[PATCH] ufs: truncate should allocate block for last byte
authorEvgeniy Dushistov <dushistov@mail.ru>
Sat, 1 Jul 2006 11:36:24 +0000 (04:36 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sat, 1 Jul 2006 16:56:03 +0000 (09:56 -0700)
This patch fixes buggy behaviour of UFS
in such kind of scenario:
open(, O_TRUNC...)
ftruncate(, 1024)
ftruncate(, 0)

Such a scenario causes ufs_panic and remount read-only.  This happen
because of according to specification UFS should always allocate block for
last byte, and many parts of our implementation rely on this, but
`ufs_truncate' doesn't care about this.

To make possible return error code and to know about old size, this patch
removes `truncate' from ufs inode_operations and uses `setattr' method to
call ufs_truncate.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/ufs/balloc.c
fs/ufs/file.c
fs/ufs/inode.c
fs/ufs/truncate.c
fs/ufs/util.c
fs/ufs/util.h
include/linux/ufs_fs.h

index 95b878e5c7a077783f4971abae30cf9794c91442..b01804baa120f630c1fe2480a970086e96e58cde 100644 (file)
@@ -217,48 +217,6 @@ failed:
        return;
 }
 
-static struct page *ufs_get_locked_page(struct address_space *mapping,
-                                 unsigned long index)
-{
-       struct page *page;
-
-try_again:
-       page = find_lock_page(mapping, index);
-       if (!page) {
-               page = read_cache_page(mapping, index,
-                                      (filler_t*)mapping->a_ops->readpage,
-                                      NULL);
-               if (IS_ERR(page)) {
-                       printk(KERN_ERR "ufs_change_blocknr: "
-                              "read_cache_page error: ino %lu, index: %lu\n",
-                              mapping->host->i_ino, index);
-                       goto out;
-               }
-
-               lock_page(page);
-
-               if (!PageUptodate(page) || PageError(page)) {
-                       unlock_page(page);
-                       page_cache_release(page);
-
-                       printk(KERN_ERR "ufs_change_blocknr: "
-                              "can not read page: ino %lu, index: %lu\n",
-                              mapping->host->i_ino, index);
-
-                       page = ERR_PTR(-EIO);
-                       goto out;
-               }
-       }
-
-       if (unlikely(!page->mapping || !page_has_buffers(page))) {
-               unlock_page(page);
-               page_cache_release(page);
-               goto try_again;/*we really need these buffers*/
-       }
-out:
-       return page;
-}
-
 /*
  * Modify inode page cache in such way:
  * have - blocks with b_blocknr equal to oldb...oldb+count-1
@@ -311,10 +269,8 @@ static void ufs_change_blocknr(struct inode *inode, unsigned int baseblk,
 
                set_page_dirty(page);
 
-               if (likely(cur_index != index)) {
-                       unlock_page(page);
-                       page_cache_release(page);
-               }
+               if (likely(cur_index != index))
+                       ufs_put_locked_page(page);
        }
        UFSD("EXIT\n");
 }
index 0e5001512a9d85f0d176c247096aa96ededddda1..a9c6e5f04faea080ddc271602cab79f829295548 100644 (file)
@@ -60,7 +60,3 @@ const struct file_operations ufs_file_operations = {
        .fsync          = ufs_sync_file,
        .sendfile       = generic_file_sendfile,
 };
-
-struct inode_operations ufs_file_inode_operations = {
-       .truncate       = ufs_truncate,
-};
index 488b5ff48afb1330ca5f40360af42e25231637d3..e7c8615beb65fa31da416c3522390557e582c848 100644 (file)
@@ -843,14 +843,17 @@ int ufs_sync_inode (struct inode *inode)
 
