xfs: stabilize the dirent name transformation function used for ascii-ci dir hash computation

Back in the old days, the "ascii-ci" feature was created to implement
case-insensitive directory entry l

xfs: stabilize the dirent name transformation function used for ascii-ci dir hash computation

Back in the old days, the "ascii-ci" feature was created to implement
case-insensitive directory entry lookups for latin1-encoded names and
remove the large overhead of Samba's case-insensitive lookup code. UTF8
names were not allowed, but nobody explicitly wrote in the documentation
that this was only expected to work if the system used latin1 names.
The kernel tolower function was selected to prepare names for hashed
lookups.

There's a major discrepancy in the function that computes directory entry
hashes for filesystems that have ASCII case-insensitive lookups enabled.
The root of this is that the kernel and glibc's tolower implementations
have differing behavior for extended ASCII accented characters. I wrote
a program to spit out characters for which the tolower() return value is
different from the input:

glibc tolower:
65:A 66:B 67:C 68:D 69:E 70:F 71:G 72:H 73:I 74:J 75:K 76:L 77:M 78:N
79:O 80:P 81:Q 82:R 83:S 84:T 85:U 86:V 87:W 88:X 89:Y 90:Z

kernel tolower:
65:A 66:B 67:C 68:D 69:E 70:F 71:G 72:H 73:I 74:J 75:K 76:L 77:M 78:N
79:O 80:P 81:Q 82:R 83:S 84:T 85:U 86:V 87:W 88:X 89:Y 90:Z 192:À 193:Á
194:Â 195:Ã 196:Ä 197:Å 198:Æ 199:Ç 200:È 201:É 202:Ê 203:Ë 204:Ì 205:Í
206:Î 207:Ï 208:Ð 209:Ñ 210:Ò 211:Ó 212:Ô 213:Õ 214:Ö 215:× 216:Ø 217:Ù
218:Ú 219:Û 220:Ü 221:Ý 222:Þ

Which means that the kernel and userspace do not agree on the hash value
for a directory filename that contains those higher values. The hash
values are written into the leaf index block of directories that are
larger than two blocks in size, which means that xfs_repair will flag
these directories as having corrupted hash indexes and rewrite the index
with hash values that the kernel now will not recognize.

Because the ascii-ci feature is not frequently enabled and the kernel
touches filesystems far more frequently than xfs_repair does, fix this
by encoding the kernel's toupper predicate and tolower functions into
libxfs. Give the new functions less provocative names to make it really
obvious that this is a pre-hash name preparation function, and nothing
else. This change makes userspace's behavior consistent with the
kernel.

Found by auditing obfuscate_name in xfs_metadump as part of working on
parent pointers, wondering how it could possibly work correctly with ci
filesystems, writing a test tool to create a directory with
hash-colliding names, and watching xfs_repair flag it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: rearrange the logic and remove the broken comment for xfs_dir2_isxx

xfs_dir2_isleaf is used to see if the directory is a single-leaf
form directory instead, as commented right above the functio

xfs: rearrange the logic and remove the broken comment for xfs_dir2_isxx

xfs_dir2_isleaf is used to see if the directory is a single-leaf
form directory instead, as commented right above the function.

Besides getting rid of the broken comment, we rearrange the logic by
converting everything over to standard formatting and conventions,
at the same time, to make it easier to understand and self documenting.

Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

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xfs: constify xfs_name_dotdot

The symbol xfs_name_dotdot is a global variable that the xfs codebase
uses here and there to look up directory dotdot entries. Currently it's
a non-const variable, whi

xfs: constify xfs_name_dotdot

The symbol xfs_name_dotdot is a global variable that the xfs codebase
uses here and there to look up directory dotdot entries. Currently it's
a non-const variable, which means that it's a mutable global variable.
So far nobody's abused this to cause problems, but let's use the
compiler to enforce that.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: constify the name argument to various directory functions

Various directory functions do not modify their @name parameter,
so mark it const to make that clear. This will enable us to mark
the

xfs: constify the name argument to various directory functions

Various directory functions do not modify their @name parameter,
so mark it const to make that clear. This will enable us to mark
the global xfs_name_dotdot variable as const to prevent mischief.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: fix an ABBA deadlock in xfs_rename

When overlayfs is running on top of xfs and the user unlinks a file in
the overlay, overlayfs will create a whiteout inode and ask xfs to
"rename" the whiteou

xfs: fix an ABBA deadlock in xfs_rename

When overlayfs is running on top of xfs and the user unlinks a file in
the overlay, overlayfs will create a whiteout inode and ask xfs to
"rename" the whiteout file atop the one being unlinked. If the file
being unlinked loses its one nlink, we then have to put the inode on the
unlinked list.

