Null-terminating the fscrypt_symlink_data on read is unnecessary because
it is not string data --- it contains binary ciphertext.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Some applications may create multimeida file with temporary name like
'*.jpg.tmp' or '*.mp4.tmp', then rename to '*.jpg' or '*.mp4'.
Now, f2fs can only detect multimedia filename with specified format:
"filename + '.' + extension", so it will make f2fs missing to detect
multimedia file with special temporary name, result in failing to set
cold flag on file.
This patch enhances detection flow for enabling lookup extension in the
middle of temporary filename.
Reported-by: Xue Liu <liuxueliu.liu@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes to report the right error number of f2fs_find_entry to
its caller.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Now we can report an error to f2fs_lookup given by f2fs_find_entry.
Suggested-by: He YunLei <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If we get ENOMEM or EIO in f2fs_find_entry, we should stop right away.
Otherwise, for example, we can get duplicate directory entry by ->chash and
->clevel.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch reduces to call them across the whole tree.
- sync_inode_page()
- update_inode_page()
- update_inode()
- f2fs_write_inode()
Instead, checkpoint will flush all the dirty inode metadata before syncing
node pages.
Note that, this is doable, since we call mark_inode_dirty_sync() for all
inode's field change which needs to update on-disk inode as well.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch calls mark_inode_dirty_sync() for the following on-disk inode
changes.
-> largest
-> ctime/mtime/atime
-> i_current_depth
-> i_xattr_nid
-> i_pino
-> i_advise
-> i_flags
-> i_mode
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces f2fs_i_links_write() to call mark_inode_dirty_sync() when
changing inode->i_links.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Pull f2fs fixes from Jaegeuk Kim.
* tag 'f2fs-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
f2fs: retrieve IO write stat from the right place
f2fs crypto: fix corrupted symlink in encrypted case
f2fs: cover large section in sanity check of super
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the encrypted symlink case, we should check its corrupted symname after
decrypting it.
Otherwise, we can report -ENOENT incorrectly, if encrypted symname starts with
'\0'.
Cc: stable 4.5+ <stable@vger.kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
During ->lookup, I_NEW state of inode was been cleared in f2fs_iget,
so in error path, we don't need to clear it again.
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds the renamed functions moved from the f2fs crypto files.
1. definitions for per-file encryption used by ext4 and f2fs.
2. crypto.c for encrypt/decrypt functions
a. IO preparation:
- fscrypt_get_ctx / fscrypt_release_ctx
b. before IOs:
- fscrypt_encrypt_page
- fscrypt_decrypt_page
- fscrypt_zeroout_range
c. after IOs:
- fscrypt_decrypt_bio_pages
- fscrypt_pullback_bio_page
- fscrypt_restore_control_page
3. policy.c supporting context management.
a. For ioctls:
- fscrypt_process_policy
- fscrypt_get_policy
b. For context permission
- fscrypt_has_permitted_context
- fscrypt_inherit_context
4. keyinfo.c to handle permissions
- fscrypt_get_encryption_info
- fscrypt_free_encryption_info
5. fname.c to support filename encryption
a. general wrapper functions
- fscrypt_fname_disk_to_usr
- fscrypt_fname_usr_to_disk
- fscrypt_setup_filename
- fscrypt_free_filename
b. specific filename handling functions
- fscrypt_fname_alloc_buffer
- fscrypt_fname_free_buffer
6. Makefile and Kconfig
Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If f2fs was corrupted with missing dot dentries in root dirctory,
it needs to recover them after fsck.f2fs set F2FS_INLINE_DOTS flag
in directory inode when fsck.f2fs detects missing dot dentries.
