From: Darrick J. Wong <djwong@xxxxxxxxxx>
The previous patch to reload unrecovered unlinked inodes when adding a
newly created inode to the unlinked list is missing a key piece of
functionality. It doesn't handle the case that someone calls xfs_iget
on an inode that is not the last item in the incore list. For example,
if at mount time the ondisk iunlink bucket looks like this:
AGI -> 7 -> 22 -> 3 -> NULL
None of these three inodes are cached in memory. Now let's say that
someone tries to open inode 3 by handle. We need to walk the list to
make sure that inodes 7 and 22 get loaded cold, and that the
i_prev_unlinked of inode 3 gets set to 22.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/xfs_export.c | 6 +++
fs/xfs/xfs_inode.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_inode.h | 9 +++++
fs/xfs/xfs_itable.c | 9 +++++
fs/xfs/xfs_trace.h | 20 ++++++++++
5 files changed, 144 insertions(+)
diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c
index 1064c2342876..f71ea786a6d2 100644
--- a/fs/xfs/xfs_export.c
+++ b/fs/xfs/xfs_export.c
@@ -146,6 +146,12 @@ xfs_nfs_get_inode(
return ERR_PTR(error);
}
+ error = xfs_inode_reload_unlinked(ip);
+ if (error) {
+ xfs_irele(ip);
+ return ERR_PTR(error);
+ }
+
if (VFS_I(ip)->i_generation != generation) {
xfs_irele(ip);
return ERR_PTR(-ESTALE);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 6cd2f29b540a..56f6bde6001b 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3607,3 +3607,103 @@ xfs_iunlock2_io_mmap(
if (ip1 != ip2)
inode_unlock(VFS_I(ip1));
}
+
+/*
+ * Reload the incore inode list for this inode. Caller should ensure that
+ * the link count cannot change, either by taking ILOCK_SHARED or otherwise
+ * preventing other threads from executing.
+ */
+int
+xfs_inode_reload_unlinked_bucket(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_buf *agibp;
+ struct xfs_agi *agi;
+ struct xfs_perag *pag;
+ xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
+ xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
+ xfs_agino_t prev_agino, next_agino;
+ unsigned int bucket;
+ bool foundit = false;
+ int error;
+
+ /* Grab the first inode in the list */
+ pag = xfs_perag_get(mp, agno);
+ error = xfs_ialloc_read_agi(pag, tp, &agibp);
+ xfs_perag_put(pag);
+ if (error)
+ return error;
+
+ bucket = agino % XFS_AGI_UNLINKED_BUCKETS;
+ agi = agibp->b_addr;
+
+ trace_xfs_inode_reload_unlinked_bucket(ip);
+
+ xfs_info_ratelimited(mp,
+ "Found unrecovered unlinked inode 0x%x in AG 0x%x. Initiating list recovery.",
+ agino, agno);
+
+ prev_agino = NULLAGINO;
+ next_agino = be32_to_cpu(agi->agi_unlinked[bucket]);
+ while (next_agino != NULLAGINO) {
+ struct xfs_inode *next_ip = NULL;
+
+ if (next_agino == agino) {
+ /* Found this inode, set its backlink. */
+ next_ip = ip;
+ next_ip->i_prev_unlinked = prev_agino;
+ foundit = true;
+ }
+ if (!next_ip) {
+ /* Inode already in memory. */
+ next_ip = xfs_iunlink_lookup(pag, next_agino);
+ }
+ if (!next_ip) {
+ /* Inode not in memory, reload. */
+ error = xfs_iunlink_reload_next(tp, agibp, prev_agino,
+ next_agino);
+ if (error)
+ break;
+
+ next_ip = xfs_iunlink_lookup(pag, next_agino);
+ }
+ if (!next_ip) {
+ /* No incore inode at all? We reloaded it... */
+ ASSERT(next_ip != NULL);
+ error = -EFSCORRUPTED;
+ break;
+ }
+
+ prev_agino = next_agino;
+ next_agino = next_ip->i_next_unlinked;
+ }
+
+ xfs_trans_brelse(tp, agibp);
+ /* Should have found this inode somewhere in the iunlinked bucket. */
+ if (!error && !foundit)
+ error = -EFSCORRUPTED;
+ return error;
+}
+
+/* Decide if this inode is missing its unlinked list and reload it. */
+int
+xfs_inode_reload_unlinked(
+ struct xfs_inode *ip)
+{
+ struct xfs_trans *tp;
+ int error;
+
+ error = xfs_trans_alloc_empty(ip->i_mount, &tp);
+ if (error)
+ return error;
+
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ if (xfs_inode_unlinked_incomplete(ip))
+ error = xfs_inode_reload_unlinked_bucket(tp, ip);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ xfs_trans_cancel(tp);
+
+ return error;
+}
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 65aae8925509..a111b5551ecd 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -593,4 +593,13 @@ void xfs_end_io(struct work_struct *work);
int xfs_ilock2_io_mmap(struct xfs_inode *ip1, struct xfs_inode *ip2);
void xfs_iunlock2_io_mmap(struct xfs_inode *ip1, struct xfs_inode *ip2);
+static inline bool
+xfs_inode_unlinked_incomplete(
+ struct xfs_inode *ip)
+{
+ return VFS_I(ip)->i_nlink == 0 && !xfs_inode_on_unlinked_list(ip);
+}
+int xfs_inode_reload_unlinked_bucket(struct xfs_trans *tp, struct xfs_inode *ip);
+int xfs_inode_reload_unlinked(struct xfs_inode *ip);
+
#endif /* __XFS_INODE_H__ */
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index f225413a993c..ea38d69b9922 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -80,6 +80,15 @@ xfs_bulkstat_one_int(
if (error)
goto out;
+ if (xfs_inode_unlinked_incomplete(ip)) {
+ error = xfs_inode_reload_unlinked_bucket(tp, ip);
+ if (error) {
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ xfs_irele(ip);
+ return error;
+ }
+ }
+
ASSERT(ip != NULL);
ASSERT(ip->i_imap.im_blkno != 0);
inode = VFS_I(ip);
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index f4e46bac9b91..31418d56618d 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3857,6 +3857,26 @@ TRACE_EVENT(xfs_iunlink_reload_next,
__entry->next_agino)
);
+TRACE_EVENT(xfs_inode_reload_unlinked_bucket,
+ TP_PROTO(struct xfs_inode *ip),
+ TP_ARGS(ip),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agino_t, agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->agno = XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino);
+ __entry->agino = XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino);
+ ),
+ TP_printk("dev %d:%d agno 0x%x agino 0x%x bucket %u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->agino,
+ __entry->agino % XFS_AGI_UNLINKED_BUCKETS)
+);
+
DECLARE_EVENT_CLASS(xfs_ag_inode_class,
TP_PROTO(struct xfs_inode *ip),
TP_ARGS(ip),
