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(-) diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index ee829d3..f7a6553 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -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) -- 1.6.0.2 . ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/NeoTech _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
