diff options
| -rw-r--r-- | fs/xfs/xfs_ialloc.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c index a64dfbd565a5..aad8c5da38af 100644 --- a/fs/xfs/xfs_ialloc.c +++ b/fs/xfs/xfs_ialloc.c @@ -147,6 +147,7 @@ xfs_ialloc_ag_alloc( int version; /* inode version number to use */ int isaligned = 0; /* inode allocation at stripe unit */ /* boundary */ + unsigned int gen; args.tp = tp; args.mp = tp->t_mountp; @@ -290,6 +291,14 @@ xfs_ialloc_ag_alloc( else version = XFS_DINODE_VERSION_1; + /* + * Seed the new inode cluster with a random generation number. This + * prevents short-term reuse of generation numbers if a chunk is + * freed and then immediately reallocated. We use random numbers + * rather than a linear progression to prevent the next generation + * number from being easily guessable. + */ + gen = random32(); for (j = 0; j < nbufs; j++) { /* * Get the block. @@ -309,6 +318,7 @@ xfs_ialloc_ag_alloc( free = XFS_MAKE_IPTR(args.mp, fbuf, i); free->di_core.di_magic = cpu_to_be16(XFS_DINODE_MAGIC); free->di_core.di_version = version; + free->di_core.di_gen = cpu_to_be32(gen); free->di_next_unlinked = cpu_to_be32(NULLAGINO); xfs_ialloc_log_di(tp, fbuf, i, XFS_DI_CORE_BITS | XFS_DI_NEXT_UNLINKED); |