torvalds/linux
3
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-03-22 07:27:12 +08:00
Code Issues Packages Projects Releases Wiki Activity

memfd: export alloc_file()

Browse Source 
Patch series "mm: memfd_luo hotfixes".

This series contains a couple of fixes for memfd preservation using LUO.


This patch (of 3):

The Live Update Orchestrator's (LUO) memfd preservation works by
preserving all the folios of a memfd, re-creating an empty memfd on the
next boot, and then inserting back the preserved folios.

Currently it creates the file by directly calling shmem_file_setup(). 
This leaves out other work done by alloc_file() like setting up the file
mode, flags, or calling the security hooks.

Export alloc_file() to let memfd_luo use it.  Rename it to
memfd_alloc_file() since it is no longer private and thus needs a
subsystem prefix.

Link: https://lkml.kernel.org/r/20260122151842.4069702-1-pratyush@kernel.org
Link: https://lkml.kernel.org/r/20260122151842.4069702-2-pratyush@kernel.org
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Pratyush Yadav (Google)
2026-01-22 16:18:39 +01:00
committed by Andrew Morton
parent dd9e2f5b38
commit 71e2b5eadb
2 changed files with 8 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/memfd.h
View File

@@ -17,6 +17,7 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx);
* to by vm_flags_ptr.
*/
int memfd_check_seals_mmap(struct file *file, vm_flags_t *vm_flags_ptr);
struct file *memfd_alloc_file(const char *name, unsigned int flags);
#else
static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a)
{
@@ -31,6 +32,11 @@ static inline int memfd_check_seals_mmap(struct file *file,
{
return 0;
}
static inline struct file *memfd_alloc_file(const char *name, unsigned int flags)
{
return ERR_PTR(-EINVAL);
}
#endif
#endif /* __LINUX_MEMFD_H */

4
mm/memfd.c
View File

@@ -456,7 +456,7 @@ err_name:
return ERR_PTR(error);
}
static struct file *alloc_file(const char *name, unsigned int flags)
struct file *memfd_alloc_file(const char *name, unsigned int flags)
{
unsigned int *file_seals;
struct file *file;
@@ -520,5 +520,5 @@ SYSCALL_DEFINE2(memfd_create,
return PTR_ERR(name);
fd_flags = (flags & MFD_CLOEXEC) ? O_CLOEXEC : 0;
return FD_ADD(fd_flags, alloc_file(name, flags));
return FD_ADD(fd_flags, memfd_alloc_file(name, flags));
}