ext4: fix i_data_sem unlock order in ext4_ind_migrate()

Fuzzing reports a possible deadlock in jbd2_log_wait_commit.

This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require
synchro

ext4: fix i_data_sem unlock order in ext4_ind_migrate()

Fuzzing reports a possible deadlock in jbd2_log_wait_commit.

This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require
synchronous updates because the file descriptor is opened with O_SYNC.
This can lead to the jbd2_journal_stop() function calling
jbd2_might_wait_for_commit(), potentially causing a deadlock if the
EXT4_IOC_MIGRATE call races with a write(2) system call.

This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this
case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the
jbd2_journal_stop function while i_data_sem is locked. This triggers
lockdep because the jbd2_journal_start function might also lock the same
jbd2_handle simultaneously.

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

Reviewed-by: Ritesh Harjani (IBM) <[email protected]>
Co-developed-by: Mikhail Ukhin <[email protected]>
Signed-off-by: Mikhail Ukhin <[email protected]>
Signed-off-by: Artem Sadovnikov <[email protected]>
Rule: add
Link: https://lore.kernel.org/stable/20240404095000.5872-1-mish.uxin2012%40yandex.ru
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

show more ...

ext4: get rid of ppath in ext4_ext_insert_extent()

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

T

ext4: get rid of ppath in ext4_ext_insert_extent()

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

To get rid of the ppath in ext4_ext_insert_extent(), the following is done
here:

* Free the extents path when an error is encountered.
* Its caller needs to update ppath if it uses ppath.
* Free path when npath is used, free npath when it is not used.
* The got_allocated_blocks label in ext4_ext_map_blocks() does not
update err now, so err is updated to 0 if the err returned by
ext4_ext_search_right() is greater than 0 and is about to enter
got_allocated_blocks.

No functional changes.

Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Ojaswin Mujoo <[email protected]>
Tested-by: Ojaswin Mujoo <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: avoid deadlock in fs reclaim with page writeback

Ext4 has a filesystem wide lock protecting ext4_writepages() calls to
avoid races with switching of journalled data flag or inode format. This

ext4: avoid deadlock in fs reclaim with page writeback

Ext4 has a filesystem wide lock protecting ext4_writepages() calls to
avoid races with switching of journalled data flag or inode format. This
lock can however cause a deadlock like:

CPU0 CPU1

ext4_writepages()
percpu_down_read(sbi->s_writepages_rwsem);
ext4_change_inode_journal_flag()
percpu_down_write(sbi->s_writepages_rwsem);
- blocks, all readers block from now on
ext4_do_writepages()
ext4_init_io_end()
kmem_cache_zalloc(io_end_cachep, GFP_KERNEL)
fs_reclaim frees dentry...
dentry_unlink_inode()
iput() - last ref =>
iput_final() - inode dirty =>
write_inode_now()...
ext4_writepages() tries to acquire sbi->s_writepages_rwsem
and blocks forever

Make sure we cannot recurse into filesystem reclaim from writeback code
to avoid the deadlock.

Reported-by: [email protected]
Link: https://lore.kernel.org/all/[email protected]
Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal mode and ext4_writepages")
CC: [email protected]
Signed-off-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: fix warning in 'ext4_da_release_space'

Syzkaller report issue as follows:
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=0
EXT4-fs (loop0): dirty_blocks=0
EXT4-fs (loop

ext4: fix warning in 'ext4_da_release_space'

Syzkaller report issue as follows:
EXT4-fs (loop0): Free/Dirty block details
EXT4-fs (loop0): free_blocks=0
EXT4-fs (loop0): dirty_blocks=0
EXT4-fs (loop0): Block reservation details
EXT4-fs (loop0): i_reserved_data_blocks=0
EXT4-fs warning (device loop0): ext4_da_release_space:1527: ext4_da_release_space: ino 18, to_free 1 with only 0 reserved data blocks
------------[ cut here ]------------
WARNING: CPU: 0 PID: 92 at fs/ext4/inode.c:1528 ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1524
Modules linked in:
CPU: 0 PID: 92 Comm: kworker/u4:4 Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1528
RSP: 0018:ffffc900015f6c90 EFLAGS: 00010296
RAX: 42215896cd52ea00 RBX: 0000000000000000 RCX: 42215896cd52ea00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: 1ffff1100e907d96 R08: ffffffff816aa79d R09: fffff520002bece5
R10: fffff520002bece5 R11: 1ffff920002bece4 R12: ffff888021fd2000
R13: ffff88807483ecb0 R14: 0000000000000001 R15: ffff88807483e740
FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555569ba628 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_es_remove_extent+0x1ab/0x260 fs/ext4/extents_status.c:1461
mpage_release_unused_pages+0x24d/0xef0 fs/ext4/inode.c:1589
ext4_writepages+0x12eb/0x3be0 fs/ext4/inode.c:2852
do_writepages+0x3c3/0x680 mm/page-writeback.c:2469
__writeback_single_inode+0xd1/0x670 fs/fs-writeback.c:1587
writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1870
wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2044
wb_do_writeback fs/fs-writeback.c:2187 [inline]
wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2227
process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>

