diff options
Diffstat (limited to 'fs/xfs/scrub/tempfile.c')
| -rw-r--r-- | fs/xfs/scrub/tempfile.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/fs/xfs/scrub/tempfile.c b/fs/xfs/scrub/tempfile.c new file mode 100644 index 000000000000..5ff376d228db --- /dev/null +++ b/fs/xfs/scrub/tempfile.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2021 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_xchgrange.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 swapping 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); + bool use_log = false; + int error; + + if (xfs_is_shutdown(mp)) + return -EIO; + if (xfs_is_readonly(mp)) + return -EROFS; + + ASSERT(sc->tp == NULL); + ASSERT(sc->tempip == NULL); + + /* Enable atomic extent swapping. */ + error = xfs_xchg_range_grab_log_assist(mp, true, &use_log); + if (error) + return error; + ASSERT(use_log); + sc->flags |= XREP_ATOMIC_EXCHANGE; + + /* + * 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(&init_user_ns, 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; + 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. + * Anything being reconstructed using this file must be atomically + * swapped 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); + xfs_irele(sc->tempip); + } +out_release_dquots: + xfs_qm_dqrele(udqp); + xfs_qm_dqrele(gdqp); + xfs_qm_dqrele(pdqp); + + return error; +} + +void +xrep_tempfile_ilock( + struct xfs_scrub *sc, + unsigned int ilock_flags) +{ + sc->temp_ilock_flags |= ilock_flags; + xfs_ilock(sc->tempip, ilock_flags); +} + +bool +xrep_tempfile_ilock_nowait( + struct xfs_scrub *sc, + unsigned int ilock_flags) +{ + if (xfs_ilock_nowait(sc->tempip, ilock_flags)) { + sc->temp_ilock_flags |= ilock_flags; + return true; + } + + return false; +} + +void +xrep_tempfile_iunlock( + struct xfs_scrub *sc, + unsigned int ilock_flags) +{ + xfs_iunlock(sc->tempip, ilock_flags); + sc->temp_ilock_flags &= ~ilock_flags; +} + +/* Release the temporary file. */ +void +xrep_tempfile_rele( + struct xfs_scrub *sc) +{ + if (!sc->tempip) + return; + + if (sc->temp_ilock_flags) + xrep_tempfile_iunlock(sc, sc->temp_ilock_flags); + xfs_irele(sc->tempip); + sc->tempip = NULL; +} |