minixfs: change the signature of dir_get_page()

Change the signature of dir_get_page() in order to prepare this function
to the conversion to the use of kmap_local_page(). Change also those call
sites which are required to adjust to the new signature.

Essentially a copy of the corresponding fs/sysv commit by
Fabio M. De Francesco <fmdefrancesco@gmail.com>

Reviewed-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index 34a5d17f0796b2708b14245c710199e6ed94b9ea..4e5483adea401a57cc6872e45c267a5be7cdd3e7 100644 (file)
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -70,13 +70,15 @@ static int minix_handle_dirsync(struct inode *dir)
        return err;
 }
 
-static struct page * dir_get_page(struct inode *dir, unsigned long n)
+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))
-               kmap(page);
-       return page;
+       if (IS_ERR(page))
+               return ERR_CAST(page);
+       kmap(page);
+       *p = page;
+       return page_address(page);
 }
 
 static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
@@ -104,11 +106,11 @@ static int minix_readdir(struct file *file, struct dir_context *ctx)
 
        for ( ; n < npages; n++, offset = 0) {
                char *p, *kaddr, *limit;
-               struct page *page = dir_get_page(inode, n);
+               struct page *page;
 
-               if (IS_ERR(page))
+               kaddr = dir_get_page(inode, n, &page);
+               if (IS_ERR(kaddr))
                        continue;
-               kaddr = (char *)page_address(page);
                p = kaddr+offset;
                limit = kaddr + minix_last_byte(inode, n) - chunk_size;
                for ( ; p <= limit; p = minix_next_entry(p, sbi)) {
@@ -173,11 +175,10 @@ minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
        for (n = 0; n < npages; n++) {
                char *kaddr, *limit;
 
-               page = dir_get_page(dir, n);
-               if (IS_ERR(page))
+               kaddr = dir_get_page(dir, n, &page);
+               if (IS_ERR(kaddr))
                        continue;
 
-               kaddr = (char*)page_address(page);
                limit = kaddr + minix_last_byte(dir, n) - sbi->s_dirsize;
                for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
                        if (sbi->s_version == MINIX_V3) {
@@ -229,12 +230,10 @@ int minix_add_link(struct dentry *dentry, struct inode *inode)
        for (n = 0; n <= npages; n++) {
                char *limit, *dir_end;
 
-               page = dir_get_page(dir, n);
-               err = PTR_ERR(page);
-               if (IS_ERR(page))
-                       goto out;
+               kaddr = dir_get_page(dir, n, &page);
+               if (IS_ERR(kaddr))
+                       return PTR_ERR(kaddr);
                lock_page(page);
-               kaddr = (char*)page_address(page);
                dir_end = kaddr + minix_last_byte(dir, n);
                limit = kaddr + PAGE_SIZE - sbi->s_dirsize;
                for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
@@ -286,7 +285,6 @@ got_it:
        err = minix_handle_dirsync(dir);
 out_put:
        dir_put_page(page);
-out:
        return err;
 out_unlock:
        unlock_page(page);
@@ -375,11 +373,10 @@ int minix_empty_dir(struct inode * inode)
        for (i = 0; i < npages; i++) {
                char *p, *kaddr, *limit;
 
-               page = dir_get_page(inode, i);
-               if (IS_ERR(page))
+               kaddr = dir_get_page(inode, i, &page);
+               if (IS_ERR(kaddr))
                        continue;
 
-               kaddr = (char *)page_address(page);
                limit = kaddr + minix_last_byte(inode, i) - sbi->s_dirsize;
                for (p = kaddr; p <= limit; p = minix_next_entry(p, sbi)) {
                        if (sbi->s_version == MINIX_V3) {
@@ -441,15 +438,12 @@ int minix_set_link(struct minix_dir_entry *de, struct page *page,
 
 struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
 {
-       struct page *page = dir_get_page(dir, 0);
        struct minix_sb_info *sbi = minix_sb(dir->i_sb);
-       struct minix_dir_entry *de = NULL;
+       struct minix_dir_entry *de = dir_get_page(dir, 0, p);
 
-       if (!IS_ERR(page)) {
-               de = minix_next_entry(page_address(page), sbi);
-               *p = page;
-       }
-       return de;
+       if (!IS_ERR(de))
+               return minix_next_entry(de, sbi);
+       return NULL;
 }
 
 ino_t minix_inode_by_name(struct dentry *dentry)