udf: Replace bkl with the UDF_I(inode)->i_data_sem for protect udf_inode_info struct

Replace bkl with the UDF_I(inode)->i_data_sem rw semaphore in
udf_release_file(), udf_symlink(), udf_symlink_filler(), udf_get_block(),
udf_block_map(), and udf_setattr(). The rule now is that any operation
on regular file's or symlink's extents (or generally allocation information
including goal block) needs to hold i_data_sem.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 7 insertions, 5 deletions

diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c
index 16064787d2b7..b1d4488b0f14 100644
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -27,7 +27,6 @@
 #include <linux/mm.h>
 #include <linux/stat.h>
 #include <linux/pagemap.h>
-#include <linux/smp_lock.h>
 #include <linux/buffer_head.h>
 #include "udf_i.h"
 
@@ -78,13 +77,16 @@ static int udf_symlink_filler(struct file *file, struct page *page)
         int err = -EIO;
         unsigned char *p = kmap(page);
         struct udf_inode_info *iinfo;
+        uint32_t pos;
 
-        lock_kernel();
         iinfo = UDF_I(inode);
+        pos = udf_block_map(inode, 0);
+
+        down_read(&iinfo->i_data_sem);
         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
                 symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
         } else {
-                bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
+                bh = sb_bread(inode->i_sb, pos);
 
                 if (!bh)
                         goto out;
@@ -95,14 +97,14 @@ static int udf_symlink_filler(struct file *file, struct page *page)
         udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
         brelse(bh);
 
-        unlock_kernel();
+        up_read(&iinfo->i_data_sem);
         SetPageUptodate(page);
         kunmap(page);
         unlock_page(page);
         return 0;
 
 out:
-        unlock_kernel();
+        up_read(&iinfo->i_data_sem);
         SetPageError(page);
         kunmap(page);
         unlock_page(page);