Signed-off-by: Xue Liu <liuxueliu.liu@huawei.com>
Signed-off-by: Yong Sheng <shengyong1@huawei.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When doing test with fstests/generic/068 in inline_dentry enabled f2fs,
following oops dmesg will be reported:
------------[ cut here ]------------
WARNING: CPU: 5 PID: 11841 at fs/inode.c:273 drop_nlink+0x49/0x50()
Modules linked in: f2fs(O) ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state
CPU: 5 PID: 11841 Comm: fsstress Tainted: G O 4.5.0-rc1 #45
Hardware name: Hewlett-Packard HP Z220 CMT Workstation/1790, BIOS K51 v01.61 05/16/2013
0000000000000111 ffff88009cdf7ae8 ffffffff813e5944 0000000000002e41
0000000000000000 0000000000000111 0000000000000000 ffff88009cdf7b28
ffffffff8106a587 ffff88009cdf7b58 ffff8804078fe180 ffff880374a64e00
Call Trace:
[<ffffffff813e5944>] dump_stack+0x48/0x64
[<ffffffff8106a587>] warn_slowpath_common+0x97/0xe0
[<ffffffff8106a5ea>] warn_slowpath_null+0x1a/0x20
[<ffffffff81231039>] drop_nlink+0x49/0x50
[<ffffffffa07b95b4>] f2fs_rename2+0xe04/0x10c0 [f2fs]
[<ffffffff81231ff1>] ? lock_two_nondirectories+0x81/0x90
[<ffffffff813f454d>] ? lockref_get+0x1d/0x30
[<ffffffff81220f70>] vfs_rename+0x2e0/0x640
[<ffffffff8121f9db>] ? lookup_dcache+0x3b/0xd0
[<ffffffff810b8e41>] ? update_fast_ctr+0x21/0x40
[<ffffffff8134ff12>] ? security_path_rename+0xa2/0xd0
[<ffffffff81224af6>] SYSC_renameat2+0x4b6/0x540
[<ffffffff810ba8ed>] ? trace_hardirqs_off+0xd/0x10
[<ffffffff810022ba>] ? exit_to_usermode_loop+0x7a/0xd0
[<ffffffff817e0ade>] ? int_ret_from_sys_call+0x52/0x9f
[<ffffffff810bdc90>] ? trace_hardirqs_on_caller+0x100/0x1c0
[<ffffffff81224b8e>] SyS_renameat2+0xe/0x10
[<ffffffff8121f08e>] SyS_rename+0x1e/0x20
[<ffffffff817e0957>] entry_SYSCALL_64_fastpath+0x12/0x6f
---[ end trace 2b31e17995404e42 ]---
This is because: in the same inline directory, when we renaming one file
from source name to target name which is not existed, once space of inline
dentry is not enough, inline conversion will be triggered, after that all
data in inline dentry will be moved to normal dentry page.
After attaching the new entry in coverted dentry page, still we try to
remove old entry in original inline dentry, since old entry has been
moved, so it obviously doesn't make any effect, result in remaining old
entry in converted dentry page.
Now, we have two valid dentries pointed to the same inode which has nlink
value of 1, deleting them both, above warning appears.
This issue can be reproduced easily as below steps:
1. mount f2fs with inline_dentry option
2. mkdir dir
3. touch 180 files named [001-180] in dir
4. rename dir/180 dir/181
5. rm dir/180 dir/181
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Should check and show correct return value of update_dent_inode in
->rename.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adopts f2fs with codes of ext4, it removes unneeded memory
allocation in creating/accessing path of symlink.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Pull f2fs updates from Jaegeuk Kim:
"This series adds two ioctls to control cached data and fragmented
files. Most of the rest fixes missing error cases and bugs that we
have not covered so far. Summary:
Enhancements:
- support an ioctl to execute online file defragmentation
- support an ioctl to flush cached data
- speed up shrinking of extent_cache entries
- handle broken superblock
- refector dirty inode management infra
- revisit f2fs_map_blocks to handle more cases
- reduce global lock coverage
- add detecting user's idle time
Major bug fixes:
- fix data race condition on cached nat entries
- fix error cases of volatile and atomic writes"
* tag 'for-f2fs-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (87 commits)
f2fs: should unset atomic flag after successful commit
f2fs: fix wrong memory condition check
f2fs: monitor the number of background checkpoint
f2fs: detect idle time depending on user behavior
f2fs: introduce time and interval facility
f2fs: skip releasing nodes in chindless extent tree
f2fs: use atomic type for node count in extent tree
f2fs: recognize encrypted data in f2fs_fiemap
f2fs: clean up f2fs_balance_fs
f2fs: remove redundant calls
f2fs: avoid unnecessary f2fs_balance_fs calls
f2fs: check the page status filled from disk
f2fs: introduce __get_node_page to reuse common code
f2fs: check node id earily when readaheading node page
f2fs: read isize while holding i_mutex in fiemap
Revert "f2fs: check the node block address of newly allocated nid"
f2fs: cover more area with nat_tree_lock
f2fs: introduce max_file_blocks in sbi
f2fs crypto: check CONFIG_F2FS_FS_XATTR for encrypted symlink
f2fs: introduce zombie list for fast shrinking extent trees
...
