--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2021-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_inode.h"
+#include "xfs_ialloc.h"
+#include "xfs_quota.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_trans_space.h"
+#include "xfs_dir2.h"
+#include "xfs_exchrange.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/tempfile.h"
+
+/*
+ * Create a temporary file for reconstructing metadata, with the intention of
+ * atomically exchanging the temporary file's contents with the file that's
+ * being repaired.
+ */
+int
+xrep_tempfile_create(
+ struct xfs_scrub *sc,
+ uint16_t mode)
+{
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_trans *tp = NULL;
+ struct xfs_dquot *udqp = NULL;
+ struct xfs_dquot *gdqp = NULL;
+ struct xfs_dquot *pdqp = NULL;
+ struct xfs_trans_res *tres;
+ struct xfs_inode *dp = mp->m_rootip;
+ xfs_ino_t ino;
+ unsigned int resblks;
+ bool is_dir = S_ISDIR(mode);
+ int error;
+
+ if (xfs_is_shutdown(mp))
+ return -EIO;
+ if (xfs_is_readonly(mp))
+ return -EROFS;
+
+ ASSERT(sc->tp == NULL);
+ ASSERT(sc->tempip == NULL);
+
+ /*
+ * Make sure that we have allocated dquot(s) on disk. The temporary
+ * inode should be completely root owned so that we don't fail due to
+ * quota limits.
+ */
+ error = xfs_qm_vop_dqalloc(dp, GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
+ XFS_QMOPT_QUOTALL, &udqp, &gdqp, &pdqp);
+ if (error)
+ return error;
+
+ if (is_dir) {
+ resblks = XFS_MKDIR_SPACE_RES(mp, 0);
+ tres = &M_RES(mp)->tr_mkdir;
+ } else {
+ resblks = XFS_IALLOC_SPACE_RES(mp);
+ tres = &M_RES(mp)->tr_create_tmpfile;
+ }
+
+ error = xfs_trans_alloc_icreate(mp, tres, udqp, gdqp, pdqp, resblks,
+ &tp);
+ if (error)
+ goto out_release_dquots;
+
+ /* Allocate inode, set up directory. */
+ error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
+ if (error)
+ goto out_trans_cancel;
+ error = xfs_init_new_inode(&nop_mnt_idmap, tp, dp, ino, mode, 0, 0,
+ 0, false, &sc->tempip);
+ if (error)
+ goto out_trans_cancel;
+
+ /* Change the ownership of the inode to root. */
+ VFS_I(sc->tempip)->i_uid = GLOBAL_ROOT_UID;
+ VFS_I(sc->tempip)->i_gid = GLOBAL_ROOT_GID;
+ sc->tempip->i_diflags &= ~(XFS_DIFLAG_REALTIME | XFS_DIFLAG_RTINHERIT);
+ xfs_trans_log_inode(tp, sc->tempip, XFS_ILOG_CORE);
+
+ /*
+ * Mark our temporary file as private so that LSMs and the ACL code
+ * don't try to add their own metadata or reason about these files.
+ * The file should never be exposed to userspace.
+ */
+ VFS_I(sc->tempip)->i_flags |= S_PRIVATE;
+ VFS_I(sc->tempip)->i_opflags &= ~IOP_XATTR;
+
+ if (is_dir) {
+ error = xfs_dir_init(tp, sc->tempip, dp);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /*
+ * Attach the dquot(s) to the inodes and modify them incore.
+ * These ids of the inode couldn't have changed since the new
+ * inode has been locked ever since it was created.
+ */
+ xfs_qm_vop_create_dqattach(tp, sc->tempip, udqp, gdqp, pdqp);
+
+ /*
+ * Put our temp file on the unlinked list so it's purged automatically.
+ * All file-based metadata being reconstructed using this file must be
+ * atomically exchanged with the original file because the contents
+ * here will be purged when the inode is dropped or log recovery cleans
+ * out the unlinked list.
+ */
+ error = xfs_iunlink(tp, sc->tempip);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_trans_commit(tp);
+ if (error)
+ goto out_release_inode;
+
+ trace_xrep_tempfile_create(sc);
+
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+ xfs_qm_dqrele(pdqp);
+
+ /* Finish setting up the incore / vfs context. */
+ xfs_setup_iops(sc->tempip);
+ xfs_finish_inode_setup(sc->tempip);
+
+ sc->temp_ilock_flags = 0;
+ return error;
+
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+out_release_inode:
+ /*
+ * Wait until after the current transaction is aborted to finish the
+ * setup of the inode and release the inode. This prevents recursive
+ * transactions and deadlocks from xfs_inactive.
