fs/sysv: Replace kmap() with kmap_local_page()

[linux-2.6-microblaze.git] / fs / sysv / dir.c

diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index 6b402e6..3ed98d6 100644 (file)
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -28,9 +28,9 @@ const struct file_operations sysv_dir_operations = {
        .fsync          = generic_file_fsync,
 };
 
-inline void dir_put_page(struct page *page)
+inline void dir_put_page(struct page *page, void *page_addr)
 {
-       kunmap(page);
+       kunmap_local((void *)((unsigned long)page_addr & PAGE_MASK));
        put_page(page);
 }
 
@@ -57,15 +57,21 @@ static int sysv_handle_dirsync(struct inode *dir)
        return err;
 }
 
+/*
+ * Calls to dir_get_page()/dir_put_page() must be nested according to the
+ * rules documented in mm/highmem.rst.
+ *
+ * NOTE: sysv_find_entry() and sysv_dotdot() act as calls to dir_get_page()
+ * and must be treated accordingly for nesting purposes.
+ */
 static void *dir_get_page(struct inode *dir, unsigned long n, struct page **p)
 {
        struct address_space *mapping = dir->i_mapping;
        struct page *page = read_mapping_page(mapping, n, NULL);
        if (IS_ERR(page))
                return ERR_CAST(page);
-       kmap(page);
        *p = page;
-       return page_address(page);
+       return kmap_local_page(page);
 }
 
 static int sysv_readdir(struct file *file, struct dir_context *ctx)
@@ -103,11 +109,11 @@ static int sysv_readdir(struct file *file, struct dir_context *ctx)
                        if (!dir_emit(ctx, name, strnlen(name,SYSV_NAMELEN),
                                        fs16_to_cpu(SYSV_SB(sb), de->inode),
                                        DT_UNKNOWN)) {
-                               dir_put_page(page);
+                               dir_put_page(page, kaddr);
                                return 0;
                        }
                }
-               dir_put_page(page);
+               dir_put_page(page, kaddr);
        }
        return 0;
 }
@@ -130,6 +136,11 @@ static inline int namecompare(int len, int maxlen,
  * returns the cache buffer in which the entry was found, and the entry
  * itself (as a parameter - res_dir). It does NOT read the inode of the
  * entry - you'll have to do that yourself if you want to.
+ *
+ * On Success dir_put_page() should be called on *res_page.
+ *
+ * sysv_find_entry() acts as a call to dir_get_page() and must be treated
+ * accordingly for nesting purposes.
  */
 struct sysv_dir_entry *sysv_find_entry(struct dentry *dentry, struct page **res_page)
 {
@@ -161,7 +172,7 @@ struct sysv_dir_entry *sysv_find_entry(struct dentry *dentry, struct page **res_
                                                        name, de->name))
                                        goto found;
                        }
-                       dir_put_page(page);
+                       dir_put_page(page, kaddr);
                }
 
                if (++n >= npages)
@@ -204,7 +215,7 @@ int sysv_add_link(struct dentry *dentry, struct inode *inode)
                                goto out_page;
                        de++;
                }
-               dir_put_page(page);
+               dir_put_page(page, kaddr);
        }
        BUG();
        return -EINVAL;
@@ -223,7 +234,7 @@ got_it:
        mark_inode_dirty(dir);
        err = sysv_handle_dirsync(dir);
 out_page:
-       dir_put_page(page);
+       dir_put_page(page, kaddr);
        return err;
 out_unlock:
        unlock_page(page);
@@ -241,7 +252,7 @@ int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
        BUG_ON(err);
        de->inode = 0;
        dir_commit_chunk(page, pos, SYSV_DIRSIZE);
-       dir_put_page(page);
+       dir_put_page(page, de);
        inode->i_ctime = inode->i_mtime = current_time(inode);
        mark_inode_dirty(inode);
        return sysv_handle_dirsync(inode);
@@ -261,9 +272,7 @@ int sysv_make_empty(struct inode *inode, struct inode *dir)
                unlock_page(page);
                goto fail;
        }
-       kmap(page);
-
-       base = (char*)page_address(page);
+       base = kmap_local_page(page);
        memset(base, 0, PAGE_SIZE);
 
        de = (struct sysv_dir_entry *) base;
@@ -273,7 +282,7 @@ int sysv_make_empty(struct inode *inode, struct inode *dir)
        de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), dir->i_ino);
        strcpy(de->name,"..");
 
-       kunmap(page);
+       kunmap_local(base);
        dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
        err = sysv_handle_dirsync(inode);
 fail:
@@ -289,10 +298,10 @@ int sysv_empty_dir(struct inode * inode)
        struct super_block *sb = inode->i_sb;
        struct page *page = NULL;
        unsigned long i, npages = dir_pages(inode);
+       char *kaddr;
 
        for (i = 0; i < npages; i++) {
-               char *kaddr;
-               struct sysv_dir_entry * de;
+               struct sysv_dir_entry *de;
 
                kaddr = dir_get_page(inode, i, &page);
                if (IS_ERR(kaddr))
@@ -316,12 +325,12 @@ int sysv_empty_dir(struct inode * inode)
                        if (de->name[1] != '.' || de->name[2])
                                goto not_empty;
                }
-               dir_put_page(page);
+               dir_put_page(page, kaddr);
        }
        return 1;
 
 not_empty:
-       dir_put_page(page);
+       dir_put_page(page, kaddr);
        return 0;
 }
 
@@ -338,12 +347,19 @@ void sysv_set_link(struct sysv_dir_entry *de, struct page *page,
        BUG_ON(err);
        de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
        dir_commit_chunk(page, pos, SYSV_DIRSIZE);
-       dir_put_page(page);
+       dir_put_page(page, de);
        dir->i_mtime = dir->i_ctime = current_time(dir);
        mark_inode_dirty(dir);
        sysv_handle_dirsync(inode);
 }
 
+/*
+ * Calls to dir_get_page()/dir_put_page() must be nested according to the
+ * rules documented in mm/highmem.rst.
+ *
+ * sysv_dotdot() acts as a call to dir_get_page() and must be treated
+ * accordingly for nesting purposes.
+ */
 struct sysv_dir_entry *sysv_dotdot(struct inode *dir, struct page **p)
 {
        struct sysv_dir_entry *de = dir_get_page(dir, 0, p);
@@ -362,7 +378,7 @@ ino_t sysv_inode_by_name(struct dentry *dentry)
        
        if (de) {
                res = fs16_to_cpu(SYSV_SB(dentry->d_sb), de->inode);
-               dir_put_page(page);
+               dir_put_page(page, de);
        }
        return res;
 }