// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_inode.h" #include "xfs_acl.h" #include "xfs_quota.h" #include "xfs_attr.h" #include "xfs_trans.h" #include "xfs_trace.h" #include "xfs_icache.h" #include "xfs_symlink.h" #include "xfs_dir2.h" #include "xfs_iomap.h" #include "xfs_error.h" #include <linux/posix_acl.h> #include <linux/security.h> #include <linux/iversion.h> #include <linux/fiemap.h> /* * Directories have different lock order w.r.t. mmap_lock compared to regular * files. This is due to readdir potentially triggering page faults on a user * buffer inside filldir(), and this happens with the ilock on the directory * held. For regular files, the lock order is the other way around - the * mmap_lock is taken during the page fault, and then we lock the ilock to do * block mapping. Hence we need a different class for the directory ilock so * that lockdep can tell them apart. */ static struct lock_class_key xfs_nondir_ilock_class; static struct lock_class_key xfs_dir_ilock_class; static int xfs_initxattrs( struct inode *inode, const struct xattr *xattr_array, void *fs_info) { const struct xattr *xattr; struct xfs_inode *ip = XFS_I(inode); int error = 0; for (xattr = xattr_array; xattr->name != NULL; xattr++) { struct xfs_da_args args = { .dp = ip, .attr_filter = XFS_ATTR_SECURE, .name = xattr->name, .namelen = strlen(xattr->name), .value = xattr->value, .valuelen = xattr->value_len, }; error = xfs_attr_set(&args); if (error < 0) break; } return error; } /* * Hook in SELinux. This is not quite correct yet, what we really need * here (as we do for default ACLs) is a mechanism by which creation of * these attrs can be journalled at inode creation time (along with the * inode, of course, such that log replay can't cause these to be lost). */ STATIC int xfs_init_security( struct inode *inode, struct inode *dir, const struct qstr *qstr) { return security_inode_init_security(inode, dir, qstr, &xfs_initxattrs, NULL); } static void xfs_dentry_to_name( struct xfs_name *namep, struct dentry *dentry) { namep->name = dentry->d_name.name; namep->len = dentry->d_name.len; namep->type = XFS_DIR3_FT_UNKNOWN; } static int xfs_dentry_mode_to_name( struct xfs_name *namep, struct dentry *dentry, int mode) { namep->name = dentry->d_name.name; namep->len = dentry->d_name.len; namep->type = xfs_mode_to_ftype(mode); if (unlikely(namep->type == XFS_DIR3_FT_UNKNOWN)) return -EFSCORRUPTED; return 0; } STATIC void xfs_cleanup_inode( struct inode *dir, struct inode *inode, struct dentry *dentry) { struct xfs_name teardown; /* Oh, the horror. * If we can't add the ACL or we fail in * xfs_init_security we must back out. * ENOSPC can hit here, among other things. */ xfs_dentry_to_name(&teardown, dentry); xfs_remove(XFS_I(dir), &teardown, XFS_I(inode)); } STATIC int xfs_generic_create( struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev, bool tmpfile) /* unnamed file */ { struct inode *inode; struct xfs_inode *ip = NULL; struct posix_acl *default_acl, *acl; struct xfs_name name; int error; /* * Irix uses Missed'em'V split, but doesn't want to see * the upper 5 bits of (14bit) major. */ if (S_ISCHR(mode) || S_ISBLK(mode)) { if (unlikely(!sysv_valid_dev(rdev) || MAJOR(rdev) & ~0x1ff)) return -EINVAL; } else { rdev = 0; } error = posix_acl_create(dir, &mode, &default_acl, &acl); if (error) return error; /* Verify mode is valid also for tmpfile case */ error = xfs_dentry_mode_to_name(&name, dentry, mode); if (unlikely(error)) goto out_free_acl; if (!tmpfile) { error = xfs_create(XFS_I(dir), &name, mode, rdev, &ip); } else { error = xfs_create_tmpfile(XFS_I(dir), mode, &ip); } if (unlikely(error)) goto out_free_acl; inode = VFS_I(ip); error = xfs_init_security(inode, dir, &dentry->d_name); if (unlikely(error)) goto out_cleanup_inode; #ifdef CONFIG_XFS_POSIX_ACL if (default_acl) { error = __xfs_set_acl(inode, default_acl, ACL_TYPE_DEFAULT); if (error) goto out_cleanup_inode; } if (acl) { error = __xfs_set_acl(inode, acl, ACL_TYPE_ACCESS); if (error) goto out_cleanup_inode; } #endif xfs_setup_iops(ip); if (tmpfile) { /* * The VFS requires that any inode fed to d_tmpfile must have * nlink == 1 so that it can decrement the nlink in d_tmpfile. * However, we created the temp file with nlink == 0 because * we're not allowed to put an inode with nlink > 0 on the * unlinked list. Therefore we have to set nlink to 1 so that * d_tmpfile can immediately set it back to zero. */ set_nlink(inode, 1); d_tmpfile(dentry, inode); } else d_instantiate(dentry, inode); xfs_finish_inode_setup(ip); out_free_acl: if (default_acl) posix_acl_release(default_acl); if (acl) posix_acl_release(acl); return error; out_cleanup_inode: xfs_finish_inode_setup(ip); if (!tmpfile) xfs_cleanup_inode(dir, inode, dentry); xfs_irele(ip); goto out_free_acl; } STATIC int xfs_vn_mknod( struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { return xfs_generic_create(dir, dentry, mode, rdev, false); } STATIC int xfs_vn_create( struct inode *dir, struct dentry *dentry, umode_t mode, bool flags) { return xfs_generic_create(dir, dentry, mode, 0, false); } STATIC int xfs_vn_mkdir( struct inode *dir, struct dentry *dentry, umode_t mode) { return xfs_generic_create(dir, dentry, mode | S_IFDIR, 0, false); } STATIC struct dentry * xfs_vn_lookup( struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; struct xfs_inode *cip; struct xfs_name name; int error; if (dentry->d_name.len >= MAXNAMELEN) return ERR_PTR(-ENAMETOOLONG); xfs_dentry_to_name(&name, dentry); error = xfs_lookup(XFS_I(dir), &name, &cip, NULL); if (likely(!error)) inode = VFS_I(cip); else if (likely(error == -ENOENT)) inode = NULL; else inode = ERR_PTR(error); return d_splice_alias(inode, dentry); } STATIC struct dentry * xfs_vn_ci_lookup( struct inode *dir, struct dentry *dentry, unsigned int flags) { struct xfs_inode *ip; struct xfs_name xname; struct xfs_name ci_name; struct qstr dname; int error; if (dentry->d_name.len >= MAXNAMELEN) return ERR_PTR(-ENAMETOOLONG); xfs_dentry_to_name(&xname, dentry); error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name); if (unlikely(error)) { if (unlikely(error != -ENOENT)) return ERR_PTR(error); /* * call d_add(dentry, NULL) here when d_drop_negative_children * is called in xfs_vn_mknod (ie. allow negative dentries * with CI filesystems). */ return NULL; } /* if exact match, just splice and exit */ if (!ci_name.name) return d_splice_alias(VFS_I(ip), dentry); /* else case-insensitive match... */ dname.name = ci_name.name; dname.len = ci_name.len; dentry = d_add_ci(dentry, VFS_I(ip), &dname); kmem_free(ci_name.name); return dentry; } STATIC int xfs_vn_link( struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct inode *inode = d_inode(old_dentry); struct xfs_name name; int error; error = xfs_dentry_mode_to_name(&name, dentry, inode->i_mode); if (unlikely(error)) return error; error = xfs_link(XFS_I(dir), XFS_I(inode), &name); if (unlikely(error)) return error; ihold(inode); d_instantiate(dentry, inode); return 0; } STATIC int xfs_vn_unlink( struct inode *dir, struct dentry *dentry) { struct xfs_name name; int error; xfs_dentry_to_name(&name, dentry); error = xfs_remove(XFS_I(dir), &name, XFS_I(d_inode(dentry))); if (error) return error; /* * With unlink, the VFS makes the dentry "negative": no inode, * but still hashed. This is incompatible with case-insensitive * mode, so invalidate (unhash) the dentry in CI-mode. */ if (xfs_sb_version_hasasciici(&XFS_M(dir->i_sb)->m_sb)) d_invalidate(dentry); return 0; } STATIC int xfs_vn_symlink( struct inode *dir, struct dentry *dentry, const char *symname) { struct inode *inode; struct xfs_inode *cip = NULL; struct xfs_name name; int error; umode_t mode; mode = S_IFLNK | (irix_symlink_mode ? 