 void ufs_delete_inode (struct inode * inode)
 {
+       loff_t old_i_size;
+
        truncate_inode_pages(&inode->i_data, 0);
        /*UFS_I(inode)->i_dtime = CURRENT_TIME;*/
        lock_kernel();
        mark_inode_dirty(inode);
        ufs_update_inode(inode, IS_SYNC(inode));
+       old_i_size = inode->i_size;
        inode->i_size = 0;
-       if (inode->i_blocks)
-               ufs_truncate (inode);
+       if (inode->i_blocks && ufs_truncate(inode, old_i_size))
+               ufs_warning(inode->i_sb, __FUNCTION__, "ufs_truncate failed\n");
        ufs_free_inode (inode);
        unlock_kernel();
 }
index 3c3b301f87014eeec6327e7480befd367d8ac336..c9b55872079b5a328264021c992ea71a408585db 100644 (file)
@@ -369,24 +369,97 @@ static int ufs_trunc_tindirect (struct inode * inode)
        UFSD("EXIT\n");
        return retry;
 }
-               
-void ufs_truncate (struct inode * inode)
+
+static int ufs_alloc_lastblock(struct inode *inode)
 {
+       int err = 0;
+       struct address_space *mapping = inode->i_mapping;
+       struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
        struct ufs_inode_info *ufsi = UFS_I(inode);
-       struct super_block * sb;
-       struct ufs_sb_private_info * uspi;
-       int retry;
+       unsigned lastfrag, i, end;
+       struct page *lastpage;
+       struct buffer_head *bh;
+
+       lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
+
+       if (!lastfrag) {
+               ufsi->i_lastfrag = 0;
+               goto out;
+       }
+       lastfrag--;
+
+       lastpage = ufs_get_locked_page(mapping, lastfrag >>
+                                      (PAGE_CACHE_SHIFT - inode->i_blkbits));
+       if (IS_ERR(lastpage)) {
+               err = -EIO;
+               goto out;
+       }
+
+       end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
+       bh = page_buffers(lastpage);
+       for (i = 0; i < end; ++i)
+               bh = bh->b_this_page;
+
+       if (!buffer_mapped(bh)) {
+               err = ufs_getfrag_block(inode, lastfrag, bh, 1);
+
+               if (unlikely(err))
+                       goto out_unlock;
+
+               if (buffer_new(bh)) {
+                       clear_buffer_new(bh);
+                       unmap_underlying_metadata(bh->b_bdev,
+                                                bh->b_blocknr);
+                      /*
+                       * we do not zeroize fragment, because of
+                       * if it maped to hole, it already contains zeroes
+                       */
+                       set_buffer_uptodate(bh);
+                       mark_buffer_dirty(bh);
+                       set_page_dirty(lastpage);
+               }
+       }
+out_unlock:
+       ufs_put_locked_page(lastpage);
+out:
+       return err;
+}
+
+int ufs_truncate(struct inode *inode, loff_t old_i_size)
+{
+       struct ufs_inode_info *ufsi = UFS_I(inode);
+       struct super_block *sb = inode->i_sb;
+       struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
+       int retry, err = 0;
        
        UFSD("ENTER\n");
-       sb = inode->i_sb;
-       uspi = UFS_SB(sb)->s_uspi;
 
-       if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
-               return;
+       if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+             S_ISLNK(inode->i_mode)))
+               return -EINVAL;
        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
-               return;
+               return -EPERM;
+
+       if (inode->i_size > old_i_size) {
+               /*
+                * if we expand file we should care about
+                * allocation of block for last byte first of all
+                */
+               err = ufs_alloc_lastblock(inode);
+
+               if (err) {
+                       i_size_write(inode, old_i_size);
+                       goto out;
+               }
+               /*
+                * go away, because of we expand file, and we do not
+                * need free blocks, and zeroizes page
+                */
+               lock_kernel();
+               goto almost_end;
+       }
 
-       block_truncate_page(inode->i_mapping,   inode->i_size, ufs_getfrag_block);
+       block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
 
        lock_kernel();
        while (1) {
@@ -404,9 +477,58 @@ void ufs_truncate (struct inode * inode)
                yield();
        }
 
