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authorTrond Myklebust <Trond.Myklebust@netapp.com>2008-09-23 17:28:35 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2008-10-06 20:08:26 -0400
commitd5e66348bbe39dc78509e7561f7252aa443df8c0 (patch)
tree7e67858cbc6968d39c17e55499d11d24a958cdab
parent4330ed8ed4da360ac1ca14b0fddff4c05b10de16 (diff)
downloadop-kernel-dev-d5e66348bbe39dc78509e7561f7252aa443df8c0.zip
op-kernel-dev-d5e66348bbe39dc78509e7561f7252aa443df8c0.tar.gz
NFS: Fix nfs_file_llseek()
After the BKL removal patches were applied to the rest of the NFS code, the BKL protection in nfs_file_llseek() is no longer sufficient to ensure that inode->i_size is read safely in generic_file_llseek_unlocked(). In order to fix the situation, we either have to replace the naked read of inode->i_size in generic_file_llseek_unlocked() with i_size_read(), or the whole thing needs to be executed under the inode->i_lock; In order to avoid disrupting other filesystems, avoid touching generic_file_llseek_unlocked() for now... Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
-rw-r--r--fs/nfs/file.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 7846065..3ddb004 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -188,13 +188,16 @@ static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
/* origin == SEEK_END => we must revalidate the cached file length */
if (origin == SEEK_END) {
struct inode *inode = filp->f_mapping->host;
+
int retval = nfs_revalidate_file_size(inode, filp);
if (retval < 0)
return (loff_t)retval;
- }
- lock_kernel(); /* BKL needed? */
- loff = generic_file_llseek_unlocked(filp, offset, origin);
- unlock_kernel();
+
+ spin_lock(&inode->i_lock);
+ loff = generic_file_llseek_unlocked(filp, offset, origin);
+ spin_unlock(&inode->i_lock);
+ } else
+ loff = generic_file_llseek_unlocked(filp, offset, origin);
return loff;
}
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