diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/f2fs.rst | 19 | ||||
| -rw-r--r-- | Documentation/filesystems/fsverity.rst | 76 | ||||
| -rw-r--r-- | Documentation/filesystems/locking.rst | 7 | ||||
| -rw-r--r-- | Documentation/filesystems/overlayfs.rst | 8 | ||||
| -rw-r--r-- | Documentation/filesystems/porting.rst | 18 | ||||
| -rw-r--r-- | Documentation/filesystems/seq_file.rst | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.rst | 24 |
7 files changed, 143 insertions, 15 deletions
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst index dae15c96e659..35ed01a5fbc9 100644 --- a/Documentation/filesystems/f2fs.rst +++ b/Documentation/filesystems/f2fs.rst @@ -179,7 +179,6 @@ fault_type=%d Support configuring fault injection type, should be FAULT_KVMALLOC 0x000000002 FAULT_PAGE_ALLOC 0x000000004 FAULT_PAGE_GET 0x000000008 - FAULT_ALLOC_BIO 0x000000010 FAULT_ALLOC_NID 0x000000020 FAULT_ORPHAN 0x000000040 FAULT_BLOCK 0x000000080 @@ -247,8 +246,24 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off checkpointing. Set to "enabl hide up to all remaining free space. The actual space that would be unusable can be viewed at /sys/fs/f2fs/<disk>/unusable This space is reclaimed once checkpoint=enable. +checkpoint_merge When checkpoint is enabled, this can be used to create a kernel + daemon and make it to merge concurrent checkpoint requests as + much as possible to eliminate redundant checkpoint issues. Plus, + we can eliminate the sluggish issue caused by slow checkpoint + operation when the checkpoint is done in a process context in + a cgroup having low i/o budget and cpu shares. To make this + do better, we set the default i/o priority of the kernel daemon + to "3", to give one higher priority than other kernel threads. + This is the same way to give a I/O priority to the jbd2 + journaling thread of ext4 filesystem. +nocheckpoint_merge Disable checkpoint merge feature. compress_algorithm=%s Control compress algorithm, currently f2fs supports "lzo", "lz4", "zstd" and "lzo-rle" algorithm. +compress_algorithm=%s:%d Control compress algorithm and its compress level, now, only + "lz4" and "zstd" support compress level config. + algorithm level range + lz4 3 - 16 + zstd 1 - 22 compress_log_size=%u Support configuring compress cluster size, the size will be 4KB * (1 << %u), 16KB is minimum size, also it's default size. @@ -831,7 +846,7 @@ This is the default option. f2fs does automatic compression in the writeback of compression enabled files. 2) compress_mode=user -This disables the automaic compression and gives the user discretion of choosing the +This disables the automatic compression and gives the user discretion of choosing the target file and the timing. The user can do manual compression/decompression on the compression enabled files using F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE ioctls like the below. diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst index e0204a23e997..1d831e3cbcb3 100644 --- a/Documentation/filesystems/fsverity.rst +++ b/Documentation/filesystems/fsverity.rst @@ -217,6 +217,82 @@ FS_IOC_MEASURE_VERITY can fail with the following errors: - ``EOVERFLOW``: the digest is longer than the specified ``digest_size`` bytes. Try providing a larger buffer. +FS_IOC_READ_VERITY_METADATA +--------------------------- + +The FS_IOC_READ_VERITY_METADATA ioctl reads verity metadata from a +verity file. This ioctl is available since Linux v5.12. + +This ioctl allows writing a server program that takes a verity file +and serves it to a client program, such that the client can do its own +fs-verity compatible verification of the file. This only makes sense +if the client doesn't trust the server and if the server needs to +provide the storage for the client. + +This is a fairly specialized use case, and most fs-verity users won't +need this ioctl. + +This ioctl takes in a pointer to the following structure:: + + #define FS_VERITY_METADATA_TYPE_MERKLE_TREE 1 + #define FS_VERITY_METADATA_TYPE_DESCRIPTOR 2 + #define FS_VERITY_METADATA_TYPE_SIGNATURE 3 + + struct fsverity_read_metadata_arg { + __u64 metadata_type; + __u64 offset; + __u64 length; + __u64 buf_ptr; + __u64 __reserved; + }; + +``metadata_type`` specifies the type of metadata to read: + +- ``FS_VERITY_METADATA_TYPE_MERKLE_TREE`` reads the blocks of the + Merkle tree. The blocks are returned in order from