Above issue may happens as follows:
ext4_da_write_begin
ext4_create_inline_data
ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA);
__ext4_ioctl
ext4_ext_migrate -> will lead to eh->eh_entries not zero, and set extent flag
ext4_da_write_begin
ext4_da_convert_inline_data_to_extent
ext4_da_write_inline_data_begin
ext4_da_map_blocks
ext4_insert_delayed_block
if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk))
if (!ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk))
ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk)); -> will return 1
allocated = true;
ext4_es_insert_delayed_block(inode, lblk, allocated);
ext4_writepages
mpage_map_and_submit_extent(handle, &mpd, &give_up_on_write); -> return -ENOSPC
mpage_release_unused_pages(&mpd, give_up_on_write); -> give_up_on_write == 1
ext4_es_remove_extent
ext4_da_release_space(inode, reserved);
if (unlikely(to_free > ei->i_reserved_data_blocks))
-> to_free == 1 but ei->i_reserved_data_blocks == 0
-> then trigger warning as above

To solve above issue, forbid inode do migrate which has inline data.

Cc: [email protected]
Reported-by: [email protected]
Signed-off-by: Ye Bin <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: factor out ext4_free_ext_path()

Factor out ext4_free_ext_path() to free extent path. As after previous patch
'ext4_ext_drop_refs()' is only used in 'extents.c', so make it static.

Signed-off-

ext4: factor out ext4_free_ext_path()

Factor out ext4_free_ext_path() to free extent path. As after previous patch
'ext4_ext_drop_refs()' is only used in 'extents.c', so make it static.

Signed-off-by: Ye Bin <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: recover csum seed of tmp_inode after migrating to extents

When migrating to extents, the checksum seed of temporary inode
need to be replaced by inode's, otherwise the inode checksums
will be

ext4: recover csum seed of tmp_inode after migrating to extents

When migrating to extents, the checksum seed of temporary inode
need to be replaced by inode's, otherwise the inode checksums
will be incorrect when swapping the inodes data.

However, the temporary inode can not match it's checksum to
itself since it has lost it's own checksum seed.

mkfs.ext4 -F /dev/sdc
mount /dev/sdc /mnt/sdc
xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/sdc/testfile
chattr -e /mnt/sdc/testfile
chattr +e /mnt/sdc/testfile
umount /dev/sdc
fsck -fn /dev/sdc

========
...
Pass 1: Checking inodes, blocks, and sizes
Inode 13 passes checks, but checksum does not match inode. Fix? no
...
========

The fix is simple, save the checksum seed of temporary inode, and
recover it after migrating to extents.

Fixes: e81c9302a6c3 ("ext4: set csum seed in tmp inode while migrating to extents")
Signed-off-by: Li Lingfeng <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: fix a doubled word "need" in a comment

Signed-off-by: Xiang wangx <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'

ext4: fix a doubled word "need" in a comment

Signed-off-by: Xiang wangx <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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fs/ext4: fix comments mentioning i_mutex

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Signed-off-by: hongnanli <[email protected]

fs/ext4: fix comments mentioning i_mutex

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Signed-off-by: hongnanli <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: don't use the orphan list when migrating an inode

We probably want to remove the indirect block to extents migration
feature after a deprecation window, but until then, let's fix a
potential d

ext4: don't use the orphan list when migrating an inode

We probably want to remove the indirect block to extents migration
feature after a deprecation window, but until then, let's fix a
potential data loss problem caused by the fact that we put the
tmp_inode on the orphan list. In the unlikely case where we crash and
do a journal recovery, the data blocks belonging to the inode being
migrated are also represented in the tmp_inode on the orphan list ---
and so its data blocks will get marked unallocated, and available for
reuse.