This requires us to grab the AGI buffer of the whiteout inode to take it
off the unlinked list (which is where whiteouts are created) and to grab
the AGI buffer of the file being deleted. If the whiteout was created
in a higher numbered AG than the file being deleted, we'll lock the AGIs
in the wrong order and deadlock.

Therefore, grab all the AGI locks we think we'll need ahead of time, and
in order of increasing AG number per the locking rules.

Reported-by: wenli xie <wlxie7296@gmail.com>
Fixes: 93597ae8dac0 ("xfs: Fix deadlock between AGI and AGF when target_ip exists in xfs_rename()")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

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xfs: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in header files
related to XFS File System support. For C header files
Documentation/proc

xfs: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in header files
related to XFS File System support. For C header files
Documentation/process/license-rules.rst mandates C-like comments.
(opposed to C source files where C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: Fix deadlock between AGI and AGF when target_ip exists in xfs_rename()

When target_ip exists in xfs_rename(), the xfs_dir_replace() call may
need to hold the AGF lock to allocate more blocks, a

xfs: Fix deadlock between AGI and AGF when target_ip exists in xfs_rename()

When target_ip exists in xfs_rename(), the xfs_dir_replace() call may
need to hold the AGF lock to allocate more blocks, and then invoking
the xfs_droplink() call to hold AGI lock to drop target_ip onto the
unlinked list, so we get the lock order AGF->AGI. This would break the
ordering constraint on AGI and AGF locking - inode allocation locks
the AGI, then can allocate a new extent for new inodes, locking the
AGF after the AGI.

In this patch we check whether the replace operation need more
blocks firstly. If so, acquire the agi lock firstly to preserve
locking order(AGI/AGF). Actually, the locking order problem only
occurs when we are locking the AGI/AGF of the same AG. For multiple
AGs the AGI lock will be released after the transaction committed.

Signed-off-by: kaixuxia <kaixuxia@tencent.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: reword the comment]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: merge xfs_dir2_data_freescan and xfs_dir2_data_freescan_int

There is no real need for xfs_dir2_data_freescan wrapper, so rename
xfs_dir2_data_freescan_int to xfs_dir2_data_freescan and let the

xfs: merge xfs_dir2_data_freescan and xfs_dir2_data_freescan_int

There is no real need for xfs_dir2_data_freescan wrapper, so rename
xfs_dir2_data_freescan_int to xfs_dir2_data_freescan and let the
callers dereference the mount pointer from the inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the now unused dir ops infrastructure

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@or

xfs: remove the now unused dir ops infrastructure

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->data_get_ftype and ->data_put_ftype

Replace the ->data_get_ftype and ->data_put_ftype dir ops methods with
directly called xfs_dir2_data_get_ftype and xfs_dir2_data_put_ftype
hel

xfs: devirtualize ->data_get_ftype and ->data_put_ftype

Replace the ->data_get_ftype and ->data_put_ftype dir ops methods with
directly called xfs_dir2_data_get_ftype and xfs_dir2_data_put_ftype
helpers that takes care of the differences between the directory format
with and without the file type field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->data_bestfree_p

Replace the ->data_bestfree_p dir ops method with a directly called
xfs_dir2_data_bestfree_p helper that takes care of the differences
between the v4 and v5 on-di

xfs: devirtualize ->data_bestfree_p

Replace the ->data_bestfree_p dir ops method with a directly called
xfs_dir2_data_bestfree_p helper that takes care of the differences
between the v4 and v5 on-disk format.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: move the dir2 data block fixed offsets to struct xfs_da_geometry

Move the data block fixed offsets towards our structure for dir/attr
geometry parameters.

Signed-off-by: Christoph Hellwig <hch

xfs: move the dir2 data block fixed offsets to struct xfs_da_geometry

Move the data block fixed offsets towards our structure for dir/attr
geometry parameters.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->data_entry_tag_p

Replace the ->data_entry_tag_p dir ops method with a directly called
xfs_dir2_data_entry_tag_p helper that takes care of the differences
between the directory fo

xfs: devirtualize ->data_entry_tag_p

Replace the ->data_entry_tag_p dir ops method with a directly called
xfs_dir2_data_entry_tag_p helper that takes care of the differences
between the directory format with and without the file type field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->data_entsize

Replace the ->data_entsize dir ops method with a directly called
xfs_dir2_data_entsize helper that takes care of the differences between
the directory format with an

xfs: devirtualize ->data_entsize

Replace the ->data_entsize dir ops method with a directly called
xfs_dir2_data_entsize helper that takes care of the differences between
the directory format with and without the file type field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: replace xfs_dir3_data_endp with xfs_dir3_data_end_offset

All the callers really want an offset into the buffer, so adopt
the helper to return that instead.