the root level + to the leaf level. Within each level, the blocks are returned in + the same order that their hashes are themselves hashed. + See `Merkle tree`_ for more information. + +- ``FS_VERITY_METADATA_TYPE_DESCRIPTOR`` reads the fs-verity + descriptor. See `fs-verity descriptor`_. + +- ``FS_VERITY_METADATA_TYPE_SIGNATURE`` reads the signature which was + passed to FS_IOC_ENABLE_VERITY, if any. See `Built-in signature + verification`_. + +The semantics are similar to those of ``pread()``. ``offset`` +specifies the offset in bytes into the metadata item to read from, and +``length`` specifies the maximum number of bytes to read from the +metadata item. ``buf_ptr`` is the pointer to the buffer to read into, +cast to a 64-bit integer. ``__reserved`` must be 0. On success, the +number of bytes read is returned. 0 is returned at the end of the +metadata item. The returned length may be less than ``length``, for +example if the ioctl is interrupted. + +The metadata returned by FS_IOC_READ_VERITY_METADATA isn't guaranteed +to be authenticated against the file digest that would be returned by +`FS_IOC_MEASURE_VERITY`_, as the metadata is expected to be used to +implement fs-verity compatible verification anyway (though absent a +malicious disk, the metadata will indeed match). E.g. to implement +this ioctl, the filesystem is allowed to just read the Merkle tree +blocks from disk without actually verifying the path to the root node. + +FS_IOC_READ_VERITY_METADATA can fail with the following errors: + +- ``EFAULT``: the caller provided inaccessible memory +- ``EINTR``: the ioctl was interrupted before any data was read +- ``EINVAL``: reserved fields were set, or ``offset + length`` + overflowed +- ``ENODATA``: the file is not a verity file, or + FS_VERITY_METADATA_TYPE_SIGNATURE was requested but the file doesn't + have a built-in signature +- ``ENOTTY``: this type of filesystem does not implement fs-verity, or + this ioctl is not yet implemented on it +- ``EOPNOTSUPP``: the kernel was not configured with fs-verity + support, or the filesystem superblock has not had the 'verity' + feature enabled on it. (See `Filesystem support`_.) + FS_IOC_GETFLAGS --------------- diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index c0f2c7586531..b7dcc86c92a4 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -126,9 +126,10 @@ prototypes:: int (*get)(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size); - int (*set)(const struct xattr_handler *handler, struct dentry *dentry, - struct inode *inode, const char *name, const void *buffer, - size_t size, int flags); + int (*set)(const struct xattr_handler *handler, + struct user_namespace *mnt_userns, + struct dentry *dentry, struct inode *inode, const char *name, + const void *buffer, size_t size, int flags); locking rules: all may block diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index 587a93973929..78240e29b0bb 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -586,6 +586,14 @@ without significant effort. The advantage of mounting with the "volatile" option is that all forms of sync calls to the upper filesystem are omitted. +In order to avoid a giving a false sense of safety, the syncfs (and fsync) +semantics of volatile mounts are slightly different than that of the rest of +VFS. If any writeback error occurs on the upperdir's filesystem after a +volatile mount takes place, all sync functions will return an error. Once this +condition is reached, the filesystem will not recover, and every subsequent sync +call will return an error, even if the upperdir has not experience a new error +since the last sync call. + When overlay is mounted with "volatile" option, the directory "$workdir/work/incompat/volatile" is created. During next mount, overlay checks for this directory and refuses to mount if present. This is a strong diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 867036aa90b8..633610253f45 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -717,6 +717,8 @@ be removed. Switch while you still can; the old one won't stay. **mandatory** ->setxattr() and xattr_handler.set() get dentry and inode passed separately. +The xattr_handler.set() gets passed the user namespace of the mount the inode +is seen from so filesystems can idmap the i_uid and i_gid accordingly. dentry might be yet to be attached to inode, so do _not_ use its ->d_inode in the instances. Rationale: !