Instead, stop putting the tmp_inode on the oprhan list. So in the
case where we crash while migrating the inode, we'll leak an inode,
which is not a disaster. It will be easily fixed the next time we run
fsck, and it's better than potentially having blocks getting claimed
by two different files, and losing data as a result.

Signed-off-by: Theodore Ts'o <[email protected]>
Reviewed-by: Lukas Czerner <[email protected]>
Cc: [email protected]

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ext4: set csum seed in tmp inode while migrating to extents

When migrating to extents, the temporary inode will have it's own checksum
seed. This means that, when swapping the inodes data, the inod

ext4: set csum seed in tmp inode while migrating to extents

When migrating to extents, the temporary inode will have it's own checksum
seed. This means that, when swapping the inodes data, the inode checksums
will be incorrect.

This can be fixed by recalculating the extents checksums again. Or simply
by copying the seed into the temporary inode.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=213357
Reported-by: Jeroen van Wolffelaar <[email protected]>
Signed-off-by: Luís Henriques <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]

show more ...

ext4: fix various seppling typos

Signed-off-by: Bhaskar Chowdhury <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <tyt

ext4: fix various seppling typos

Signed-off-by: Bhaskar Chowdhury <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

show more ...

ext4: handle ext4_mark_inode_dirty errors

ext4_mark_inode_dirty() can fail for real reasons. Ignoring its return
value may lead ext4 to ignore real failures that would result in
corruption / crashes

ext4: handle ext4_mark_inode_dirty errors

ext4_mark_inode_dirty() can fail for real reasons. Ignoring its return
value may lead ext4 to ignore real failures that would result in
corruption / crashes. Harden ext4_mark_inode_dirty error paths to fail
as soon as possible and return errors to the caller whenever
appropriate.

One of the possible scnearios when this bug could affected is that
while creating a new inode, its directory entry gets added
successfully but while writing the inode itself mark_inode_dirty
returns error which is ignored. This would result in inconsistency
that the directory entry points to a non-existent inode.

Ran gce-xfstests smoke tests and verified that there were no
regressions.

Signed-off-by: Harshad Shirwadkar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: fix race between writepages and enabling EXT4_EXTENTS_FL

If EXT4_EXTENTS_FL is set on an inode while ext4_writepages() is running
on it, the following warning in ext4_add_complete_io() can be

ext4: fix race between writepages and enabling EXT4_EXTENTS_FL

If EXT4_EXTENTS_FL is set on an inode while ext4_writepages() is running
on it, the following warning in ext4_add_complete_io() can be hit:

WARNING: CPU: 1 PID: 0 at fs/ext4/page-io.c:234 ext4_put_io_end_defer+0xf0/0x120

Here's a minimal reproducer (not 100% reliable) (root isn't required):

while true; do
sync
done &
while true; do
rm -f file
touch file
chattr -e file
echo X >> file
chattr +e file
done

The problem is that in ext4_writepages(), ext4_should_dioread_nolock()
(which only returns true on extent-based files) is checked once to set
the number of reserved journal credits, and also again later to select
the flags for ext4_map_blocks() and copy the reserved journal handle to
ext4_io_end::handle. But if EXT4_EXTENTS_FL is being concurrently set,
the first check can see dioread_nolock disabled while the later one can
see it enabled, causing the reserved handle to unexpectedly be NULL.

Since changing EXT4_EXTENTS_FL is uncommon, and there may be other races
related to doing so as well, fix this by synchronizing changing
EXT4_EXTENTS_FL with ext4_writepages() via the existing
s_writepages_rwsem (previously called s_journal_flag_rwsem).

This was originally reported by syzbot without a reproducer at
https://syzkaller.appspot.com/bug?extid=2202a584a00fffd19fbf,
but now that dioread_nolock is the default I also started seeing this
when running syzkaller locally.

Link: https://lore.kernel.org/r/[email protected]
Reported-by: [email protected]
Fixes: 6b523df4fb5a ("ext4: use transaction reservation for extent conversion in ext4_end_io")
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Cc: [email protected]

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ext4: Reserve revoke credits for freed blocks

So far we have reserved only relatively high fixed amount of revoke
credits for each transaction. We over-reserved by large amount for most
cases but wh

ext4: Reserve revoke credits for freed blocks

So far we have reserved only relatively high fixed amount of revoke
credits for each transaction. We over-reserved by large amount for most
cases but when freeing large directories or files with data journalling,
the fixed amount is not enough. In fact the worst case estimate is
inconveniently large (maximum extent size) for freeing of one extent.

