ovl: make consistent use of OVL_FS()

Always use OVL_FS() to retrieve the corresponding struct ovl_fs from a
struct super_block.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andre

ovl: make consistent use of OVL_FS()

Always use OVL_FS() to retrieve the corresponding struct ovl_fs from a
struct super_block.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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ovl: auto generate uuid for new overlay filesystems

Add a new mount option uuid=auto, which is the default.

If a persistent UUID xattr is found it is used.

Otherwise, an existing ovelrayfs with co

ovl: auto generate uuid for new overlay filesystems

Add a new mount option uuid=auto, which is the default.

If a persistent UUID xattr is found it is used.

Otherwise, an existing ovelrayfs with copied up subdirs in upper dir
that was never mounted with uuid=on retains the null UUID.

A new overlayfs with no copied up subdirs, generates the persistent UUID
on first mount.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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ovl: store persistent uuid/fsid with uuid=on

With uuid=on, store a persistent uuid in xattr on the upper dir to
give the overlayfs instance a persistent identifier.

This also makes f_fsid persisten

ovl: store persistent uuid/fsid with uuid=on

With uuid=on, store a persistent uuid in xattr on the upper dir to
give the overlayfs instance a persistent identifier.

This also makes f_fsid persistent and more reliable for reporting
fid info in fanotify events.

uuid=on is not supported on non-upper overlayfs or with upper fs
that does not support xattrs.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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ovl: Handle verity during copy-up

During regular metacopy, if lowerdata file has fs-verity enabled, and
the verity option is enabled, we add the digest to the metacopy xattr.

If verity is required,

ovl: Handle verity during copy-up

During regular metacopy, if lowerdata file has fs-verity enabled, and
the verity option is enabled, we add the digest to the metacopy xattr.

If verity is required, and lowerdata does not have fs-verity enabled,
fall back to full copy-up (or the generated metacopy would not
validate).

Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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ovl: Validate verity xattr when resolving lowerdata

The new digest field in the metacopy xattr is used during lookup to
record whether the header contained a digest in the OVL_HAS_DIGEST
flags.

Whe

ovl: Validate verity xattr when resolving lowerdata

The new digest field in the metacopy xattr is used during lookup to
record whether the header contained a digest in the OVL_HAS_DIGEST
flags.

When accessing file data the first time, if OVL_HAS_DIGEST is set, we
reload the metadata and check that the source lowerdata inode matches
the specified digest in it (according to the enabled verity
options). If the verity check passes we store this info in the inode
flags as OVL_VERIFIED_DIGEST, so that we can avoid doing it again if
the inode remains in memory.

The verification is done in ovl_maybe_validate_verity() which needs to
be called in the same places as ovl_maybe_lookup_lowerdata(), so there
is a new ovl_verify_lowerdata() helper that calls these in the right
order, and all current callers of ovl_maybe_lookup_lowerdata() are
changed to call it instead.

Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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ovl: Add versioned header for overlay.metacopy xattr

Historically overlay.metacopy was a zero-size xattr, and it's
existence marked a metacopy file. This change adds a versioned header
with a flag f

ovl: Add versioned header for overlay.metacopy xattr

Historically overlay.metacopy was a zero-size xattr, and it's
existence marked a metacopy file. This change adds a versioned header
with a flag field, a length and a digest. The initial use-case of this
will be for validating a fs-verity digest, but the flags field could
also be used later for other new features.

ovl_check_metacopy_xattr() now returns the size of the xattr,
emulating a size of OVL_METACOPY_MIN_SIZE for empty xattrs to
distinguish it from the no-xattr case.

Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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overlayfs: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_cti

overlayfs: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-64-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

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ovl: store enum redirect_mode in config instead of a string

Do all the logic to set the mode during mount options parsing and
do not keep the option string around.

Use a constant_table to translate

ovl: store enum redirect_mode in config instead of a string

Do all the logic to set the mode during mount options parsing and
do not keep the option string around.

Use a constant_table to translate from enum redirect mode to string
in preperation for new mount api option parsing.

The mount option "off" is translated to either "follow" or "nofollow",
depending on the "redirect_always_follow" build/module config, so
in effect, there are only three possible redirect modes.

