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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-16 17:23:55 +08:00
linux-next/fs/kernfs
Tejun Heo f601f9a2bf kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()
kernfs_unmap_bin_file() is supposed to unmap all memory mappings of
the target file before kernfs_remove() finishes; however, it currently
is being called from kernfs_addrm_finish() and has the same race
problem as the original implementation of deactivation when there are
multiple removers - only the remover which snatches the node to its
addrm_cxt->removed list is guaranteed to wait for its completion
before returning.

It can be fixed by moving kernfs_unmap_bin_file() invocation from
kernfs_addrm_finish() to __kernfs_remove().  The function may be
called multiple times but that shouldn't do any harm.

We end up dropping kernfs_mutex in the removal loop and the node may
be removed inbetween by someone else.  kernfs_unlink_sibling() is
updated to test whether the node has already been removed and return
accordingly.  __kernfs_remove() in turn performs post-unlinking
cleanup only if it actually unlinked the node.

KERNFS_HAS_MMAP test is moved out of the unmap function into
__kernfs_remove() so that we don't unlock kernfs_mutex unnecessarily.
While at it, drop the now meaningless "bin" qualifier from the
function name.

v2: Rewritten to fit the v2 restructuring of removal path.  HAS_MMAP
    test relocated.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10 13:48:08 -08:00
..
dir.c kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove() 2014-01-10 13:48:08 -08:00
file.c kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove() 2014-01-10 13:48:08 -08:00
inode.c kernfs: s/sysfs/kernfs/ in internal functions and whatever is left 2013-12-11 17:39:20 -08:00
kernfs-internal.h kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove() 2014-01-10 13:48:08 -08:00
Makefile sysfs, kernfs: add skeletons for kernfs 2013-11-27 13:28:24 -08:00
mount.c kernfs: s/sysfs/kernfs/ in internal functions and whatever is left 2013-12-11 17:39:20 -08:00
symlink.c kernfs: remove KERNFS_REMOVED 2014-01-10 13:44:25 -08:00