We fix this by doing proper estimate of the amount of blocks that need
to be revoked when removing blocks from the inode due to truncate or
hole punching and otherwise reserve just a small amount of revoke
credits for each transaction to accommodate freeing of xattrs block or
so.

Signed-off-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

show more ...

ext4: Provide function to handle transaction restarts

Provide ext4_journal_ensure_credits_fn() function to ensure transaction
has given amount of credits and call helper function to prepare for
rest

ext4: Provide function to handle transaction restarts

Provide ext4_journal_ensure_credits_fn() function to ensure transaction
has given amount of credits and call helper function to prepare for
restarting a transaction. This allows to remove some boilerplate code
from various places, add proper error handling for the case where
transaction extension or restart fails, and reduces following changes
needed for proper revoke record reservation tracking.

Signed-off-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: clean up indentation issues, remove extraneous tabs

There are several lines that are indented too far, clean these
up by removing the tabs.

Reviewed-by: Jan Kara <[email protected]>
Signed-off-by:

ext4: clean up indentation issues, remove extraneous tabs

There are several lines that are indented too far, clean these
up by removing the tabs.

Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: add ext4_sb_bread() to disambiguate ENOMEM cases

Today, when sb_bread() returns NULL, this can either be because of an
I/O error or because the system failed to allocate the buffer. Since
it'

ext4: add ext4_sb_bread() to disambiguate ENOMEM cases

Today, when sb_bread() returns NULL, this can either be because of an
I/O error or because the system failed to allocate the buffer. Since
it's an old interface, changing would require changing many call
sites.

So instead we create our own ext4_sb_bread(), which also allows us to
set the REQ_META flag.

Also fixed a problem in the xattr code where a NULL return in a
function could also mean that the xattr was not found, which could
lead to the wrong error getting returned to userspace.

Fixes: ac27a0ec112a ("ext4: initial copy of files from ext3")
Cc: [email protected] # 2.6.19
Signed-off-by: Theodore Ts'o <[email protected]>

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ext4: fix up remaining files with SPDX cleanups

A number of ext4 source files were skipped due because their copyright
permission statements didn't match the expected text used by the
automated conv

ext4: fix up remaining files with SPDX cleanups

A number of ext4 source files were skipped due because their copyright
permission statements didn't match the expected text used by the
automated conversion utilities. I've added SPDX tags for the rest.

While looking at some of these files, I've noticed that we have quite
a bit of variation on the licenses that were used --- in particular
some of the Red Hat licenses on the jbd2 files use a GPL2+ license,
and we have some files that have a LGPL-2.1 license (which was quite
surprising).

I've not attempted to do any license changes. Even if it is perfectly
legal to relicense to GPL 2.0-only for consistency's sake, that should
be done with ext4 developer community discussion.

Signed-off-by: Theodore Ts'o <[email protected]>

show more ...

ext4: do not set posix acls on xattr inodes

We don't need acls on xattr inodes because they are not directly
accessible from user mode.

Besides lockdep complains about recursive locking of xattr_se

ext4: do not set posix acls on xattr inodes

We don't need acls on xattr inodes because they are not directly
accessible from user mode.

Besides lockdep complains about recursive locking of xattr_sem as seen
below.

=============================================
[ INFO: possible recursive locking detected ]
4.11.0-rc8+ #402 Not tainted
---------------------------------------------
python/1894 is trying to acquire lock:
(&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270

but task is already holding lock:
(&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&ei->xattr_sem);
lock(&ei->xattr_sem);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by python/1894:
#0: (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50
#1: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0
#2: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0

stack backtrace:
CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x67/0x99
__lock_acquire+0x5f3/0x1830
lock_acquire+0xb5/0x1d0
down_read+0x2f/0x60
ext4_xattr_get+0x66/0x270
ext4_get_acl+0x43/0x1e0
get_acl+0x72/0xf0
posix_acl_create+0x5e/0x170
ext4_init_acl+0x21/0xc0
__ext4_new_inode+0xffd/0x16b0
ext4_xattr_set_entry+0x5ea/0xb70
ext4_xattr_block_set+0x1b5/0x970
ext4_xattr_set_handle+0x351/0x5d0
ext4_xattr_set+0x124/0x180
ext4_xattr_user_set+0x34/0x40
__vfs_setxattr+0x66/0x80
__vfs_setxattr_noperm+0x69/0x1c0
vfs_setxattr+0xa2/0xb0
setxattr+0x129/0x160
path_setxattr+0x87/0xb0
SyS_setxattr+0xf/0x20
entry_SYSCALL_64_fastpath+0x18/0xad

Signed-off-by: Tahsin Erdogan <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>

show more ...

ext4: fix misspellings in comments.

