the server is running SELinux and therefore relies on xattr. I recently
upgraded the hard drives from 4TB to 12TB models. I noticed that after
transferring some TBs I got a filesystem error "Freeing blocks not in
datazone - block = 18446744071529317386, count = 1" and the backup
process stopped. Trying to fix the fs with e2fsck resulted in a
completely corrupted fs. The error probably came from ext2_free_blocks(),
and because of the large number 18e19 this problem immediately looked
like some kind of integer overflow. Whereas the 4TB fs was about 1e9
blocks, the new 12TB is about 3e9 blocks. So, searching the ext2 code,
I came across the line in fs/ext2/xattr.c:745 where ext2_new_block()
is called and the resulting block number is stored in the variable block
as an int datatype. If a block with a block number greater than
INT32_MAX is returned, this variable overflows and the call to
sb_getblk() at line fs/ext2/xattr.c:750 fails, then the call to
ext2_free_blocks() produces the error.

Signed-off-by: Georg Ottinger <g.ottinger@gmx.at>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230815100340.22121-1-g.ottinger@gmx.at>

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ext2: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

ext2: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-39-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

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ext2: remove redundant assignment to pointer end

Pointer is assigned a value that is never read, the assignment is
redundant and can be removed.

Cleans up clang-scan warning:
fs/ext2/xattr.c:555:3:

ext2: remove redundant assignment to pointer end

Pointer is assigned a value that is never read, the assignment is
redundant and can be removed.

Cleans up clang-scan warning:
fs/ext2/xattr.c:555:3: warning: Value stored to 'end' is never read [deadcode.DeadStores]
end = (char *)header + sb->s_blocksize;

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230317143420.419005-1-colin.i.king@gmail.com>

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fs: rename generic posix acl handlers

Reflect in their naming and document that they are kept around for
legacy reasons and shouldn't be used anymore by new code.

Reviewed-by: Christoph Hellwig <hc

fs: rename generic posix acl handlers

Reflect in their naming and document that they are kept around for
legacy reasons and shouldn't be used anymore by new code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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fs: simplify ->listxattr() implementation

The ext{2,4}, erofs, f2fs, and jffs2 filesystems use the same logic to
check whether a given xattr can be listed. Simplify them and avoid
open-coding the sa

fs: simplify ->listxattr() implementation

The ext{2,4}, erofs, f2fs, and jffs2 filesystems use the same logic to
check whether a given xattr can be listed. Simplify them and avoid
open-coding the same check by calling the helper we introduced earlier.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-erofs@lists.ozlabs.org
Cc: linux-ext4@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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fs: drop unused posix acl handlers

Remove struct posix_acl_{access,default}_handler for all filesystems
that don't depend on the xattr handler in their inode->i_op->listxattr()
method in any way. Th

fs: drop unused posix acl handlers

Remove struct posix_acl_{access,default}_handler for all filesystems
that don't depend on the xattr handler in their inode->i_op->listxattr()
method in any way. There's nothing more to do than to simply remove the
handler. It's been effectively unused ever since we introduced the new
posix acl api.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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ext2: avoid deleting xattr block that is being reused

Currently when we decide to reuse xattr block we detect the case when
the last reference to xattr block is being dropped at the same time and
ca

ext2: avoid deleting xattr block that is being reused

Currently when we decide to reuse xattr block we detect the case when
the last reference to xattr block is being dropped at the same time and
cancel the reuse attempt. Convert ext2 to a new scheme when as soon as
matching mbcache entry is found, we wait with dropping the last xattr
block reference until mbcache entry reference is dropped (meaning either
the xattr block reference is increased or we decided not to reuse the
block).

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-8-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext2: unindent codeblock in ext2_xattr_set()

Replace one else in ext2_xattr_set() with a goto. This makes following
code changes simpler to follow. No functional changes.

Signed-off-by: Jan Kara <j

ext2: unindent codeblock in ext2_xattr_set()

Replace one else in ext2_xattr_set() with a goto. This makes following
code changes simpler to follow. No functional changes.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220712105436.32204-7-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext2: factor our freeing of xattr block reference

Free of xattr block reference is opencode in two places. Factor it out
into a separate function and use it.

Signed-off-by: Jan Kara <jack@suse.cz>

ext2: factor our freeing of xattr block reference

Free of xattr block reference is opencode in two places. Factor it out
into a separate function and use it.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-6-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext2: initialize quota info in ext2_xattr_set()

In order to correctly account/limit space usage, should initialize
quota info before calling quota related functions.

Link: https://lore.kernel.org/r

ext2: initialize quota info in ext2_xattr_set()

In order to correctly account/limit space usage, should initialize
quota info before calling quota related functions.

Link: https://lore.kernel.org/r/20200626054959.114177-1-cgxu519@mykernel.net
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: fix improper assignment for e_value_offs

In the process of changing value for existing EA,
there is an improper assignment of e_value_offs(setting to 0),
because it will be reset to incorrect

ext2: fix improper assignment for e_value_offs

In the process of changing value for existing EA,
there is an improper assignment of e_value_offs(setting to 0),
because it will be reset to incorrect value in the following
loop(shifting EA values before target). Delayed assignment
can avoid this issue.

