f2fs: atomically set inode->i_flags in f2fs_set_inode_flags()
A message that is not in the archive (sent off-list or not yet received): [email protected]
PATCH 1/1 f2fs: atomically set inode->i_flags in f2fs_set_inode_flags()
Use set_mask_bits() to atomically set i_flags instead of clearing out the S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the FS_IMMUTABLE_FL, FS_APPEND_FL, etc. flags, since this opens up a race where an immutable file has the immutable flag cleared for a brief window of time.
Signed-off-by Zhang Zhen <[email protected]>
--- fs/f2fs/inode.c | 17 +++++++++-------- 1 files changed, 9 insertions(+), 8 deletions(-)
fs/f2fs/inode.c +9 -8
@@ -12,6 +12,7 @@#include <linux/f2fs_fs.h> #include <linux/buffer_head.h> #include <linux/writeback.h> +#include <linux/bitops.h> #include "f2fs.h" #include "node.h"
@@ -21,20 +22,20 @@void f2fs_set_inode_flags (struct inode *inode) {unsigned int flags =F2FS_I (inode)->i_flags; - - inode->i_flags &= ~(S_SYNC |S_APPEND |S_IMMUTABLE | -S_NOATIME |S_DIRSYNC ); +unsigned int new_fl =0 ;if (flags &FS_SYNC_FL ) - inode->i_flags |=S_SYNC ; + new_fl |=S_SYNC ;if (flags &FS_APPEND_FL ) - inode->i_flags |=S_APPEND ; + new_fl |=S_APPEND ;if (flags &FS_IMMUTABLE_FL ) - inode->i_flags |=S_IMMUTABLE ; + new_fl |=S_IMMUTABLE ;if (flags &FS_NOATIME_FL ) - inode->i_flags |=S_NOATIME ; + new_fl |=S_NOATIME ;if (flags &FS_DIRSYNC_FL ) - inode->i_flags |=S_DIRSYNC ; + new_fl |=S_DIRSYNC ; +set_mask_bits (&inode->i_flags, +S_SYNC |S_APPEND |S_IMMUTABLE |S_NOATIME |S_DIRSYNC , new_fl); }static void __get_inode_rdev (struct inode *inode,struct f2fs_inode *ri)
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