Add missed CONFIG_F2FS_FS_XATTR for encrypted symlink inode in order
to avoid unneeded registry of ->{get,set,remove}xattr.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If filesystem is readonly, leave user message info instead of recovering
inline dot inode.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
__recover_do_dentries will try to grab free space in storage, so fix to
add missing f2fs_balance_fs here.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If inline_data option is disable, when truncating an inline inode with
size which is not exceed maxinum inline size, we should not convert
inline inode to regular one to avoid the overhead of synchronizing
conversion.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The f2fs_balance_fs doesn't need to cover f2fs_new_inode or f2fs_find_entry
works.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
new method: ->get_link(); replacement of ->follow_link(). The differences
are:
* inode and dentry are passed separately
* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.
It's a flagday change - the old method is gone, all in-tree instances
converted. Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode. That'll change
in the next commits.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new_valid_dev() always returns 1, so the !new_valid_dev() check is not
needed. Remove it.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Changman Lee <cm224.lee@samsung.com>
Cc: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, in ->symlink of f2fs, we kept the fixed invoking order between
f2fs_add_link and page_symlink since we should init node info firstly
in f2fs_add_link, then such node info can be used in page_symlink.
But we didn't fix to release meta info which was done before page_symlink
in our error path, so this will leave us corrupt symlink entry in its
parent's dentry page. Fix this issue by adding f2fs_unlink in the error
path for removing such linking.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We got dentry pages from high_mem, and its address space directly goes into the
decryption path via f2fs_fname_disk_to_usr.
But, sg_init_one assumes the address is not from high_mem, so we can get this
panic since it doesn't call kmap_high but kunmap_high is triggered at the end.
kernel BUG at ../../../../../../kernel/mm/highmem.c:290!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
...
(kunmap_high+0xb0/0xb8) from [<c0114534>] (__kunmap_atomic+0xa0/0xa4)
(__kunmap_atomic+0xa0/0xa4) from [<c035f028>] (blkcipher_walk_done+0x128/0x1ec)
(blkcipher_walk_done+0x128/0x1ec) from [<c0366c24>] (crypto_cbc_decrypt+0xc0/0x170)
(crypto_cbc_decrypt+0xc0/0x170) from [<c0367148>] (crypto_cts_decrypt+0xc0/0x114)
(crypto_cts_decrypt+0xc0/0x114) from [<c035ea98>] (async_decrypt+0x40/0x48)
(async_decrypt+0x40/0x48) from [<c032ca34>] (f2fs_fname_disk_to_usr+0x124/0x304)
(f2fs_fname_disk_to_usr+0x124/0x304) from [<c03056fc>] (f2fs_fill_dentries+0xac/0x188)
(f2fs_fill_dentries+0xac/0x188) from [<c03059c8>] (f2fs_readdir+0x1f0/0x300)
(f2fs_readdir+0x1f0/0x300) from [<c0218054>] (vfs_readdir+0x90/0xb4)
(vfs_readdir+0x90/0xb4) from [<c0218418>] (SyS_getdents64+0x64/0xcc)
(SyS_getdents64+0x64/0xcc) from [<c0105ba0>] (ret_fast_syscall+0x0/0x30)
Cc: <stable@vger.kernel.org>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We should not call unlock_new_inode when insert_inode_locked failed.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds to stat the number of inline xattr inode for
showing in debugfs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When testing with fs_mark, some blocks were written out as cold
data which were mixed with warm data, resulting in splitting more
bios.
This is because fs_mark will create file with random filename as
below:
559551ee~~~~~~~~15Z29OCC05JCKQP60JQ42MKV
559551ee~~~~~~~~NZAZ6X8OA8LHIIP6XD0L58RM
559551ef~~~~~~~~B15YDSWAK789HPSDZKYTW6WM
559551f1~~~~~~~~2DAE5DPS79785BUNTFWBEMP3
559551f1~~~~~~~~1MYDY0BKSQCJPI32Q8C514RM
559551f1~~~~~~~~YQOTMAOMN5CVRFOUNI026MP4
559551f3~~~~~~~~1WF42LPRTQJNPPGR3EINKMPE
559551f3~~~~~~~~8Y2NRK7CEPPAA02LY936PJPG
They are regarded as cold file since their filename are ended with
multimedia files' extension, but this should be wrong as we only
match the extension of filename, not the whole one.