This results in a minor change to the string that is displayed
in show_options() - when redirect_dir is enabled by default and the user
mounts with the option "redirect_dir=off", instead of displaying the mode
"redirect_dir=off" in show_options(), the displayed mode will be either
"redirect_dir=follow" or "redirect_dir=nofollow", depending on the value
of "redirect_always_follow" build/module config.

The displayed mode reflects the effective mode, so mounting overlayfs
again with the dispalyed redirect_dir option will result with the same
effective and displayed mode.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>

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ovl: implement lazy lookup of lowerdata in data-only layers

Defer lookup of lowerdata in the data-only layers to first data access
or before copy up.

We perform lowerdata lookup before copy up even

ovl: implement lazy lookup of lowerdata in data-only layers

Defer lookup of lowerdata in the data-only layers to first data access
or before copy up.

We perform lowerdata lookup before copy up even if copy up is metadata
only copy up. We can further optimize this lookup later if needed.

We do best effort lazy lookup of lowerdata for d_real_inode(), because
this interface does not expect errors. The only current in-tree caller
of d_real_inode() is trace_uprobe and this caller is likely going to be
followed reading from the file, before placing uprobes on offset within
the file, so lowerdata should be available when setting the uprobe.

Tested-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: prepare for lazy lookup of lowerdata inode

Make the code handle the case of numlower > 1 and missing lowerdata
dentry gracefully.

Missing lowerdata dentry is an indication for lazy lookup of l

ovl: prepare for lazy lookup of lowerdata inode

Make the code handle the case of numlower > 1 and missing lowerdata
dentry gracefully.

Missing lowerdata dentry is an indication for lazy lookup of lowerdata
and in that case the lowerdata_redirect path is stored in ovl_inode.

Following commits will defer lookup and perform the lazy lookup on
access.

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: prepare to store lowerdata redirect for lazy lowerdata lookup

Prepare to allow ovl_lookup() to leave the last entry in a non-dir
lowerstack empty to signify lazy lowerdata lookup.

In this case

ovl: prepare to store lowerdata redirect for lazy lowerdata lookup

Prepare to allow ovl_lookup() to leave the last entry in a non-dir
lowerstack empty to signify lazy lowerdata lookup.

In this case, ovl_lookup() stores the redirect path from metacopy to
lowerdata in ovl_inode, which is going to be used later to perform the
lazy lowerdata lookup.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: deduplicate lowerdata and lowerstack[]

The ovl_inode contains a copy of lowerdata in lowerstack[], so the
lowerdata inode member can be removed.

Use accessors ovl_lowerdata*() to get the lower

ovl: deduplicate lowerdata and lowerstack[]

The ovl_inode contains a copy of lowerdata in lowerstack[], so the
lowerdata inode member can be removed.

Use accessors ovl_lowerdata*() to get the lowerdata whereever the member
was accessed directly.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: deduplicate lowerpath and lowerstack[]

The ovl_inode contains a copy of lowerpath in lowerstack[0], so the
lowerpath member can be removed.

Use accessor ovl_lowerpath() to get the lowerpath wh

ovl: deduplicate lowerpath and lowerstack[]

The ovl_inode contains a copy of lowerpath in lowerstack[0], so the
lowerpath member can be removed.

Use accessor ovl_lowerpath() to get the lowerpath whereever the member
was accessed directly.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: move ovl_entry into ovl_inode

The lower stacks of all the ovl inode aliases should be identical
and there is redundant information in ovl_entry and ovl_inode.

Move lowerstack into ovl_inode an

ovl: move ovl_entry into ovl_inode

The lower stacks of all the ovl inode aliases should be identical
and there is redundant information in ovl_entry and ovl_inode.

Move lowerstack into ovl_inode and keep only the OVL_E_FLAGS
per overlay dentry.

Following patches will deduplicate redundant ovl_inode fields.

Note that for pure upper and negative dentries, OVL_E(dentry) may be
NULL now, so it is imporatnt to use the ovl_numlower() accessor.

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: factor out ovl_free_entry() and ovl_stack_*() helpers

In preparation for moving lowerstack into ovl_inode.

