ufs_inode_getfrag(): split extending the partial blocks off

ufs_extend_tail() is handling that now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 25d47df..d652f64 100644 (file)
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -205,6 +205,40 @@ changed:
        goto again;
 }
 
+/*
+ * Unpacking tails: we have a file with partial final block and
+ * we had been asked to extend it.  If the fragment being written
+ * is within the same block, we need to extend the tail just to cover
+ * that fragment.  Otherwise the tail is extended to full block.
+ *
+ * Note that we might need to create a _new_ tail, but that will
+ * be handled elsewhere; this is strictly for resizing old
+ * ones.
+ */
+static bool
+ufs_extend_tail(struct inode *inode, u64 writes_to,
+                 int *err, struct page *locked_page)
+{
+       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;
+       unsigned lastfrag = ufsi->i_lastfrag;   /* it's a short file, so unsigned is enough */
+       unsigned block = ufs_fragstoblks(lastfrag);
+       unsigned new_size;
+       void *p;
+       u64 tmp;
+
+       if (writes_to < (lastfrag | uspi->s_fpbmask))
+               new_size = (writes_to & uspi->s_fpbmask) + 1;
+       else
+               new_size = uspi->s_fpb;
+
+       p = ufs_get_direct_data_ptr(uspi, ufsi, block);
+       tmp = ufs_new_fragments(inode, p, lastfrag, ufs_data_ptr_to_cpu(sb, p),
+                               new_size, err, locked_page);
+       return tmp != 0;
+}
+
 /**
  * ufs_inode_getfrag() - allocate new fragment(s)
  * @inode: pointer to inode
@@ -226,13 +260,10 @@ ufs_inode_getfrag(struct inode *inode, u64 fragment,
        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;
-       unsigned blockoff, lastblockoff;
-       u64 tmp, goal, lastfrag, block, lastblock;
-       void *p, *p2;
-
-       UFSD("ENTER, ino %lu, fragment %llu, new_fragment %llu, required %u, "
-            "metadata %d\n", inode->i_ino, (unsigned long long)fragment,
-            (unsigned long long)new_fragment, required, !phys);
+       unsigned blockoff;
+       u64 tmp, goal, lastfrag, block;
+       unsigned nfrags = uspi->s_fpb;
+       void *p;
 
         /* TODO : to be done for write support
         if ( (flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2)
@@ -242,66 +273,27 @@ ufs_inode_getfrag(struct inode *inode, u64 fragment,
        block = ufs_fragstoblks (fragment);
        blockoff = ufs_fragnum (fragment);
        p = ufs_get_direct_data_ptr(uspi, ufsi, block);
-
-       goal = 0;
-
        tmp = ufs_data_ptr_to_cpu(sb, p);
+       if (tmp)
+               goto out;
 
        lastfrag = ufsi->i_lastfrag;
-       if (tmp && fragment < lastfrag)
-               goto out;
 
-       lastblock = ufs_fragstoblks (lastfrag);
-       lastblockoff = ufs_fragnum (lastfrag);
-       /*
-        * We will extend file into new block beyond last allocated block
-        */
-       if (lastblock < block) {
-               /*
-                * We must reallocate last allocated block
-                */
-               if (lastblockoff) {
-                       p2 = ufs_get_direct_data_ptr(uspi, ufsi, lastblock);
-                       tmp = ufs_new_fragments(inode, p2, lastfrag,
-                                               ufs_data_ptr_to_cpu(sb, p2),
-                                               uspi->s_fpb - lastblockoff,
-                                               err, locked_page);
-                       if (!tmp)
-                               return 0;
-                       lastfrag = ufsi->i_lastfrag;
-               }
-               tmp = ufs_data_ptr_to_cpu(sb,
-                                        ufs_get_direct_data_ptr(uspi, ufsi,
-                                                                lastblock));
-               if (tmp)
-                       goal = tmp + uspi->s_fpb;
-               tmp = ufs_new_fragments (inode, p, fragment - blockoff,
-                                        goal, required + blockoff,
-                                        err,
-                                        phys != NULL ? locked_page : NULL);
-       } else if (lastblock == block) {
-       /*
-        * We will extend last allocated block
-        */
-               tmp = ufs_new_fragments(inode, p, fragment -
-                                       (blockoff - lastblockoff),
-                                       ufs_data_ptr_to_cpu(sb, p),
-                                       required +  (blockoff - lastblockoff),
-                                       err, phys != NULL ? locked_page : NULL);
-       } else /* (lastblock > block) */ {
-       /*
-        * We will allocate new block before last allocated block
-        */
-               if (block) {
-                       tmp = ufs_data_ptr_to_cpu(sb,
-                                                ufs_get_direct_data_ptr(uspi, ufsi, block - 1));
-                       if (tmp)
-                               goal = tmp + uspi->s_fpb;
-               }
-               tmp = ufs_new_fragments(inode, p, fragment - blockoff,
-                                       goal, uspi->s_fpb, err,
-                                       phys != NULL ? locked_page : NULL);
+       /* will that be a new tail? */
+       if (new_fragment < UFS_NDIR_FRAGMENT && new_fragment >= lastfrag)
+               nfrags = (new_fragment & uspi->s_fpbmask) + 1;
+
+       goal = 0;
+       if (block) {
+               goal = ufs_data_ptr_to_cpu(sb,
+                                ufs_get_direct_data_ptr(uspi, ufsi, block - 1));
+               if (goal)
+                       goal += uspi->s_fpb;
        }
+       tmp = ufs_new_fragments(inode, p, fragment - blockoff,
+                               goal, uspi->s_fpb, err,
+                               phys != NULL ? locked_page : NULL);
+
        if (!tmp) {
                *err = -ENOSPC;
                return 0;
@@ -419,7 +411,6 @@ static int ufs_getfrag_block(struct inode *inode, sector_t fragment, struct buff
        unsigned long ptr,phys;
        u64 phys64 = 0;
        unsigned frag = fragment & uspi->s_fpbmask;
-       unsigned mask = uspi->s_apbmask >> uspi->s_fpbshift;
 
        if (!create) {
                phys64 = ufs_frag_map(inode, offsets, depth);
@@ -444,6 +435,17 @@ static int ufs_getfrag_block(struct inode *inode, sector_t fragment, struct buff
                goto abort_too_big;
 
        err = 0;
+
+       if (UFS_I(inode)->i_lastfrag < UFS_NDIR_FRAGMENT) {
+               unsigned lastfrag = UFS_I(inode)->i_lastfrag;
+               unsigned tailfrags = lastfrag & uspi->s_fpbmask;
+               if (tailfrags && fragment >= lastfrag) {
+                       if (!ufs_extend_tail(inode, fragment,
+                                            &err, bh_result->b_page))
+                               goto abort;
+               }
+       }
+
        ptr = fragment;
 
        if (depth == 1) {