ext4: allow readdir()'s of large empty directories to be interrupted

If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to schedu

ext4: allow readdir()'s of large empty directories to be interrupted

If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to scheduler warnings and users
getting irritated when they can't kill a process in the middle of one
of these long-running readdir operations. Fix this by adding checks to
ext4_readdir() and ext4_htree_fill_tree().

This was reverted earlier due to a typo in the original commit where I
experimented with using signal_pending() instead of
fatal_signal_pending(). The test was in the wrong place if we were
going to return signal_pending() since we would end up returning
duplicant entries. See 9f2394c9be47 for a more detailed explanation.

Added fix as suggested by Linus to check for signal_pending() in
in the filldir() functions.

Reported-by: Benjamin LaHaise <bcrl@kvack.org>
Google-Bug-Id: 27880676
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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Revert "ext4: allow readdir()'s of large empty directories to be interrupted"

This reverts commit 1028b55bafb7611dda1d8fed2aeca16a436b7dff.

It's broken: it makes ext4 return an erro

Revert "ext4: allow readdir()'s of large empty directories to be interrupted"

This reverts commit 1028b55bafb7611dda1d8fed2aeca16a436b7dff.

It's broken: it makes ext4 return an error at an invalid point, causing
the readdir wrappers to write the the position of the last successful
directory entry into the position field, which means that the next
readdir will now return that last successful entry _again_.

You can only return fatal errors (that terminate the readdir directory
walk) from within the filesystem readdir functions, the "normal" errors
(that happen when the readdir buffer fills up, for example) happen in
the iterorator where we know the position of the actual failing entry.

I do have a very different patch that does the "signal_pending()"
handling inside the iterator function where it is allowable, but while
that one passes all the sanity checks, I screwed up something like four
times while emailing it out, so I'm not going to commit it today.

So my track record is not good enough, and the stars will have to align
better before that one gets committed. And it would be good to get some
review too, of course, since celestial alignments are always an iffy
debugging model.

IOW, let's just revert the commit that caused the problem for now.

Reported-by: Greg Thelen <gthelen@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
"These changes contains a fix for overlayfs interacting w

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
"These changes contains a fix for overlayfs interacting with some
(badly behaved) dentry code in various file systems. These have been
reviewed by Al and the respective file system mtinainers and are going
through the ext4 tree for convenience.

This also has a few ext4 encryption bug fixes that were discovered in
Android testing (yes, we will need to get these sync'ed up with the
fs/crypto code; I'll take care of that). It also has some bug fixes
and a change to ignore the legacy quota options to allow for xfstests
regression testing of ext4's internal quota feature and to be more
consistent with how xfs handles this case"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: ignore quota mount options if the quota feature is enabled
ext4 crypto: fix some error handling
ext4: avoid calling dquot_get_next_id() if quota is not enabled
ext4: retry block allocation for failed DIO and DAX writes
ext4: add lockdep annotations for i_data_sem
ext4: allow readdir()'s of large empty directories to be interrupted
btrfs: fix crash/invalid memory access on fsync when using overlayfs
ext4 crypto: use dget_parent() in ext4_d_revalidate()
ext4: use file_dentry()
ext4: use dget_parent() in ext4_file_open()
nfs: use file_dentry()
fs: add file_dentry()
ext4 crypto: don't let data integrity writebacks fail with ENOMEM
ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()

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mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possibl

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

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>

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ext4: allow readdir()'s of large empty directories to be interrupted

If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to schedu

ext4: allow readdir()'s of large empty directories to be interrupted

If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to scheduler warnings and users
getting irritated when they can't kill a process in the middle of one
of these long-running readdir operations. Fix this by adding checks to
ext4_readdir() and ext4_htree_fill_tree().

Reported-by: Benjamin LaHaise <bcrl@kvack.org>
Google-Bug-Id: 27880676
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4: in ext4_dir_llseek, check syscall bitness directly

ext4 treats directory offsets differently for 32-bit and 64-bit callers.
Check the caller type using in_compat_syscall, not is_co

ext4: in ext4_dir_llseek, check syscall bitness directly

ext4 treats directory offsets differently for 32-bit and 64-bit callers.
Check the caller type using in_compat_syscall, not is_compat_task. This
changes behavior on SPARC slightly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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ext4: fix memleak in ext4_readdir()

When ext4_bread() fails, fname_crypto_str remains
allocated after return. Fix that.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Si

ext4: fix memleak in ext4_readdir()

When ext4_bread() fails, fname_crypto_str remains
allocated after return. Fix that.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
CC: Dmitry Monakhov <dmonakhov@virtuozzo.com>

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ext4 crypto: revalidate dentry after adding or removing the key

Add a validation check for dentries for encrypted directory to make
sure we're not caching stale data after a key has been

ext4 crypto: revalidate dentry after adding or removing the key

Add a validation check for dentries for encrypted directory to make
sure we're not caching stale data after a key has been added or removed.

