user/sven/linux.git/Documentation/filesystems, branch v4.11.3

Documentation/filesystems: fix documentation for ->getattr()

2017-04-03T05:05:56Z

Following the recent merge of statx, correct the documented prototype for the ->getattr() inode operation, and add an entry to the porting file. Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Al Viro

statx: Add a system call to make enhanced file info available

2017-03-03T01:51:15Z

Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells Signed-off-by: Al Viro

Merge tag 'for-f2fs-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2017-03-01T23:55:04Z

Pull f2fs updates from Jaegeuk Kim: "This round introduces several interesting features such as on-disk NAT bitmaps, IO alignment, and a discard thread. And it includes a couple of major bug fixes as below. Enhancements: - introduce on-disk bitmaps to avoid scanning NAT blocks when getting free nids - support IO alignment to prepare open-channel SSD integration in future - introduce a discard thread to avoid long latency during checkpoint and fstrim - use SSR for warm node and enable inline_xattr by default - introduce in-memory bitmaps to check FS consistency for debugging - improve write_begin by avoiding needless read IO Bug fixes: - fix broken zone_reset behavior for SMR drive - fix wrong victim selection policy during GC - fix missing behavior when preparing discard commands - fix bugs in atomic write support and fiemap - workaround to handle multiple f2fs_add_link calls having same name ... and it includes a bunch of clean-up patches as well" * tag 'for-f2fs-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (97 commits) f2fs: avoid to flush nat journal entries f2fs: avoid to issue redundant discard commands f2fs: fix a plint compile warning f2fs: add f2fs_drop_inode tracepoint f2fs: Fix zoned block device support f2fs: remove redundant set_page_dirty() f2fs: fix to enlarge size of write_io_dummy mempool f2fs: fix memory leak of write_io_dummy mempool during umount f2fs: fix to update F2FS_{CP_}WB_DATA count correctly f2fs: use MAX_FREE_NIDS for the free nids target f2fs: introduce free nid bitmap f2fs: new helper cur_cp_crc() getting crc in f2fs_checkpoint f2fs: update the comment of default nr_pages to skipping f2fs: drop the duplicate pval in f2fs_getxattr f2fs: Don't update the xattr data that same as the exist f2fs: kill __is_extent_same f2fs: avoid bggc->fggc when enough free segments are avaliable after cp f2fs: select target segment with closer temperature in SSR mode f2fs: show simple call stack in fault injection message f2fs: no need lock_op in f2fs_write_inline_data ...

Merge tag 'ceph-for-4.11-rc1' of git://github.com/ceph/ceph-client

2017-02-28T23:36:09Z

Pull ceph updates from Ilya Dryomov: "This time around we have: - support for rbd data-pool feature, which enables rbd images on erasure-coded pools (myself). CEPH_PG_MAX_SIZE has been bumped to allow erasure-coded profiles with k+m up to 32. - a patch for ceph_d_revalidate() performance regression introduced in 4.9, along with some cleanups in the area (Jeff Layton) - a set of fixes for unsafe ->d_parent accesses in CephFS (Jeff Layton) - buffered reads are now processed in rsize windows instead of rasize windows (Andreas Gerstmayr). The new default for rsize mount option is 64M. - ack vs commit distinction is gone, greatly simplifying ->fsync() and MOSDOpReply handling code (myself) ... also a few filesystem bug fixes from Zheng, a CRUSH sync up (CRUSH computations are still serialized though) and several minor fixes and cleanups all over" * tag 'ceph-for-4.11-rc1' of git://github.com/ceph/ceph-client: (52 commits) libceph, rbd, ceph: WRITE | ONDISK -> WRITE libceph: get rid of ack vs commit ceph: remove special ack vs commit behavior ceph: tidy some white space in get_nonsnap_parent() crush: fix dprintk compilation crush: do is_out test only if we do not collide ceph: remove req from unsafe list when unregistering it rbd: constify device_type structure rbd: kill obj_request->object_name and rbd_segment_name_cache rbd: store and use obj_request->object_no rbd: RBD_V{1,2}_DATA_FORMAT macros rbd: factor out __rbd_osd_req_create() rbd: set offset and length outside of rbd_obj_request_create() rbd: support for data-pool feature rbd: introduce rbd_init_layout() rbd: use rbd_obj_bytes() more rbd: remove now unused rbd_obj_request_wait() and helpers rbd: switch rbd_obj_method_sync() to ceph_osdc_call() libceph: pass reply buffer length through ceph_osdc_call() rbd: do away with obj_request in rbd_obj_read_sync() ...

scripts/spelling.txt: add "an user" pattern and fix typo instances

2017-02-28T02:43:46Z

Fix typos and add the following to the scripts/spelling.txt: an user||a user an userspace||a userspace I also added "userspace" to the list since it is a common word in Linux. I found some instances for "an userfaultfd", but I did not add it to the list. I felt it is endless to find words that start with "user" such as "userland" etc., so must draw a line somewhere. Link: http://lkml.kernel.org/r/1481573103-11329-4-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

autofs: update ioctl documentation regarding struct autofs_dev_ioctl

2017-02-28T02:43:45Z

This is the same as bf72eda5 except that it's a different file. Sync documentation with changes made by 730c9eec in 2009. Link: http://lkml.kernel.org/r/148577165630.9801.6081791213151121657.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi Signed-off-by: Ian Kent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

autofs: fix wrong ioctl documentation regarding devid

2017-02-28T02:43:45Z

This is the same as d8732841 except that it's a different file. A caller has no devid input, and devid is obtained via superblock. Link: http://lkml.kernel.org/r/148577165119.9801.16967562019122274820.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi Signed-off-by: Ian Kent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

autofs: fix typo in Documentation

2017-02-28T02:43:45Z

Link: http://lkml.kernel.org/r/148577164606.9801.12571810310561599401.stgit@pluto.themaw.net Signed-off-by: Tomohiro Kusumi Signed-off-by: Ian Kent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

f2fs: introduce noinline_xattr mount option

2017-02-23T18:21:48Z

This patch introduces new mount option 'noinline_xattr', so we can disable inline xattr functionality which is already set as a default mount option. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix a typo in f2fs.txt

2017-02-23T18:10:49Z

There is a typo "f2f2" in f2fs.txt, this patch fixes it. Signed-off-by: Tiezhu Yang Signed-off-by: Jaegeuk Kim