Signed-off-by: Adam Buchbinder <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>

ext4: clean up feature test macros with predicate functions

Create separate predicate functions to test/set/clear feature flags,
thereby replacing the wordy old macros. Furthermore, clean out the
p

ext4: clean up feature test macros with predicate functions

Create separate predicate functions to test/set/clear feature flags,
thereby replacing the wordy old macros. Furthermore, clean out the
places where we open-coded feature tests.

Signed-off-by: Darrick J. Wong <[email protected]>

show more ...

ext4: correctly migrate a file with a hole at the beginning

Currently ext4_ind_migrate() doesn't correctly handle a file which
contains a hole at the beginning of the file. This caused the migratio

ext4: correctly migrate a file with a hole at the beginning

Currently ext4_ind_migrate() doesn't correctly handle a file which
contains a hole at the beginning of the file. This caused the migration
to be done incorrectly, and then if there is a subsequent following
delayed allocation write to the "hole", this would reclaim the same data
blocks again and results in fs corruption.

# assmuing 4k block size ext4, with delalloc enabled
# skip the first block and write to the second block
xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/ext4/testfile

# converting to indirect-mapped file, which would move the data blocks
# to the beginning of the file, but extent status cache still marks
# that region as a hole
chattr -e /mnt/ext4/testfile

# delayed allocation writes to the "hole", reclaim the same data block
# again, results in i_blocks corruption
xfs_io -c "pwrite 0 4k" /mnt/ext4/testfile
umount /mnt/ext4
e2fsck -nf /dev/sda6
...
Inode 53, i_blocks is 16, should be 8. Fix? no
...

Signed-off-by: Eryu Guan <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]

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ext4: be more strict when migrating to non-extent based file

Currently the check in ext4_ind_migrate() is not enough before doing the
real conversion:

a) delayed allocated extents could bypass the

ext4: be more strict when migrating to non-extent based file

Currently the check in ext4_ind_migrate() is not enough before doing the
real conversion:

a) delayed allocated extents could bypass the check on eh->eh_entries
and eh->eh_depth

This can be demonstrated by this script

xfs_io -fc "pwrite 0 4k" -c "pwrite 8k 4k" /mnt/ext4/testfile
chattr -e /mnt/ext4/testfile

where testfile has two extents but still be converted to non-extent
based file format.

b) only extent length is checked but not the offset, which would result
in data lose (delalloc) or fs corruption (nodelalloc), because
non-extent based file only supports at most (12 + 2^10 + 2^20 + 2^30)
blocks

This can be demostrated by

xfs_io -fc "pwrite 5T 4k" /mnt/ext4/testfile
chattr -e /mnt/ext4/testfile
sync

If delalloc is enabled, dmesg prints
EXT4-fs warning (device dm-4): ext4_block_to_path:105: block 1342177280 > max in inode 53
EXT4-fs (dm-4): Delayed block allocation failed for inode 53 at logical offset 1342177280 with max blocks 1 with error 5
EXT4-fs (dm-4): This should not happen!! Data will be lost

If delalloc is disabled, e2fsck -nf shows corruption
Inode 53, i_size is 5497558142976, should be 4096. Fix? no

Fix the two issues by

a) forcing all delayed allocation blocks to be allocated before checking
eh->eh_depth and eh->eh_entries
b) limiting the last logical block of the extent is within direct map

Signed-off-by: Eryu Guan <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]

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VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <[email protected]>
Signed-off-by:

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Al Viro <[email protected]>

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ext4: update comments regarding ext4_delete_inode()

ext4_delete_inode() has been renamed for a long time, update
comments for this.

Signed-off-by: Wang Shilong <[email protected]>
Signed-off-by: The

ext4: update comments regarding ext4_delete_inode()

ext4_delete_inode() has been renamed for a long time, update
comments for this.

Signed-off-by: Wang Shilong <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>

show more ...