Signed-off-by: Christoph Hellwig <hc

xfs: replace xfs_dir3_data_endp with xfs_dir3_data_end_offset

All the callers really want an offset into the buffer, so adopt
the helper to return that instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the now unused ->data_entry_p method

Now that all users use the data_entry_offset field this method is
unused and can be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-

xfs: remove the now unused ->data_entry_p method

Now that all users use the data_entry_offset field this method is
unused and can be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the ->data_unused_p method

Replace the two users of the ->data_unused_p dir ops method with a
direct calculation using ->data_entry_offset, and clean them up a bit.
xfs_dir2_sf_to_block

xfs: remove the ->data_unused_p method

Replace the two users of the ->data_unused_p dir ops method with a
direct calculation using ->data_entry_offset, and clean them up a bit.
xfs_dir2_sf_to_block already had an offset variable containing the
value of ->data_entry_offset, which we are now reusing to make it
clear that the initial freespace entry is at the same place that
we later fill in the 1 entry, and in xfs_dir3_data_init the function
is cleaned up a bit to keep the initialization of fields of a given
structure close to each other, and to avoid a local variable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the ->data_dot_entry_p and ->data_dotdot_entry_p methods

The only user of the ->data_dot_entry_p and ->data_dotdot_entry_p
methods is the xfs_dir2_sf_to_block function that builds block

xfs: remove the ->data_dot_entry_p and ->data_dotdot_entry_p methods

The only user of the ->data_dot_entry_p and ->data_dotdot_entry_p
methods is the xfs_dir2_sf_to_block function that builds block format
directorys from a short form directory. It already uses pointer
arithmetics with a offset variable to do so for the real entries in
the directory, so switch the generation of the . and .. entries to
the same scheme, and clean up some of the later pointer arithmetics
to use bp->b_addr directly as well and avoid some casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the data_dotdot_offset field in struct xfs_dir_ops

The data_dotdot_offset value is always equal to data_entry_offset plus
the fixed size of the "." entry. Right now calculating that fix

xfs: remove the data_dotdot_offset field in struct xfs_dir_ops

The data_dotdot_offset value is always equal to data_entry_offset plus
the fixed size of the "." entry. Right now calculating that fixed size
requires an indirect call, but by the end of this series it will be
an inline function that can be constant folded.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the data_dot_offset field in struct xfs_dir_ops

The data_dot_offset value is always equal to data_entry_offset given
that "." is always the first entry in the directory.

Signed-off-by:

xfs: remove the data_dot_offset field in struct xfs_dir_ops

The data_dot_offset value is always equal to data_entry_offset given
that "." is always the first entry in the directory.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove the unused ->data_first_entry_p method

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@o

xfs: remove the unused ->data_first_entry_p method

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->sf_get_ftype and ->sf_put_ftype

Replace the ->sf_get_ftype and ->sf_put_ftype dir ops methods with
directly called xfs_dir2_sf_get_ftype and xfs_dir2_sf_put_ftype helpers
that ta

xfs: devirtualize ->sf_get_ftype and ->sf_put_ftype

Replace the ->sf_get_ftype and ->sf_put_ftype dir ops methods with
directly called xfs_dir2_sf_get_ftype and xfs_dir2_sf_put_ftype helpers
that takes care of the differences between the directory format with and
without the file type field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->sf_get_ino and ->sf_put_ino

Replace the ->sf_get_ino and ->sf_put_ino dir ops methods with directly
called xfs_dir2_sf_get_ino and xfs_dir2_sf_put_ino helpers that take care
of t

xfs: devirtualize ->sf_get_ino and ->sf_put_ino

Replace the ->sf_get_ino and ->sf_put_ino dir ops methods with directly
called xfs_dir2_sf_get_ino and xfs_dir2_sf_put_ino helpers that take care
of the difference between the directory format with and without the file
type field. Also move xfs_dir2_sf_get_parent_ino and
xfs_dir2_sf_put_parent_ino to xfs_dir2_sf.c with the rest of the
low-level short form entry handling and use XFS_MAXINUMBER istead of
opencoded constants.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->sf_entsize and ->sf_nextentry

Just check for file-type enabled directories directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@ora

xfs: devirtualize ->sf_entsize and ->sf_nextentry

Just check for file-type enabled directories directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: devirtualize ->sf_get_parent_ino and ->sf_put_parent_ino

The parent inode handling is the same for all directory format variants,
just use direct calls instead of going through a pointless indi

xfs: devirtualize ->sf_get_parent_ino and ->sf_put_parent_ino

The parent inode handling is the same for all directory format variants,
just use direct calls instead of going through a pointless indirect
call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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