kernel/linux.git/fs/zonefs/super.c, branch v6.4

Merge tag 'zonefs-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs

2023-02-22T22:11:54+00:00

Pull zonefs updates from Damien Le Moal: - Reorganize zonefs code to split file related operations to a new fs/zonefs/file.c file (me) - Modify zonefs to use dynamically allocated inodes and dentries (using the inode and dentry caches) instead of statically allocating everything on mount. This saves a significant amount of memory for very large zoned block devices with 10s of thousands of zones (me) - Make zonefs_sb_ktype a const struct kobj_type (Thomas) * tag 'zonefs-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs: zonefs: make kobj_type structure constant zonefs: Cache zone group directory inodes zonefs: Dynamically create file inodes when needed zonefs: Separate zone information from inode information zonefs: Reduce struct zonefs_inode_info size zonefs: Simplify IO error handling zonefs: Reorganize code

Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

2023-02-20T19:53:11+00:00

Pull vfs idmapping updates from Christian Brauner: - Last cycle we introduced the dedicated struct mnt_idmap type for mount idmapping and the required infrastucture in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). As promised in last cycle's pull request message this converts everything to rely on 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 relevant on the mount level. Especially for non-vfs developers without detailed knowledge in this area this was a potential source for bugs. This finishes the conversion. Instead of passing the plain namespace around this updates all places that currently take a pointer to a mnt_userns with a pointer to struct mnt_idmap. Now that the conversion is done all helpers down to the really low-level helpers only accept a struct mnt_idmap argument instead of two namespace arguments. Conflating mount and other idmappings will now cause the compiler to complain loudly thus eliminating the possibility of any bugs. This makes it impossible for filesystem developers to mix up mount and filesystem idmappings as they are two distinct types and require distinct helpers that cannot be used interchangeably. Everything associated with struct mnt_idmap is moved into a single separate file. With that change no code can poke around in struct mnt_idmap. It can only be interacted with through dedicated helpers. That means all filesystems are and all of the vfs is completely oblivious to the actual implementation of idmappings. We are now also able to extend struct mnt_idmap as we see fit. For example, we can decouple it completely from namespaces for users that don't require or don't want to use them at all. We can also extend the concept of idmappings so we can cover filesystem specific requirements. In combination with the vfs{g,u}id_t work we finished in v6.2 this makes this feature substantially more robust and thus difficult to implement wrong by a given filesystem and also protects the vfs. - Enable idmapped mounts for tmpfs and fulfill a longstanding request. A long-standing request from users had been to make it possible to create idmapped mounts for tmpfs. For example, to share the host's tmpfs mount between multiple sandboxes. This is a prerequisite for some advanced Kubernetes cases. Systemd also has a range of use-cases to increase service isolation. And there are more users of this. However, with all of the other work going on this was way down on the priority list but luckily someone other than ourselves picked this up. As usual the patch is tiny as all the infrastructure work had been done multiple kernel releases ago. In addition to all the tests that we already have I requested that Rodrigo add a dedicated tmpfs testsuite for idmapped mounts to xfstests. It is to be included into xfstests during the v6.3 development cycle. This should add a slew of additional tests. * tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits) shmem: support idmapped mounts for tmpfs fs: move mnt_idmap fs: port vfs{g,u}id helpers to mnt_idmap fs: port fs{g,u}id helpers to mnt_idmap fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap fs: port i_{g,u}id_{needs_}update() to mnt_idmap quota: port to mnt_idmap fs: port privilege checking helpers to mnt_idmap fs: port inode_owner_or_capable() to mnt_idmap fs: port inode_init_owner() to mnt_idmap fs: port acl to mnt_idmap fs: port xattr to mnt_idmap fs: port ->permission() to pass mnt_idmap fs: port ->fileattr_set() to pass mnt_idmap fs: port ->set_acl() to pass mnt_idmap fs: port ->get_acl() to pass mnt_idmap fs: port ->tmpfile() to pass mnt_idmap fs: port ->rename() to pass mnt_idmap fs: port ->mknod() to pass mnt_idmap fs: port ->mkdir() to pass mnt_idmap ...