In this patch, we try to fix the format of multimedia filename to:
"filename + '.' + extension", then we set cold file only its
filename matches the format.
So after this change, it will reduce the probability we set the
wrong cold file, also it helps a little for fs_mark's performance
on f2fs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We don't need to handle the duplicate extent information.
The integrated rule is:
- update on-disk extent with largest one tracked by in-memory extent_cache
- destroy extent_tree for the truncation case
- drop per-inode extent_cache by shrinker
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Before iput is called, the inode number used by a bad inode can be reassigned
to other new inode, resulting in any abnormal behaviors on the new inode.
This should not happen for the new inode.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Pull f2fs updates from Jaegeuk Kim:
"New features:
- per-file encryption (e.g., ext4)
- FALLOC_FL_ZERO_RANGE
- FALLOC_FL_COLLAPSE_RANGE
- RENAME_WHITEOUT
Major enhancement/fixes:
- recovery broken superblocks
- enhance f2fs_trim_fs with a discard_map
- fix a race condition on dentry block allocation
- fix a deadlock during summary operation
- fix a missing fiemap result
.. and many minor bug fixes and clean-ups were done"
* tag 'for-f2fs-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (83 commits)
f2fs: do not trim preallocated blocks when truncating after i_size
f2fs crypto: add alloc_bounce_page
f2fs crypto: fix to handle errors likewise ext4
f2fs: drop the volatile_write flag only
f2fs: skip committing valid superblock
f2fs: setting discard option in parse_options()
f2fs: fix to return exact trimmed size
f2fs: support FALLOC_FL_INSERT_RANGE
f2fs: hide common code in f2fs_replace_block
f2fs: disable the discard option when device doesn't support
f2fs crypto: remove alloc_page for bounce_page
f2fs: fix a deadlock for summary page lock vs. sentry_lock
f2fs crypto: clean up error handling in f2fs_fname_setup_filename
f2fs crypto: avoid f2fs_inherit_context for symlink
f2fs crypto: do not set encryption policy for non-directory by ioctl
f2fs crypto: allow setting encryption policy once
f2fs crypto: check context consistent for rename2
f2fs: avoid duplicated code by reusing f2fs_read_end_io
f2fs crypto: use per-inode tfm structure
f2fs: recovering broken superblock during mount
...
This patch fixes to call f2fs_inherit_context twice for newly created symlink.
The original one is called by f2fs_add_link(), which invokes f2fs_setxattr.
If the second one is called again, f2fs_setxattr is triggered again with same
encryption index.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For exchange rename, we should check context consistent of encryption
between new_dir and old_inode or old_dir and new_inode. Otherwise
inheritance of parent's encryption context will be broken.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: sync with ext4 approach]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch applies the following ext4 patch:
ext4 crypto: use per-inode tfm structure
As suggested by Herbert Xu, we shouldn't allocate a new tfm each time
we read or write a page. Instead we can use a single tfm hanging off
the inode's crypt_info structure for all of our encryption needs for
that inode, since the tfm can be used by multiple crypto requests in
parallel.
Also use cmpxchg() to avoid races that could result in crypt_info
structure getting doubly allocated or doubly freed.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
As the description of rename in manual, RENAME_WHITEOUT is a special operation
that only makes sense for overlay/union type filesystem.
When performing rename with RENAME_WHITEOUT, dst will be replace with src, and
meanwhile, a 'whiteout' will be create with name of src.
A "whiteout" is designed to be a char device with 0,0 device number, it has
specially meaning for stackable filesystem. In these filesystems, there are
multiple layers exist, and only top of these can be modified. So a whiteout
in top layer is used to hide a corresponding file in lower layer, as well
removal of whiteout will make the file appear.
Now in overlayfs, when we rename a file which is exist in lower layer, it
will be copied up to upper if it is not on upper layer yet, and then rename
it on upper layer, source file will be whiteouted to hide corresponding file
in lower layer at the same time.
So in upper layer filesystem, implementation of RENAME_WHITEOUT provide a
atomic operation for stackable filesystem to support rename operation.
There are multiple ways to implement RENAME_WHITEOUT in log of this commit:
7dcf5c3e45 ("xfs: add RENAME_WHITEOUT support") which pointed out by
Dave Chinner.
For now, we just try to follow the way that xfs/ext4 use.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
No matter what the key is valid or not, readdir shows the dir entries correctly.
So, lookup should not failed.
But, we expect further accesses should be denied from open, rename, link, and so
on.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