Also check to make sure that status of the encryption key is updated
when readdir(2) is executed.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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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, cle

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 <darrick.wong@oracle.com>

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ext4: call out CRC and corruption errors with specific error codes

Instead of overloading EIO for CRC errors and corrupt structures,
return the same error codes that XFS returns for the

ext4: call out CRC and corruption errors with specific error codes

Instead of overloading EIO for CRC errors and corrupt structures,
return the same error codes that XFS returns for the same issues.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4 crypto: make sure the encryption info is initialized on opendir(2)

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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
t

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>

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ext4 crypto: reorganize how we store keys in the inode

This is a pretty massive patch which does a number of different things:

1) The per-inode encryption information is now stored

ext4 crypto: reorganize how we store keys in the inode

This is a pretty massive patch which does a number of different things:

1) The per-inode encryption information is now stored in an allocated
data structure, ext4_crypt_info, instead of directly in the node.
This reduces the size usage of an in-memory inode when it is not
using encryption.

2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode
encryption structure instead. This remove an unnecessary memory
allocation and free for the fname_crypto_ctx as well as allowing us
to reuse the ctfm in a directory for multiple lookups and file
creations.

3) We also cache the inode's policy information in the ext4_crypt_info
structure so we don't have to continually read it out of the
extended attributes.

4) We now keep the keyring key in the inode's encryption structure
instead of releasing it after we are done using it to derive the
per-inode key. This allows us to test to see if the key has been
revoked; if it has, we prevent the use of the derived key and free
it.

5) When an inode is released (or when the derived key is freed), we
will use memset_explicit() to zero out the derived key, so it's not
left hanging around in memory. This implies that when a user logs
out, it is important to first revoke the key, and then unlink it,
and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to
release any decrypted pages and dcache entries from the system
caches.

6) All this, and we also shrink the number of lines of code by around
100. :-)

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4 crypto: don't allocate a page when encrypting/decrypting file names

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4 crypto: simplify and speed up filename encryption

Avoid using SHA-1 when calculating the user-visible filename when the
encryption key is available, and avoid decrypting lots of fil

ext4 crypto: simplify and speed up filename encryption

Avoid using SHA-1 when calculating the user-visible filename when the
encryption key is available, and avoid decrypting lots of filenames
when searching for a directory entry in a directory block.

Change-Id: If4655f144784978ba0305b597bfa1c8d7bb69e63
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4 crypto: enable filename encryption

Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Michael Halcrow <mhalc

ext4 crypto: enable filename encryption

Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4 crypto: teach ext4_htree_store_dirent() to store decrypted filenames

For encrypted directories, we need to pass in a separate parameter for
the decrypted filename, since the directo

ext4 crypto: teach ext4_htree_store_dirent() to store decrypted filenames

For encrypted directories, we need to pass in a separate parameter for
the decrypted filename, since the directory entry contains the
encrypted filename.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4: remove unused header files

Remove unused header files and header files which are included in
ext4.h.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: T

ext4: remove unused header files

Remove unused header files and header files which are included in
ext4.h.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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ext4: convert ext4_bread() to use the ERR_PTR convention

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

ext4: check inline directory before converting

Before converting an inline directory to a regular directory, check
the directory entries to make sure they're not obviously broken.
Th

ext4: check inline directory before converting

Before converting an inline directory to a regular directory, check
the directory entries to make sure they're not obviously broken.
This helps us to avoid a BUG_ON if one of the dirents is trashed.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>

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ext4: remove unused local variable "stored" from ext4_readdir(...)

Remove local variable "stored" from ext4_readdir(...). This variable
gets initialized but is never used inside the func

ext4: remove unused local variable "stored" from ext4_readdir(...)

Remove local variable "stored" from ext4_readdir(...). This variable
gets initialized but is never used inside the function.

Signed-off-by: Giedrius Rekasius <giedrius.rekasius@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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fs/ext4: use rbtree postorder iteration helper instead of opencoding

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iterati

fs/ext4: use rbtree postorder iteration helper instead of opencoding

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Michel Lespinasse <walken@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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ext4: Fix misspellings using 'codespell' tool

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

[readdir] convert ext4

and trim the living hell out bogosities in inline dir case

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

ext4: fix readdir error in the case of inline_data+dir_index

Zach reported a problem that if inline data is enabled, we don't
tell the difference between the offset of '.' and '..'. And

ext4: fix readdir error in the case of inline_data+dir_index

Zach reported a problem that if inline data is enabled, we don't
tell the difference between the offset of '.' and '..'. And a
getdents will fail if the user only want to get '.' and what's worse,
if there is a conversion happens when the user calls getdents
many times, he/she may get the same entry twice.

In theory, a dir block would also fail if it is converted to a
hashed-index based dir since f_pos will become a hash value, not the
real one, but it doesn't happen. And a deep investigation shows that
we uses a hash based solution even for a normal dir if the dir_index
feature is enabled.

So this patch just adds a new htree_inlinedir_to_tree for inline dir,
and if we find that the hash index is supported, we will do like what
we do for a dir block.

Reported-by: Zach Brown <zab@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

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