Note that in ovl_lookup() the temp stack dentry refs are now cloned
into the final ov

ovl: factor out ovl_free_entry() and ovl_stack_*() helpers

In preparation for moving lowerstack into ovl_inode.

Note that in ovl_lookup() the temp stack dentry refs are now cloned
into the final ovl_lowerstack instead of being transferred, so cleanup
always needs to call ovl_stack_free(stack).

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: use ovl_numlower() and ovl_lowerstack() accessors

This helps fortify against dereferencing a NULL ovl_entry,
before we move the ovl_entry reference into ovl_inode.

Reviewed-by: Alexander Larss

ovl: use ovl_numlower() and ovl_lowerstack() accessors

This helps fortify against dereferencing a NULL ovl_entry,
before we move the ovl_entry reference into ovl_inode.

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: use OVL_E() and OVL_E_FLAGS() accessors

Instead of open coded instances, because we are about to split
the two apart.

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Gold

ovl: use OVL_E() and OVL_E_FLAGS() accessors

Instead of open coded instances, because we are about to split
the two apart.

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: update of dentry revalidate flags after copy up

After copy up, we may need to update d_flags if upper dentry is on a
remote fs and lower dentries are not.

Add helpers to allow incremental upda

ovl: update of dentry revalidate flags after copy up

After copy up, we may need to update d_flags if upper dentry is on a
remote fs and lower dentries are not.

Add helpers to allow incremental update of the revalidate flags.

Fixes: bccece1ead36 ("ovl: allow remote upper")
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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ovl: let helper ovl_i_path_real() return the realinode

Let helper ovl_i_path_real() return the realinode to prepare for
checking non-null realinode in RCU walking path.

[msz] Use d_inode_rcu() sinc

ovl: let helper ovl_i_path_real() return the realinode

Let helper ovl_i_path_real() return the realinode to prepare for
checking non-null realinode in RCU walking path.

[msz] Use d_inode_rcu() since we are depending on the consitency
between dentry and inode being non-NULL in an RCU setting.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Fixes: ffa5723c6d25 ("ovl: store lower path in ovl_inode")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

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fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap

Convert to struct mnt_idmap.
Remove legacy file_mnt_user_ns() and mnt_user_ns().

Last cycle we merged the necessary infrastructure in
256c8aed2b42

fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap

Convert to struct mnt_idmap.
Remove legacy file_mnt_user_ns() and mnt_user_ns().

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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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fs: port inode_owner_or_capable() to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This

fs: port inode_owner_or_capable() to mnt_idmap

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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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fs: port ->permission() to pass mnt_idmap

Convert to struct mnt_idmap.

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

fs: port ->permission() to pass mnt_idmap

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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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ovl: use inode instead of dentry where possible

Passing dentry to some helpers is unnecessary. Simplify these cases.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

ovl: port to vfs{g,u}id_t and associated helpers

A while ago we introduced a dedicated vfs{g,u}id_t type in commit
1e5267cd0895 ("mnt_idmapping: add vfs{g,u}id_t"). We already switched
over a good p

ovl: port to vfs{g,u}id_t and associated helpers

A while ago we introduced a dedicated vfs{g,u}id_t type in commit
1e5267cd0895 ("mnt_idmapping: add vfs{g,u}id_t"). We already switched
over a good part of the VFS. Ultimately we will remove all legacy
idmapped mount helpers that operate only on k{g,u}id_t in favor of the
new type safe helpers that operate on vfs{g,u}id_t.

Cc: Seth Forshee (Digital Ocean) <sforshee@kernel.org>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

show more ...

ovl: port to vfs{g,u}id_t and associated helpers

A while ago we introduced a dedicated vfs{g,u}id_t type in commit
1e5267cd0895 ("mnt_idmapping: add vfs{g,u}id_t"). We already switched
over a good p

ovl: port to vfs{g,u}id_t and associated helpers

A while ago we introduced a dedicated vfs{g,u}id_t type in commit
1e5267cd0895 ("mnt_idmapping: add vfs{g,u}id_t"). We already switched
over a good part of the VFS. Ultimately we will remove all legacy
idmapped mount helpers that operate only on k{g,u}id_t in favor of the
new type safe helpers that operate on vfs{g,u}id_t.

Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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