+ */
+ if (sc->tempip) {
+ xfs_finish_inode_setup(sc->tempip);
+ xchk_irele(sc, sc->tempip);
+ }
+out_release_dquots:
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+ xfs_qm_dqrele(pdqp);
+
+ return error;
+}
+
+/* Take IOLOCK_EXCL on the temporary file, maybe. */
+bool
+xrep_tempfile_iolock_nowait(
+ struct xfs_scrub *sc)
+{
+ if (xfs_ilock_nowait(sc->tempip, XFS_IOLOCK_EXCL)) {
+ sc->temp_ilock_flags |= XFS_IOLOCK_EXCL;
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * Take the temporary file's IOLOCK while holding a different inode's IOLOCK.
+ * In theory nobody else should hold the tempfile's IOLOCK, but we use trylock
+ * to avoid deadlocks and lockdep complaints.
+ */
+int
+xrep_tempfile_iolock_polled(
+ struct xfs_scrub *sc)
+{
+ int error = 0;
+
+ while (!xrep_tempfile_iolock_nowait(sc)) {
+ if (xchk_should_terminate(sc, &error))
+ return error;
+ delay(1);
+ }
+
+ return 0;
+}
+
+/* Release IOLOCK_EXCL on the temporary file. */
+void
+xrep_tempfile_iounlock(
+ struct xfs_scrub *sc)
+{
+ xfs_iunlock(sc->tempip, XFS_IOLOCK_EXCL);
+ sc->temp_ilock_flags &= ~XFS_IOLOCK_EXCL;
+}
+
+/* Prepare the temporary file for metadata updates by grabbing ILOCK_EXCL. */
+void
+xrep_tempfile_ilock(
+ struct xfs_scrub *sc)
+{
+ sc->temp_ilock_flags |= XFS_ILOCK_EXCL;
+ xfs_ilock(sc->tempip, XFS_ILOCK_EXCL);
+}
+
+/* Try to grab ILOCK_EXCL on the temporary file. */
+bool
+xrep_tempfile_ilock_nowait(
+ struct xfs_scrub *sc)
+{
+ if (xfs_ilock_nowait(sc->tempip, XFS_ILOCK_EXCL)) {
+ sc->temp_ilock_flags |= XFS_ILOCK_EXCL;
+ return true;
+ }
+
+ return false;
+}
+
+/* Unlock ILOCK_EXCL on the temporary file after an update. */
+void
+xrep_tempfile_iunlock(
+ struct xfs_scrub *sc)
+{
+ xfs_iunlock(sc->tempip, XFS_ILOCK_EXCL);
+ sc->temp_ilock_flags &= ~XFS_ILOCK_EXCL;
+}
+
+/* Release the temporary file. */
+void
+xrep_tempfile_rele(
+ struct xfs_scrub *sc)
+{
+ if (!sc->tempip)
+ return;
+
+ if (sc->temp_ilock_flags) {
+ xfs_iunlock(sc->tempip, sc->temp_ilock_flags);
+ sc->temp_ilock_flags = 0;
+ }
+
+ xchk_irele(sc, sc->tempip);
+ sc->tempip = NULL;
+}
__entry->flags)
);
+TRACE_EVENT(xrep_tempfile_create,
+ TP_PROTO(struct xfs_scrub *sc),
+ TP_ARGS(sc),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ __field(unsigned int, type)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_ino_t, inum)
+ __field(unsigned int, gen)
+ __field(unsigned int, flags)
+ __field(xfs_ino_t, temp_inum)
+ ),
+ TP_fast_assign(
+ __entry->dev = sc->mp->m_super->s_dev;
+ __entry->ino = sc->file ? XFS_I(file_inode(sc->file))->i_ino : 0;
+ __entry->type = sc->sm->sm_type;
+ __entry->agno = sc->sm->sm_agno;
+ __entry->inum = sc->sm->sm_ino;
+ __entry->gen = sc->sm->sm_gen;
+ __entry->flags = sc->sm->sm_flags;
+ __entry->temp_inum = sc->tempip->i_ino;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx type %s inum 0x%llx gen 0x%x flags 0x%x temp_inum 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __print_symbolic(__entry->type, XFS_SCRUB_TYPE_STRINGS),
+ __entry->inum,
+ __entry->gen,
+ __entry->flags,
+ __entry->temp_inum)
+);
+
#endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
#endif /* _TRACE_XFS_SCRUB_TRACE_H */
projects / thirdparty / kernel / linux.git / commitdiff
