From 9d66586f7723b73c5925c7c7819c260484627851 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 16 Jun 2007 10:16:16 -0700 Subject: [PATCH] shm: fix the filename of hugetlb sysv shared memory Some user space tools need to identify SYSV shared memory when examining /proc//maps. To do so they look for a block device with major zero, a dentry named SYSV, and having the minor of the internal sysv shared memory kernel mount. To help these tools and to make it easier for people just browsing /proc//maps this patch modifies hugetlb sysv shared memory to use the SYSV dentry naming convention. User space tools will still have to be aware that hugetlb sysv shared memory lives on a different internal kernel mount and so has a different block device minor number from the rest of sysv shared memory. Signed-off-by: Eric W. Biederman Cc: "Serge E. Hallyn" Cc: Albert Cahalan Cc: Badari Pulavarty Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 7 ++----- include/linux/hugetlb.h | 4 ++-- ipc/shm.c | 6 +++--- 3 files changed, 7 insertions(+), 10 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index aa083dd..e6b46b3 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -736,15 +736,13 @@ static int can_do_hugetlb_shm(void) can_do_mlock()); } -struct file *hugetlb_zero_setup(size_t size) +struct file *hugetlb_file_setup(const char *name, size_t size) { int error = -ENOMEM; struct file *file; struct inode *inode; struct dentry *dentry, *root; struct qstr quick_string; - char buf[16]; - static atomic_t counter; if (!hugetlbfs_vfsmount) return ERR_PTR(-ENOENT); @@ -756,8 +754,7 @@ struct file *hugetlb_zero_setup(size_t size) return ERR_PTR(-ENOMEM); root = hugetlbfs_vfsmount->mnt_root; - snprintf(buf, 16, "%u", atomic_inc_return(&counter)); - quick_string.name = buf; + quick_string.name = name; quick_string.len = strlen(quick_string.name); quick_string.hash = 0; dentry = d_alloc(root, &quick_string); diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index b4570b6..2c13715 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -163,7 +163,7 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb) extern const struct file_operations hugetlbfs_file_operations; extern struct vm_operations_struct hugetlb_vm_ops; -struct file *hugetlb_zero_setup(size_t); +struct file *hugetlb_file_setup(const char *name, size_t); int hugetlb_get_quota(struct address_space *mapping); void hugetlb_put_quota(struct address_space *mapping); @@ -185,7 +185,7 @@ static inline void set_file_hugepages(struct file *file) #define is_file_hugepages(file) 0 #define set_file_hugepages(file) BUG() -#define hugetlb_zero_setup(size) ERR_PTR(-ENOSYS) +#define hugetlb_file_setup(name,size) ERR_PTR(-ENOSYS) #endif /* !CONFIG_HUGETLBFS */ diff --git a/ipc/shm.c b/ipc/shm.c index 047b823..0852f20 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -366,9 +366,10 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size) return error; } + sprintf (name, "SYSV%08x", key); if (shmflg & SHM_HUGETLB) { - /* hugetlb_zero_setup takes care of mlock user accounting */ - file = hugetlb_zero_setup(size); + /* hugetlb_file_setup takes care of mlock user accounting */ + file = hugetlb_file_setup(name, size); shp->mlock_user = current->user; } else { int acctflag = VM_ACCOUNT; @@ -379,7 +380,6 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size) if ((shmflg & SHM_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER) acctflag = 0; - sprintf (name, "SYSV%08x", key); file = shmem_file_setup(name, size, acctflag); } error = PTR_ERR(file); -- 1.8.2.3