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Diffstat (limited to 'fs/xfs/xfs_ialloc.c')
-rw-r--r--fs/xfs/xfs_ialloc.c10
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);