linux-toradex.git/fs/fat/fat.h, branch v7.2-rc5

fat: avoid stack overflow warning

2026-07-09T22:48:55+00:00

Building the fat kunit tests on with -fsanitize=alignment reveals some
rather excessive stack usage:

fs/fat/fat_test.c: In function 'fat_clus_to_blknr_test':
fs/fat/fat_test.c:33:1: error: the frame size of 4736 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
   33 | }
      | ^
fs/fat/fat_test.c: In function 'fat_get_blknr_offset_test':
fs/fat/fat_test.c:52:1: error: the frame size of 4800 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]

The problem is clearly related to the on-stack copy of a local
msdos_sb_info structure.  Avoid this by making that copy 'static const'
and changing the called functions to accept a constant input.

Link: https://lore.kernel.org/20260515204456.2692208-1-arnd@kernel.org
Fixes: 410002f8139c ("kunit: fat: test cluster and directory i_pos layout helpers")
Signed-off-by: Arnd Bergmann 
Acked-by: OGAWA Hirofumi 
Cc: Christian Brauner 
Cc: Jan Kara 
Cc: Adi Nata 
Cc: David Laight 
Signed-off-by: Andrew Morton

fat: Implement fileattr_get for case sensitivity

2026-05-11T14:50:28+00:00

Report FAT's case sensitivity behavior via the FS_XFLAG_CASEFOLD
and FS_XFLAG_CASENONPRESERVING flags. FAT filesystems are
case-insensitive by default.

MSDOS supports a 'nocase' mount option that enables case-sensitive
behavior; check this option when reporting case sensitivity.

VFAT long filename entries preserve case; without VFAT, only
uppercased 8.3 short names are stored. MSDOS with 'nocase' also
preserves case since the name-formatting code skips upcasing when
'nocase' is set. Check both options when reporting case preservation.

Reviewed-by: Jan Kara 
Reviewed-by: Roland Mainz 
Signed-off-by: Chuck Lever 
Link: https://patch.msgid.link/20260507-case-sensitivity-v14-3-e62cc8200435@oracle.com
Signed-off-by: Christian Brauner

fat: Track metadata bhs in fs-private inode part

2026-03-26T14:03:32+00:00

Track metadata bhs for an inode in fs-private part of the inode.

Signed-off-by: Jan Kara 
Link: https://patch.msgid.link/20260326095354.16340-79-jack@suse.cz
Signed-off-by: Christian Brauner

fs: refactor ->update_time handling

2026-01-12T13:01:32+00:00

Pass the type of update (atime vs c/mtime plus version) as an enum
instead of a set of flags that caused all kinds of confusion.
Because inode_update_timestamps now can't return a modified version
of those flags, return the I_DIRTY_* flags needed to persist the
update, which is what the main caller in generic_update_time wants
anyway, and which is suitable for the other callers that only want
to know if an update happened.

The whole update_time path keeps the flags argument, which will be used
to support non-blocking updates soon even if it is unused, and (the
slightly renamed) inode_update_time also gains the possibility to return
a negative errno to support this.

Signed-off-by: Christoph Hellwig 
Link: https://patch.msgid.link/20260108141934.2052404-6-hch@lst.de
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

fat: cleanup the flags for fat_truncate_time

2026-01-12T13:01:32+00:00

Fat only has a single on-disk timestamp covering ctime and mtime.  Add
fat-specific flags that indicate which timestamp fat_truncate_time should
update to make this more clear.  This allows removing no-op
fat_truncate_time calls with the S_CTIME flag and prepares for removing
the S_* flags.

Signed-off-by: Christoph Hellwig 
Link: https://patch.msgid.link/20260108141934.2052404-5-hch@lst.de
Acked-by: OGAWA Hirofumi 
Signed-off-by: Christian Brauner

fat: Convert to new mount api

2024-07-03T08:48:59+00:00

vfat and msdos share a common set of options, with additional, unique
options for each filesystem.

Each filesystem calls common fc initialization and parsing routines,
with an "is_vfat" parameter. For parsing, if the option is not found
in the common parameter_spec, parsing is retried with the fs-specific
parameter_spec.

This patch leaves nls loading to fill_super, so the codepage and charset
options are not validated as they are requested. This matches current
behavior. It would be possible to test-load as each option is parsed,
but that would make i.e.

mount -o "iocharset=nope,iocharset=iso8859-1"

fail, where it does not fail today because only the last iocharset
option is considered.

The obsolete "conv=" option is set up with an enum of acceptable values;
currently invalid "conv=" options are rejected as such, even though the
option is obsolete, so this patch preserves that behavior.

Signed-off-by: Eric Sandeen 
Link: https://lore.kernel.org/r/a9411b02-5f8e-4e1e-90aa-0c032d66c312@redhat.com
Acked-by: OGAWA Hirofumi 
Signed-off-by: Christian Brauner

fat: move debug into fat_mount_options

2024-07-03T08:48:59+00:00

Move the debug variable into fat_mount_options for consistency and
to facilitate conversion to new mount API.

Signed-off-by: Eric Sandeen 
Link: https://lore.kernel.org/r/f6155247-32ee-4cfe-b808-9102b17f7cd1@redhat.com
Acked-by: OGAWA Hirofumi 
Signed-off-by: Christian Brauner

fs: drop the timespec64 argument from update_time

2023-08-11T07:04:57+00:00

Now that all of the update_time operations are prepared for it, we can
drop the timespec64 argument from the update_time operation. Do that and
remove it from some associated functions like inode_update_time and
inode_needs_update_time.

Signed-off-by: Jeff Layton 
Reviewed-by: Jan Kara 
Message-Id: <20230807-mgctime-v7-8-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner

fs: port ->getattr() to pass mnt_idmap

2023-01-19T08:24:25+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

fs: port ->setattr() to pass mnt_idmap

2023-01-19T08:24:02+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)