linux-stable.git/fs/stat.c, branch v5.18.2

stat: fix inconsistency between struct stat and struct compat_stat

2022-04-12T23:35:08+00:00

struct stat (defined in arch/x86/include/uapi/asm/stat.h) has 32-bit
st_dev and st_rdev; struct compat_stat (defined in
arch/x86/include/asm/compat.h) has 16-bit st_dev and st_rdev followed by
a 16-bit padding.

This patch fixes struct compat_stat to match struct stat.

[ Historical note: the old x86 'struct stat' did have that 16-bit field
  that the compat layer had kept around, but it was changes back in 2003
  by "struct stat - support larger dev_t":

    https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=e95b2065677fe32512a597a79db94b77b90c968d

  and back in those days, the x86_64 port was still new, and separate
  from the i386 code, and had already picked up the old version with a
  16-bit st_dev field ]

Note that we can't change compat_dev_t because it is used by
compat_loop_info.

Also, if the st_dev and st_rdev values are 32-bit, we don't have to use
old_valid_dev to test if the value fits into them.  This fixes
-EOVERFLOW on filesystems that are on NVMe because NVMe uses the major
number 259.

Signed-off-by: Mikulas Patocka 
Cc: Andreas Schwab 
Cc: Matthew Wilcox 
Cc: Christoph Hellwig 
Signed-off-by: Linus Torvalds

io-uring: Make statx API stable

2022-03-10T16:33:55+00:00

One of the key architectual tenets is to keep the parameters for
io-uring stable. After the call has been submitted, its value can
be changed. Unfortunaltely this is not the case for the current statx
implementation.

IO-Uring change:
This changes replaces the const char * filename pointer in the io_statx
structure with a struct filename *. In addition it also creates the
filename object during the prepare phase.

With this change, the opcode also needs to invoke cleanup, so the
filename object gets freed after processing the request.

fs change:
This replaces the const char* __user filename parameter in the two
functions do_statx and vfs_statx with a struct filename *. In addition
to be able to correctly construct a filename object a new helper
function getname_statx_lookup_flags is introduced. The function makes
sure that do_statx and vfs_statx is invoked with the correct lookup flags.

Signed-off-by: Stefan Roesch 
Link: https://lore.kernel.org/r/20220225185326.1373304-2-shr@fb.com
Signed-off-by: Jens Axboe

fs: add generic helper for filling statx attribute flags

2021-08-17T09:47:43+00:00

The immutable and append-only properties on an inode are published on
the inode's i_flags and enforced by the VFS.

Create a helper to fill the corresponding STATX_ATTR_ flags in the kstat
structure from the inode's i_flags.

Only orange was converted to use this helper.
Other filesystems could use it in the future.

Suggested-by: Miklos Szeredi 
Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

fs: fix reporting supported extra file attributes for statx()

2021-04-18T03:03:50+00:00

statx(2) notes that any attribute that is not indicated as supported
by stx_attributes_mask has no usable value.  Commits 801e523796004
("fs: move generic stat response attr handling to vfs_getattr_nosec")
and 712b2698e4c02 ("fs/stat: Define DAX statx attribute") sets
STATX_ATTR_AUTOMOUNT and STATX_ATTR_DAX, respectively, without setting
stx_attributes_mask, which can cause xfstests generic/532 to fail.

Fix this in the same way as commit 1b9598c8fb99 ("xfs: fix reporting
supported extra file attributes for statx()")

Fixes: 801e523796004 ("fs: move generic stat response attr handling to vfs_getattr_nosec")
Fixes: 712b2698e4c02 ("fs/stat: Define DAX statx attribute")
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o

fs: make helpers idmap mount aware

2021-01-24T13:27:20+00:00

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig 
Cc: David Howells 
Cc: Al Viro 
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner

stat: handle idmapped mounts

2021-01-24T13:27:17+00:00

The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig 
Cc: David Howells 
Cc: Al Viro 
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig 
Reviewed-by: James Morris 
Signed-off-by: Christian Brauner

fs: remove KSTAT_QUERY_FLAGS

2020-09-27T02:55:05+00:00

KSTAT_QUERY_FLAGS expands to AT_STATX_SYNC_TYPE, which itself already
is a mask.  Remove the double name, especially given that the prefix
is a little confusing vs the normal AT_* flags.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: remove vfs_stat_set_lookup_flags

2020-09-27T02:55:05+00:00

The function really obsfucates checking for valid flags and setting the
lookup flags.  The fact that it returns -EINVAL through and unsigned
return value, which is then used as boolean really doesn't help either.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: move vfs_fstatat out of line

2020-09-27T02:55:05+00:00

This allows to keep vfs_statx static in fs/stat.c to prepare for the following
changes.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: remove vfs_statx_fd

2020-09-27T02:55:05+00:00

vfs_statx_fd is only used to implement vfs_fstat.  Remove vfs_statx_fd
and just implement vfs_fstat directly.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro