From 516dffdcd8827a40532798602830dfcfc672294c Mon Sep 17 00:00:00 2001 From: Adam Litke Date: Thu, 1 Mar 2007 15:46:08 -0800 Subject: [PATCH] [PATCH] Fix get_unmapped_area and fsync for hugetlb shm segments This patch provides the following hugetlb-related fixes to the recent stacked shm files changes: - Update is_file_hugepages() so it will reconize hugetlb shm segments. - get_unmapped_area must be called with the nested file struct to handle the sfd->file->f_ops->get_unmapped_area == NULL case. - The fsync f_op must be wrapped since it is specified in the hugetlbfs f_ops. This is based on proposed fixes from Eric Biederman that were debugged and tested by me. Without it, attempting to use hugetlb shared memory segments on powerpc (and likely ia64) will kill your box. Signed-off-by: Adam Litke Cc: Eric Biederman Cc: Andrew Morton Acked-by: William Irwin Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 8 +++++++- include/linux/shm.h | 5 +++++ ipc/shm.c | 32 ++++++++++++++++++++++++++------ 3 files changed, 38 insertions(+), 7 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index a60995afe3..3f3e7a648d 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -4,6 +4,7 @@ #ifdef CONFIG_HUGETLB_PAGE #include +#include #include struct ctl_table; @@ -168,7 +169,12 @@ void hugetlb_put_quota(struct address_space *mapping); static inline int is_file_hugepages(struct file *file) { - return file->f_op == &hugetlbfs_file_operations; + if (file->f_op == &hugetlbfs_file_operations) + return 1; + if (is_file_shm_hugepages(file)) + return 1; + + return 0; } static inline void set_file_hugepages(struct file *file) diff --git a/include/linux/shm.h b/include/linux/shm.h index a2c896ad0b..ad2e3af659 100644 --- a/include/linux/shm.h +++ b/include/linux/shm.h @@ -96,12 +96,17 @@ struct shmid_kernel /* private to the kernel */ #ifdef CONFIG_SYSVIPC long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr); +extern int is_file_shm_hugepages(struct file *file); #else static inline long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr) { return -ENOSYS; } +static inline int is_file_shm_hugepages(struct file *file) +{ + return 0; +} #endif #endif /* __KERNEL__ */ diff --git a/ipc/shm.c b/ipc/shm.c index 3d0eb7940e..4fefbad709 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -285,21 +285,41 @@ static int shm_release(struct inode *ino, struct file *file) return 0; } -#ifndef CONFIG_MMU +static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + int (*fsync) (struct file *, struct dentry *, int datasync); + struct shm_file_data *sfd = shm_file_data(file); + int ret = -EINVAL; + + fsync = sfd->file->f_op->fsync; + if (fsync) + ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); + return ret; +} + static unsigned long shm_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct shm_file_data *sfd = shm_file_data(file); - return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, pgoff, - flags); + return get_unmapped_area(sfd->file, addr, len, pgoff, flags); +} + +int is_file_shm_hugepages(struct file *file) +{ + int ret = 0; + + if (file->f_op == &shm_file_operations) { + struct shm_file_data *sfd; + sfd = shm_file_data(file); + ret = is_file_hugepages(sfd->file); + } + return ret; } -#else -#define shm_get_unmapped_area NULL -#endif static const struct file_operations shm_file_operations = { .mmap = shm_mmap, + .fsync = shm_fsync, .release = shm_release, .get_unmapped_area = shm_get_unmapped_area, }; -- 2.39.5