+       if (inode->i_size < old_i_size) {
+               /*
+                * now we should have enough space
+                * to allocate block for last byte
+                */
+               err = ufs_alloc_lastblock(inode);
+               if (err)
+                       /*
+                        * looks like all the same - we have no space,
+                        * but we truncate file already
+                        */
+                       inode->i_size = (ufsi->i_lastfrag - 1) * uspi->s_fsize;
+       }
+almost_end:
        inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
-       ufsi->i_lastfrag = DIRECT_FRAGMENT;
        unlock_kernel();
        mark_inode_dirty(inode);
-       UFSD("EXIT\n");
+out:
+       UFSD("EXIT: err %d\n", err);
+       return err;
 }
+
+
+/*
+ * We don't define our `inode->i_op->truncate', and call it here,
+ * because of:
+ * - there is no way to know old size
+ * - there is no way inform user about error, if it happens in `truncate'
+ */
+static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+       struct inode *inode = dentry->d_inode;
+       unsigned int ia_valid = attr->ia_valid;
+       int error;
+
+       error = inode_change_ok(inode, attr);
+       if (error)
+               return error;
+
+       if (ia_valid & ATTR_SIZE &&
+           attr->ia_size != i_size_read(inode)) {
+               loff_t old_i_size = inode->i_size;
+               error = vmtruncate(inode, attr->ia_size);
+               if (error)
+                       return error;
+               error = ufs_truncate(inode, old_i_size);
+               if (error)
+                       return error;
+       }
+       return inode_setattr(inode, attr);
+}
+
+struct inode_operations ufs_file_inode_operations = {
+       .setattr = ufs_setattr,
+};
index a2f13f45708b7d0fa6d688579f3551176465f3bd..337cf2c46d109f1e9c9cef3492ed2dd26bffe07e 100644 (file)
@@ -233,3 +233,57 @@ ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev
        else
                ufsi->i_u1.i_data[0] = fs32;
 }
+
+/**
+ * ufs_get_locked_page() - locate, pin and lock a pagecache page, if not exist
+ * read it from disk.
+ * @mapping: the address_space to search
+ * @index: the page index
+ *
+ * Locates the desired pagecache page, if not exist we'll read it,
+ * locks it, increments its reference
+ * count and returns its address.
+ *
+ */
+
+struct page *ufs_get_locked_page(struct address_space *mapping,
+                                pgoff_t index)
+{
+       struct page *page;
+
+try_again:
+       page = find_lock_page(mapping, index);
+       if (!page) {
+               page = read_cache_page(mapping, index,
+                                      (filler_t*)mapping->a_ops->readpage,
+                                      NULL);
+               if (IS_ERR(page)) {
+                       printk(KERN_ERR "ufs_change_blocknr: "
+                              "read_cache_page error: ino %lu, index: %lu\n",
+                              mapping->host->i_ino, index);
+                       goto out;
+               }
+
+               lock_page(page);
+
+               if (!PageUptodate(page) || PageError(page)) {
+                       unlock_page(page);
+                       page_cache_release(page);
+
+                       printk(KERN_ERR "ufs_change_blocknr: "
+                              "can not read page: ino %lu, index: %lu\n",
+                              mapping->host->i_ino, index);
+
+                       page = ERR_PTR(-EIO);
+                       goto out;
+               }
+       }
+
+       if (unlikely(!page->mapping || !page_has_buffers(page))) {
+               unlock_page(page);
+               page_cache_release(page);
+               goto try_again;/*we really need these buffers*/
+       }
+out:
+       return page;
+}
index 406981fff5e7ca01317a7aa26c34f803827ec7fc..28fce6c239b56f8d960a7bf7a820c12ad1b2b3e4 100644 (file)
@@ -251,6 +251,14 @@ extern void _ubh_ubhcpymem_(struct ufs_sb_private_info *, unsigned char *, struc
 #define ubh_memcpyubh(ubh,mem,size) _ubh_memcpyubh_(uspi,ubh,mem,size)
 extern void _ubh_memcpyubh_(struct ufs_sb_private_info *, struct ufs_buffer_head *, unsigned char *, unsigned);
 
+/* This functions works with cache pages*/
+extern struct page *ufs_get_locked_page(struct address_space *mapping,
+                                       pgoff_t index);
+static inline void ufs_put_locked_page(struct page *page)
+{
+       unlock_page(page);
+       page_cache_release(page);
+}
 
 
 /*
index e39b7cc433902565d9b7aa5d450f5be86a10118b..fc62887c5206628d78279a1480628e6448c154a1 100644 (file)
@@ -993,7 +993,7 @@ extern void ufs_panic (struct super_block *, const char *, const char *, ...) __
 extern struct inode_operations ufs_fast_symlink_inode_operations;
 
 /* truncate.c */
-extern void ufs_truncate (struct inode *);
+extern int ufs_truncate (struct inode *, loff_t);
 
 static inline struct ufs_sb_info *UFS_SB(struct super_block *sb)
 {