Btrfs: convert to the new truncate sequence

->truncate() is going away, instead all of the work needs to be done in
->setattr().  So this converts us over to do this.  It's fairly straightforward,
just get rid of our .truncate inode operation and call btrfs_truncate() directly
from btrfs_setsize.  This works out better for us since truncate can technically
return ENOSPC, and before we had no way of letting anybody know.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

1 files changed, 36 insertions, 44 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 2d2e079713d7..3662ffec17d9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -84,7 +84,8 @@ static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
         [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
 };
 
-static void btrfs_truncate(struct inode *inode);
+static int btrfs_setsize(struct inode *inode, loff_t newsize);
+static int btrfs_truncate(struct inode *inode);
 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
 static noinline int cow_file_range(struct inode *inode,
                                    struct page *locked_page,
@@ -2371,6 +2372,11 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
 
                 /* if we have links, this was a truncate, lets do that */
                 if (inode->i_nlink) {
+                        if (!S_ISREG(inode->i_mode)) {
+                                WARN_ON(1);
+                                iput(inode);
+                                continue;
+                        }
                         nr_truncate++;
                         btrfs_truncate(inode);
                 } else {
@@ -3538,7 +3544,7 @@ out:
         return ret;
 }
 
-int btrfs_cont_expand(struct inode *inode, loff_t size)
+int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
 {
         struct btrfs_trans_handle *trans;
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -3546,7 +3552,7 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
         struct extent_map *em = NULL;
         struct extent_state *cached_state = NULL;
         u64 mask = root->sectorsize - 1;
-        u64 hole_start = (inode->i_size + mask) & ~mask;
+        u64 hole_start = (oldsize + mask) & ~mask;
         u64 block_end = (size + mask) & ~mask;
         u64 last_byte;
         u64 cur_offset;
@@ -3617,27 +3623,17 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
         return err;
 }
 
-static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
+static int btrfs_setsize(struct inode *inode, loff_t newsize)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
         struct btrfs_trans_handle *trans;
+        loff_t oldsize = i_size_read(inode);
         unsigned long nr;
         int ret;
 
-        if (attr->ia_size == inode->i_size)
+        if (newsize == oldsize)
                 return 0;
 
-        if (attr->ia_size > inode->i_size) {
-                unsigned long limit;
-                limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-                if (attr->ia_size > inode->i_sb->s_maxbytes)
-                        return -EFBIG;
-                if (limit != RLIM_INFINITY && attr->ia_size > limit) {
-                        send_sig(SIGXFSZ, current, 0);
-                        return -EFBIG;
-                }
-        }
-
         trans = btrfs_start_transaction(root, 5);
         if (IS_ERR(trans))
                 return PTR_ERR(trans);
@@ -3651,16 +3647,16 @@ static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
         btrfs_end_transaction(trans, root);
         btrfs_btree_balance_dirty(root, nr);
 
-        if (attr->ia_size > inode->i_size) {
-                ret = btrfs_cont_expand(inode, attr->ia_size);
+        if (newsize > oldsize) {
+                i_size_write(inode, newsize);
+                btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
+                truncate_pagecache(inode, oldsize, newsize);
+                ret = btrfs_cont_expand(inode, oldsize, newsize);
                 if (ret) {
-                        btrfs_truncate(inode);
+                        btrfs_setsize(inode, oldsize);
                         return ret;
                 }
 
-                i_size_write(inode, attr->ia_size);
-                btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
-
                 trans = btrfs_start_transaction(root, 0);
                 BUG_ON(IS_ERR(trans));
                 btrfs_set_trans_block_group(trans, inode);
@@ -3676,22 +3672,22 @@ static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
                 nr = trans->blocks_used;
                 btrfs_end_transaction(trans, root);
                 btrfs_btree_balance_dirty(root, nr);
-                return 0;
-        }
+        } else {
 
-        /*
-         * We're truncating a file that used to have good data down to
-         * zero. Make sure it gets into the ordered flush list so that
-         * any new writes get down to disk quickly.
-         */
-        if (attr->ia_size == 0)
-                BTRFS_I(inode)->ordered_data_close = 1;
+                /*
+                 * We're truncating a file that used to have good data down to
+                 * zero. Make sure it gets into the ordered flush list so that
+                 * any new writes get down to disk quickly.
+                 */
+                if (newsize == 0)
+                        BTRFS_I(inode)->ordered_data_close = 1;
 
-        /* we don't support swapfiles, so vmtruncate shouldn't fail */
-        ret = vmtruncate(inode, attr->ia_size);
-        BUG_ON(ret);
+                /* we don't support swapfiles, so vmtruncate shouldn't fail */
+                truncate_setsize(inode, newsize);
+                ret = btrfs_truncate(inode);
+        }
 
-        return 0;
+        return ret;
 }
 
 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
@@ -3708,7 +3704,7 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
                 return err;
 
         if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
-                err = btrfs_setattr_size(inode, attr);
+                err = btrfs_setsize(inode, attr->ia_size);
                 if (err)
                         return err;
         }
@@ -6478,7 +6474,7 @@ out:
         return ret;
 }
 
-static void btrfs_truncate(struct inode *inode)
+static int btrfs_truncate(struct inode *inode)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
         int ret;
@@ -6486,14 +6482,9 @@ static void btrfs_truncate(struct inode *inode)
         unsigned long nr;
         u64 mask = root->sectorsize - 1;
 
-        if (!S_ISREG(inode->i_mode)) {
-                WARN_ON(1);
-                return;
-        }
-
         ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
         if (ret)
-                return;
+                return ret;
 
         btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
         btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
@@ -6568,6 +6559,8 @@ static void btrfs_truncate(struct inode *inode)
         ret = btrfs_end_transaction_throttle(trans, root);
         BUG_ON(ret);
         btrfs_btree_balance_dirty(root, nr);
+
+        return ret;
 }
 
 /*
@@ -7367,7 +7360,6 @@ static const struct address_space_operations btrfs_symlink_aops = {
 };
 
 static const struct inode_operations btrfs_file_inode_operations = {
-        .truncate       = btrfs_truncate,
         .getattr        = btrfs_getattr,
         .setattr        = btrfs_setattr,
         .setxattr       = btrfs_setxattr,