zonefs: Cache zone group directory inodes

2023-01-23T00:25:51+00:00

Since looking up any zone file inode requires looking up first the inode for the directory representing the zone group of the file, ensuring that the zone group inodes are always cached is desired. To do so, take an extra reference on the zone groups directory inodes on mount, thus avoiding the eviction of these inodes from the inode cache until the volume is unmounted. Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn

zonefs: Dynamically create file inodes when needed

2023-01-23T00:25:51+00:00

Allocating and initializing all inodes and dentries for all files results in a very large memory usage with high capacity zoned block devices. For instance, with a 26 TB SMR HDD with over 96000 zones, mounting the disk with zonefs results in about 130 MB of memory used, the vast majority of this space being used for vfs inodes and dentries. However, since a user will rarely access all zones at the same time, dynamically creating file inodes and dentries on demand, similarly to regular file systems, can significantly reduce memory usage. This patch modifies mount processing to not create the inodes and dentries for zone files. Instead, the directory inode operation zonefs_lookup() and directory file operation zonefs_readdir() are introduced to allocate and initialize inodes on-demand using the helper functions zonefs_get_dir_inode() and zonefs_get_zgroup_inode(). Implementation of these functions is simple, relying on the static nature of zonefs directories and files. Directory inodes are linked to the volume zone groups (struct zonefs_zone_group) they represent by using the directory inode i_private field. This simplifies the implementation of the lookup and readdir operations. Unreferenced zone file inodes can be evicted from the inode cache at any time. In such case, the only inode information that cannot be recreated from the zone information that is saved in the zone group data structures attached to the volume super block is the inode uid, gid and access rights. These values may have been changed by the user. To keep these attributes for the life time of the mount, as before, the inode mode, uid and gid are saved in the inode zone information and the saved values are used to initialize regular file inodes when an inode lookup happens. The zone information mode, uid and gid are initialized in zonefs_init_zgroup() using the default values. With these changes, the static minimal memory usage of a zonefs volume is mostly reduced to the array of zone information for each zone group. For the 26 TB SMR hard-disk mentioned above, the memory usage after mount becomes about 5.4 MB, a reduction by a factor of 24 from the initial 130 MB memory use. Co-developed-by: Jorgen Hansen Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn

zonefs: Separate zone information from inode information

2023-01-23T00:25:51+00:00

In preparation for adding dynamic inode allocation, separate an inode zone information from the zonefs inode structure. The new data structure zonefs_zone is introduced to store in memory information about a zone that must be kept throughout the lifetime of the device mount. Linking between a zone file inode and its zone information is done by setting the inode i_private field to point to a struct zonefs_zone. Using the i_private pointer avoids the need for adding a pointer in struct zonefs_inode_info. Beside the vfs inode, this structure is reduced to a mutex and a write open counter. One struct zonefs_zone is created per file inode on mount. These structures are organized in an array using the new struct zonefs_zone_group data structure to represent zone groups. The zonefs_zone arrays are indexed per file number (the index of a struct zonefs_zone in its array directly gives the file number/name for that zone file inode). Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn

zonefs: Reduce struct zonefs_inode_info size

2023-01-23T00:25:51+00:00

Instead of using the i_ztype field in struct zonefs_inode_info to indicate the zone type of an inode, introduce the new inode flag ZONEFS_ZONE_CNV to be set in the i_flags field of struct zonefs_inode_info to identify conventional zones. If this flag is not set, the zone of an inode is considered to be a sequential zone. The helpers zonefs_zone_is_cnv(), zonefs_zone_is_seq(), zonefs_inode_is_cnv() and zonefs_inode_is_seq() are introduced to simplify testing the zone type of a struct zonefs_inode_info and of a struct inode. Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn

zonefs: Simplify IO error handling

2023-01-23T00:25:51+00:00

Simplify zonefs_check_zone_condition() by moving the code that changes an inode access rights to the new function zonefs_inode_update_mode(). Furthermore, since on mount an inode wpoffset is always zero when zonefs_check_zone_condition() is called during an inode initialization, the "mount" boolean argument is not necessary for the readonly zone case. This argument is thus removed. zonefs_io_error_cb() is also modified to use the inode offline and zone state flags instead of checking the device zone condition. The multiple calls to zonefs_check_zone_condition() are reduced to the first call on entry, which allows removing the "warn" argument. zonefs_inode_update_mode() is also used to update an inode access rights as zonefs_io_error_cb() modifies the inode flags depending on the volume error handling mode (defined with a mount option). Since an inode mode change differs for read-only zones between mount time and IO error time, the flag ZONEFS_ZONE_INIT_MODE is used to differentiate both cases. Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn

zonefs: Reorganize code

2023-01-23T00:25:50+00:00

Move all code related to zone file operations from super.c to the new file.c file. Inode and zone management code remains in super.c. Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn

quota: port to mnt_idmap

2023-01-19T08:24:29+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 inode_init_owner() to mnt_idmap

2023-01-19T08:24:28+00:00