lwn.git/fs/hostfs/hostfs_user.c, branch docs-6.10

hostfs: Fix ephemeral inodes

2023-06-12T19:26:19+00:00

hostfs creates a new inode for each opened or created file, which created useless inode allocations and forbade identifying a host file with a kernel inode. Fix this uncommon filesystem behavior by tying kernel inodes to host file's inode and device IDs. Even if the host filesystem inodes may be recycled, this cannot happen while a file referencing it is opened, which is the case with hostfs. It should be noted that hostfs inode IDs may not be unique for the same hostfs superblock because multiple host's (backed) superblocks may be used. Delete inodes when dropping them to force backed host's file descriptors closing. This enables to entirely remove ARCH_EPHEMERAL_INODES, and then makes Landlock fully supported by UML. This is very useful for testing changes. These changes also factor out and simplify some helpers thanks to the new hostfs_inode_update() and the hostfs_iget() revamp: read_name(), hostfs_create(), hostfs_lookup(), hostfs_mknod(), and hostfs_fill_sb_common(). A following commit with new Landlock tests check this new hostfs inode consistency. Cc: Anton Ivanov Cc: Johannes Berg Acked-by: Richard Weinberger Link: https://lore.kernel.org/r/20230612191430.339153-2-mic@digikod.net Signed-off-by: Mickaël Salaün

hostfs: rename do_rmdir() to hostfs_do_rmdir()

2018-04-02T18:15:53+00:00

do_rmdir() is used in the VFS layer at fs/namei.c, so use a different name in hostfs. Cc: Jeff Dike Cc: user-mode-linux-devel@lists.sourceforge.net Acked-by: Richard Weinberger Signed-off-by: Dominik Brodowski

um: hostfs: Reduce number of syscalls in readdir

2015-04-13T19:01:07+00:00

Currently hostfs issues every time a seekdir(), in fact it has to do this only upon the first call. Also telldir() can be omitted as we can obtain the directory offset from readdir(). Signed-off-by: Richard Weinberger

hostfs: No need to box and later unbox the file mode

2015-03-26T22:27:53+00:00

There is really no point in having a function with 10 arguments. Reported-by: Daniel Walter Signed-off-by: Richard Weinberger

hostfs: support rename flags

2014-08-07T18:40:09+00:00

Support RENAME_NOREPLACE and RENAME_EXCHANGE flags on hostfs if the underlying filesystem supports it. Since renameat2(2) is not yet in any libc, use syscall(2) to invoke the renameat2 syscall. Signed-off-by: Miklos Szeredi Cc: Richard Weinberger Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

um: get rid of pointless include "..." where include <...> will do

2012-10-09T20:28:45+00:00

Signed-off-by: Al Viro Signed-off-by: Richard Weinberger

uml/hostfs: Propagate dirent.d_type to filldir()

2012-03-24T23:29:52+00:00

Currently the (optional) d_type member in struct dirent is always DT_UNKNOWN on hostfs, which may confuse buggy software using readdir(). Make sure to propagate its value from the underlying filesystem if it's available there. Signed-off-by: Geert Uytterhoeven Signed-off-by: Richard Weinberger

um: kill useless include of user.h

2011-11-02T13:15:13+00:00

everything in USER_OBJ gets it via -include user.h Signed-off-by: Al Viro Signed-off-by: Richard Weinberger

hostfs: code cleanups

2010-10-26T23:52:12+00:00

Some code cleanups for hostfs. Signed-off-by: Richard Weinberger Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

hostfs: fix UML crash: remove f_spare from hostfs

2010-10-26T23:52:04+00:00

365b1818 ("add f_flags to struct statfs(64)") resized f_spare within struct statfs which caused a UML crash. There is no need to copy f_spare. Signed-off-by: Richard Weinberger Reported-by: Toralf Förster Tested-by: Toralf Förster Cc: Christoph Hellwig Cc: Al Viro Cc: Jeff Dike Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds