This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / mm / shmem.c

diff --git a/mm/shmem.c b/mm/shmem.c
index 74596a4..f0e5fc7 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -46,6 +46,7 @@
 #include <asm/pgtable.h>
 
 /* This magic number is used in glibc for posix shared memory */
+#define TMPFS_MAGIC    0x01021994
 
 #define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long))
 #define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)
@@ -1120,9 +1121,15 @@ static int shmem_populate(struct vm_area_struct *vma,
                                return err;
                        }
                } else if (nonblock) {
-                       err = install_file_pte(mm, vma, addr, pgoff, prot);
-                       if (err)
-                               return err;
+                       /*
+                        * If a nonlinear mapping then store the file page
+                        * offset in the pte.
+                        */
+                       if (pgoff != linear_page_index(vma, addr)) {
+                               err = install_file_pte(mm, vma, addr, pgoff, prot);
+                               if (err)
+                                       return err;
+                       }
                }
 
                len -= PAGE_SIZE;
@@ -1150,24 +1157,41 @@ shmem_get_policy(struct vm_area_struct *vma, unsigned long addr)
 }
 #endif
 
-int shmem_lock(struct file *file, int lock, struct user_struct *user)
+/* Protects current->user->locked_shm from concurrent access */
+static spinlock_t shmem_lock_user = SPIN_LOCK_UNLOCKED;
+
+int shmem_lock(struct file *file, int lock, struct user_struct * user)
 {
        struct inode *inode = file->f_dentry->d_inode;
        struct shmem_inode_info *info = SHMEM_I(inode);
+       unsigned long lock_limit, locked;
        int retval = -ENOMEM;
 
        spin_lock(&info->lock);
+       spin_lock(&shmem_lock_user);
        if (lock && !(info->flags & VM_LOCKED)) {
-               if (!user_shm_lock(inode->i_size, user))
+               locked = inode->i_size >> PAGE_SHIFT;
+               locked += user->locked_shm;
+               lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
+               lock_limit >>= PAGE_SHIFT;
+               if ((locked > lock_limit) && !capable(CAP_IPC_LOCK))
                        goto out_nomem;
-               info->flags |= VM_LOCKED;
+               /* for this branch user == current->user so it won't go away under us */
+               atomic_inc(&user->__count);
+               user->locked_shm = locked;
        }
        if (!lock && (info->flags & VM_LOCKED) && user) {
-               user_shm_unlock(inode->i_size, user);
-               info->flags &= ~VM_LOCKED;
+               locked = inode->i_size >> PAGE_SHIFT;
+               user->locked_shm -= locked;
+               free_uid(user);
        }
+       if (lock)
+               info->flags |= VM_LOCKED;
+       else
+               info->flags &= ~VM_LOCKED;
        retval = 0;
 out_nomem:
+       spin_unlock(&shmem_lock_user);
        spin_unlock(&info->lock);
        return retval;
 }
@@ -1507,7 +1531,7 @@ static int shmem_statfs(struct super_block *sb, struct kstatfs *buf)
 {
        struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
 
-       buf->f_type = TMPFS_SUPER_MAGIC;
+       buf->f_type = TMPFS_MAGIC;
        buf->f_bsize = PAGE_CACHE_SIZE;
        spin_lock(&sbinfo->stat_lock);
        buf->f_blocks = sbinfo->max_blocks;
@@ -1837,7 +1861,7 @@ static int shmem_fill_super(struct super_block *sb,
        sb->s_maxbytes = SHMEM_MAX_BYTES;
        sb->s_blocksize = PAGE_CACHE_SIZE;
        sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
-       sb->s_magic = TMPFS_SUPER_MAGIC;
+       sb->s_magic = TMPFS_MAGIC;
        sb->s_op = &shmem_ops;
        inode = shmem_get_inode(sb, S_IFDIR | mode, 0);
        if (!inode)