Link: https://lore.kernel.org/r/20200603084429.25344-1-cgxu519@mykernel.net
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: fix empty body warnings when -Wextra is used

When EXT2_ATTR_DEBUG is not defined, modify the 2 debug macros
to use the no_printk() macro instead of <nothing>.
This fixes gcc warnings when -Wex

ext2: fix empty body warnings when -Wextra is used

When EXT2_ATTR_DEBUG is not defined, modify the 2 debug macros
to use the no_printk() macro instead of <nothing>.
This fixes gcc warnings when -Wextra is used:

../fs/ext2/xattr.c:252:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:258:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:330:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:872:45: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]

I have verified that the only object code change (with gcc 7.5.0) is
the reversal of some instructions from 'cmp a,b' to 'cmp b,a'.

Link: https://lore.kernel.org/r/e18a7395-61fb-2093-18e8-ed4f8cf56248@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jan Kara <jack@suse.com>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: fix debug reference to ext2_xattr_cache

Fix a debug-only build error in ext2/xattr.c:

When building without extra debugging, (and with another patch that uses
no_printk() instead of <empty> f

ext2: fix debug reference to ext2_xattr_cache

Fix a debug-only build error in ext2/xattr.c:

When building without extra debugging, (and with another patch that uses
no_printk() instead of <empty> for the ext2-xattr debug-print macros,
this build error happens:

../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’:
../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in
this function); did you mean ‘ext2_xattr_list’?
atomic_read(&ext2_xattr_cache->c_entry_count));

Fix the problem by removing cached entry count from the debug message
since otherwise we'd have to export the mbcache structure just for that.

Fixes: be0726d33cb8 ("ext2: convert to mbcache2")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: Silence lockdep warning about reclaim under xattr_sem

Lockdep complains about a chain:
sb_internal#2 --> &ei->xattr_sem#2 --> fs_reclaim

and shrink_dentry_list -> ext2_evict_inode -> ext2_x

ext2: Silence lockdep warning about reclaim under xattr_sem

Lockdep complains about a chain:
sb_internal#2 --> &ei->xattr_sem#2 --> fs_reclaim

and shrink_dentry_list -> ext2_evict_inode -> ext2_xattr_delete_inode ->
down_write(ei->xattr_sem) creating a locking cycle in the reclaim path.
This is however a false positive because when we are in
ext2_evict_inode() we are the only holder of the inode reference and
nobody else should touch xattr_sem of that inode. So we cannot ever
block on acquiring the xattr_sem in the reclaim path.

Silence the lockdep warning by using down_write_trylock() in
ext2_xattr_delete_inode() to not create false locking dependency.

Reported-by: "J. R. Okajima" <hooanon05g@gmail.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: fix block range in ext2_data_block_valid()

For block validity we should check the block range
from start_block to start_block + count - 1, so fix
the range in ext2_data_block_valid() and also

ext2: fix block range in ext2_data_block_valid()

For block validity we should check the block range
from start_block to start_block + count - 1, so fix
the range in ext2_data_block_valid() and also modify
the count argument properly in calling place.

Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Link: https://lore.kernel.org/r/20190723112155.20329-1-cgxu519@zoho.com.cn
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: Use kmemdup rather than duplicating its implementation

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memset, which the programmer needs to

ext2: Use kmemdup rather than duplicating its implementation

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memset, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memset.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Link: https://lore.kernel.org/r/20190703131727.25735-1-huangfq.daxian@gmail.com
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: optimize ext2_xattr_get()

Since xattr entry names are sorted, we don't have
to continue when current entry name is greater than
target.

Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Sign

ext2: optimize ext2_xattr_get()

Since xattr entry names are sorted, we don't have
to continue when current entry name is greater than
target.

Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: introduce new helper for xattr entry comparison

Introduce new helper ext2_xattr_cmp_entry() for xattr
entry comparison.

Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan K

ext2: introduce new helper for xattr entry comparison

Introduce new helper ext2_xattr_cmp_entry() for xattr
entry comparison.

Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: merge xattr next entry check to ext2_xattr_entry_valid()

We have introduced ext2_xattr_entry_valid() for xattr
entry sanity check, so it's better to do relevant things
in one place.

Signed-of

ext2: merge xattr next entry check to ext2_xattr_entry_valid()

We have introduced ext2_xattr_entry_valid() for xattr
entry sanity check, so it's better to do relevant things
in one place.

Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: Strengthen xattr block checks

Check every entry in xattr block for validity in ext2_xattr_set() to
detect on disk corruption early. Also since e_value_block field in xattr
entry is never != 0

ext2: Strengthen xattr block checks

Check every entry in xattr block for validity in ext2_xattr_set() to
detect on disk corruption early. Also since e_value_block field in xattr
entry is never != 0 in a valid filesystem, just remove checks for it
once we have established entries are valid.

Reviewed-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: Merge loops in ext2_xattr_set()

There are two very similar loops when searching xattr to set. Just merge
them.

Reviewed-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@s

ext2: Merge loops in ext2_xattr_set()

There are two very similar loops when searching xattr to set. Just merge
them.

Reviewed-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

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ext2: introduce helper for xattr entry validation

Introduce helper function ext2_xattr_entry_valid()
for xattr entry validation and clean up the entry
check related code.

Reviewed-by: Andreas Dilge

ext2: introduce helper for xattr entry validation

Introduce helper function ext2_xattr_entry_valid()
for xattr entry validation and clean up the entry
check related code.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

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