@#!@# security_d_instantiate() needs to be called before we attach dentry to inode and !@#!@##!@$!$#!@#$!@$!@$ smack @@ -865,3 +867,19 @@ no matter what. Everything is handled by the caller. clone_private_mount() returns a longterm mount now, so the proper destructor of its result is kern_unmount() or kern_unmount_array(). + +--- + +**mandatory** + +zero-length bvec segments are disallowed, they must be filtered out before +passed on to an iterator. + +--- + +**mandatory** + +For bvec based itererators bio_iov_iter_get_pages() now doesn't copy bvecs but +uses the one provided. Anyone issuing kiocb-I/O should ensure that the bvec and +page references stay until I/O has completed, i.e. until ->ki_complete() has +been called or returned with non -EIOCBQUEUED code. diff --git a/Documentation/filesystems/seq_file.rst b/Documentation/filesystems/seq_file.rst index 56856481dc8d..a6726082a7c2 100644 --- a/Documentation/filesystems/seq_file.rst +++ b/Documentation/filesystems/seq_file.rst @@ -217,6 +217,12 @@ between the calls to start() and stop(), so holding a lock during that time is a reasonable thing to do. The seq_file code will also avoid taking any other locks while the iterator is active. +The iterater value returned by start() or next() is guaranteed to be +passed to a subsequent next() or stop() call. This allows resources +such as locks that were taken to be reliably released. There is *no* +guarantee that the iterator will be passed to show(), though in practice +it often will be. + Formatted output ================ diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index 18d69a4559d6..2049bbf5e388 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -270,7 +270,10 @@ or bottom half). ->alloc_inode. ``dirty_inode`` - this method is called by the VFS to mark an inode dirty. + this method is called by the VFS when an inode is marked dirty. + This is specifically for the inode itself being marked dirty, + not its data. If the update needs to be persisted by fdatasync(), + then I_DIRTY_DATASYNC will be set in the flags argument. ``write_inode`` this method is called when the VFS needs to write an inode to @@ -415,28 +418,29 @@ As of kernel 2.6.22, the following members are defined: .. code-block:: c struct inode_operations { - int (*create) (struct inode *,struct dentry *, umode_t, bool); + int (*create) (struct user_namespace *, struct inode *,struct dentry *, umode_t, bool); struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); int (*link) (struct dentry *,struct inode *,struct dentry *); int (*unlink) (struct inode *,struct dentry *); - int (*symlink) (struct inode *,struct dentry *,const char *); - int (*mkdir) (struct inode *,struct dentry *,umode_t); + int (*symlink) (struct user_namespace *, struct inode *,struct dentry *,const char *); + int (*mkdir) (struct user_namespace *, struct inode *,struct dentry *,umode_t); int (*rmdir) (struct inode *,struct dentry *); - int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t); - int (*rename) (struct inode *, struct dentry *, + int (*mknod) (struct user_namespace *, struct inode *,struct dentry *,umode_t,dev_t); + int (*rename) (struct user_namespace *, struct inode *, struct dentry *, struct inode *, struct dentry *, unsigned int); int (*readlink) (struct dentry *, char __user *,int); const char *(*get_link) (struct dentry *, struct inode *, struct delayed_call *); - int (*permission) (struct inode *, int); + int (*permission) (struct user_namespace *, struct inode *, int); int (*get_acl)(struct inode *, int); - int (*setattr) (struct dentry *, struct iattr *); - int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); + int (*setattr) (struct user_namespace *, struct dentry *, struct iattr *); + int (*getattr) (struct user_namespace *, const struct path *, struct kstat *, u32, unsigned int); ssize_t (*listxattr) (struct dentry *, char *, size_t); void (*update_time)(struct inode *, struct timespec *, int); int (*atomic_open)(struct inode *, struct dentry *, struct file *, unsigned open_flag, umode_t create_mode); - int (*tmpfile) (struct inode *, struct dentry *, umode_t); + int (*tmpfile) (struct user_namespace *, struct inode *, struct dentry *, umode_t); + int (*set_acl)(struct user_namespace *, struct inode *, struct posix_acl *, int); }; Again, all methods are called without any locks being held, unless |