0777 & ~current_umask() : S_IRWXUGO); error = xfs_dentry_mode_to_name(&name, dentry, mode); if (unlikely(error)) goto out; error = xfs_symlink(XFS_I(dir), &name, symname, mode, &cip); if (unlikely(error)) goto out; inode = VFS_I(cip); error = xfs_init_security(inode, dir, &dentry->d_name); if (unlikely(error)) goto out_cleanup_inode; xfs_setup_iops(cip); d_instantiate(dentry, inode); xfs_finish_inode_setup(cip); return 0; out_cleanup_inode: xfs_finish_inode_setup(cip); xfs_cleanup_inode(dir, inode, dentry); xfs_irele(cip); out: return error; } STATIC int xfs_vn_rename( struct inode *odir, struct dentry *odentry, struct inode *ndir, struct dentry *ndentry, unsigned int flags) { struct inode *new_inode = d_inode(ndentry); int omode = 0; int error; struct xfs_name oname; struct xfs_name nname; if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) return -EINVAL; /* if we are exchanging files, we need to set i_mode of both files */ if (flags & RENAME_EXCHANGE) omode = d_inode(ndentry)->i_mode; error = xfs_dentry_mode_to_name(&oname, odentry, omode); if (omode && unlikely(error)) return error; error = xfs_dentry_mode_to_name(&nname, ndentry, d_inode(odentry)->i_mode); if (unlikely(error)) return error; return xfs_rename(XFS_I(odir), &oname, XFS_I(d_inode(odentry)), XFS_I(ndir), &nname, new_inode ? XFS_I(new_inode) : NULL, flags); } /* * careful here - this function can get called recursively, so * we need to be very careful about how much stack we use. * uio is kmalloced for this reason... */ STATIC const char * xfs_vn_get_link( struct dentry *dentry, struct inode *inode, struct delayed_call *done) { char *link; int error = -ENOMEM; if (!dentry) return ERR_PTR(-ECHILD); link = kmalloc(XFS_SYMLINK_MAXLEN+1, GFP_KERNEL); if (!link) goto out_err; error = xfs_readlink(XFS_I(d_inode(dentry)), link); if (unlikely(error)) goto out_kfree; set_delayed_call(done, kfree_link, link); return link; out_kfree: kfree(link); out_err: return ERR_PTR(error); } STATIC const char * xfs_vn_get_link_inline( struct dentry *dentry, struct inode *inode, struct delayed_call *done) { struct xfs_inode *ip = XFS_I(inode); char *link; ASSERT(ip->i_df.if_flags & XFS_IFINLINE); /* * The VFS crashes on a NULL pointer, so return -EFSCORRUPTED if * if_data is junk. */ link = ip->i_df.if_u1.if_data; if (XFS_IS_CORRUPT(ip->i_mount, !link)) return ERR_PTR(-EFSCORRUPTED); return link; } static uint32_t xfs_stat_blksize( struct xfs_inode *ip) { struct xfs_mount *mp = ip->i_mount; /* * If the file blocks are being allocated from a realtime volume, then * always return the realtime extent size. */ if (XFS_IS_REALTIME_INODE(ip)) return xfs_get_extsz_hint(ip) << mp->m_sb.sb_blocklog; /* * Allow large block sizes to be reported to userspace programs if the * "largeio" mount option is used. * * If compatibility mode is specified, simply return the basic unit of * caching so that we don't get inefficient read/modify/write I/O from * user apps. Otherwise.... * * If the underlying volume is a stripe, then return the stripe width in * bytes as the recommended I/O size. It is not a stripe and we've set a * default buffered I/O size, return that, otherwise return the compat * default. */ if (mp->m_flags & XFS_MOUNT_LARGEIO) { if (mp->m_swidth) return mp->m_swidth << mp->m_sb.sb_blocklog; if (mp->m_flags & XFS_MOUNT_ALLOCSIZE) return 1U << mp->m_allocsize_log; } return PAGE_SIZE; } STATIC int xfs_vn_getattr( const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *inode = d_inode(path->dentry); struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; trace_xfs_getattr(ip); if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; stat->size = XFS_ISIZE(ip); stat->dev = inode->i_sb->s_dev; stat->mode = inode->i_mode; stat->nlink = inode->i_nlink; stat->uid = inode->i_uid; stat->gid = inode->i_gid; stat->ino = ip->i_ino; stat->atime = inode->i_atime; stat->mtime = inode->i_mtime; stat->ctime = inode->i_ctime; stat->blocks = XFS_FSB_TO_BB(mp, ip->i_d.di_nblocks + ip->i_delayed_blks); if (xfs_sb_version_has_v3inode(&mp->m_sb)) { if (request_mask & STATX_BTIME) { stat->result_mask |= STATX_BTIME; stat->btime = ip->i_d.di_crtime; } } /* * Note: If you add another clause to set an attribute flag, please * update attributes_mask below. */ if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE) stat->attributes |= STATX_ATTR_IMMUTABLE; if (ip->i_d.di_flags & XFS_DIFLAG_APPEND) stat->attributes |= STATX_ATTR_APPEND; if (ip->i_d.di_flags & XFS_DIFLAG_NODUMP) stat->attributes |= STATX_ATTR_NODUMP; stat->attributes_mask |= (STATX_ATTR_IMMUTABLE | STATX_ATTR_APPEND | STATX_ATTR_NODUMP); switch (inode->i_mode & S_IFMT) { case S_IFBLK: case S_IFCHR: stat->blksize = BLKDEV_IOSIZE; stat->rdev = inode->i_rdev; break; default: stat->blksize = xfs_stat_blksize(ip); stat->rdev = 0; break; } return 0; } static void xfs_setattr_mode( struct xfs_inode *ip, struct iattr *iattr) { struct inode *inode = VFS_I(ip); umode_t mode = iattr->ia_mode; ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); inode->i_mode &= S_IFMT; inode->i_mode |= mode & ~S_IFMT; } void xfs_setattr_time( struct xfs_inode *ip, struct iattr *iattr) { struct inode *inode = VFS_I(ip); ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); if (iattr->ia_valid & ATTR_ATIME) inode->i_atime = iattr->ia_atime; if (iattr->ia_valid & ATTR_CTIME) inode->i_ctime = iattr->ia_ctime; if (iattr->ia_valid & ATTR_MTIME) inode->i_mtime = iattr->ia_mtime; } static int xfs_vn_change_ok( struct dentry *dentry, struct iattr *iattr) { struct xfs_mount *mp = XFS_I(d_inode(dentry))->i_mount; if (mp->m_flags & XFS_MOUNT_RDONLY) return -EROFS; if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; return setattr_prepare(dentry, iattr); } /* * Set non-size attributes of an inode. * * Caution: The caller of this function is responsible for calling * setattr_prepare() or otherwise verifying the change is fine. */ int xfs_setattr_nonsize( struct xfs_inode *ip, struct iattr *iattr, int flags) { xfs_mount_t *mp = ip->i_mount; struct inode *inode = VFS_I(ip); int mask = iattr->ia_valid; xfs_trans_t *tp; int error; kuid_t uid = GLOBAL_ROOT_UID, iuid = GLOBAL_ROOT_UID; kgid_t gid = GLOBAL_ROOT_GID, igid = GLOBAL_ROOT_GID; struct xfs_dquot *udqp = NULL, *gdqp = NULL; struct xfs_dquot *olddquot1 = NULL, *olddquot2 = NULL; ASSERT((mask & ATTR_SIZE) == 0); /* * If disk quotas is on, we make sure that the dquots do exist on disk, * before we start any other transactions. Trying to do this later * is messy. We don't care to take a readlock to look at the ids * in inode here, because we can't hold it across the trans_reserve. * If the IDs do change before we take the ilock, we're covered * because the i_*dquot fields will get updated anyway. */ if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) { uint qflags = 0; if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) { uid = iattr->ia_uid; qflags |= XFS_QMOPT_UQUOTA; } else { uid = inode->i_uid; } if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) { gid = iattr->ia_gid; qflags |= XFS_QMOPT_GQUOTA; } else { gid = inode->i_gid; } /* * We take a reference when we initialize udqp and gdqp, * so it is important that we never blindly double trip on * the same variable. See xfs_create() for an example. */ ASSERT(udqp == NULL); ASSERT(gdqp == NULL); error = xfs_qm_vop_dqalloc(ip, uid, gid, ip->i_d.di_projid, qflags, &udqp, &gdqp, NULL); if (error) return error; } error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); if (error) goto out_dqrele; xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); /* * Change file ownership. Must be the owner or privileged. */ if (mask & (ATTR_UID|ATTR_GID)) { /* * These IDs could have changed since we last looked at them. * But, we're assured that if the ownership did change * while we didn't have the inode locked, inode's dquot(s) * would have changed also. */ iuid = inode->i_uid; igid = inode->i_gid; gid = (mask & ATTR_GID) ? iattr->ia_gid : igid; uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid; /* * Do a quota reservation only if uid/gid is actually * going to change. */ if (XFS_IS_QUOTA_RUNNING(mp) && ((XFS_IS_UQUOTA_ON(mp) && !uid_eq(iuid, uid)) || (XFS_IS_GQUOTA_ON(mp) && !gid_eq(igid, gid)))) { ASSERT(tp); error = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp, NULL, capable(CAP_FOWNER) ? XFS_QMOPT_FORCE_RES : 0); if (error) /* out of quota */ goto out_cancel; } /* * CAP_FSETID overrides the following restrictions: * * The set-user-ID and set-group-ID bits of a file will be * cleared upon successful return from chown() */ if ((inode->i_mode & (S_ISUID|S_ISGID)) && !capable(CAP_FSETID)) inode->i_mode &= ~(S_ISUID|S_ISGID); /* * Change the ownerships and register quota modifications * in the transaction. */ if (!uid_eq(iuid, uid)) { if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_UQUOTA_ON(mp)) { ASSERT(mask & ATTR_UID); ASSERT(udqp); olddquot1 = xfs_qm_vop_chown(tp, ip, &ip->i_udquot, udqp); } inode->i_uid = uid; } if (!gid_eq(igid, gid)) { if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_GQUOTA_ON(mp)) { ASSERT(xfs_sb_version_has_pquotino(&mp->m_sb) || !XFS_IS_PQUOTA_ON(mp)); ASSERT(mask & ATTR_GID); ASSERT(gdqp); olddquot2 = xfs_qm_vop_chown(tp, ip, &ip->i_gdquot, gdqp); } inode->i_gid = gid; } } if (mask & ATTR_MODE) xfs_setattr_mode(ip, iattr); if (mask & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)) xfs_setattr_time(ip, iattr); xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); XFS_STATS_INC(mp, xs_ig_attrchg); if (mp->m_flags & XFS_MOUNT_WSYNC) xfs_trans_set_sync(tp); error = xfs_trans_commit(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); /* * Release any dquot(s) the inode had kept before chown. */ xfs_qm_dqrele(olddquot1); xfs_qm_dqrele(olddquot2); xfs_qm_dqrele(udqp); xfs_qm_dqrele(gdqp); if (error) return error; /* * XXX(hch): Updating the ACL entries is not atomic vs the i_mode * update. We could avoid this with linked transactions * and passing down the transaction pointer all the way * to attr_set. No previous user of the generic * Posix ACL code seems to care about this issue either. */ if ((mask & ATTR_MODE) && !(flags & XFS_ATTR_NOACL)) { error = posix_acl_chmod(inode, inode->i_mode); if (error) return error; } return 0; out_cancel: xfs_trans_cancel(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); out_dqrele: xfs_qm_dqrele(udqp); xfs_qm_dqrele(gdqp); return error; } int xfs_vn_setattr_nonsize( struct dentry *dentry, struct iattr *iattr) { struct xfs_inode *ip = XFS_I(d_inode(dentry)); int error; trace_xfs_setattr(ip); error = xfs_vn_change_ok(dentry, iattr); if (error) return error; return xfs_setattr_nonsize(ip, iattr, 0); } /* * Truncate file. Must have write permission and not be a directory. * * Caution: The caller of this function is responsible for calling * setattr_prepare() or otherwise verifying the change is fine. */ STATIC int xfs_setattr_size( struct xfs_inode *ip, struct iattr *iattr) { struct xfs_mount *mp = ip->i_mount; struct inode *inode = VFS_I(ip); xfs_off_t oldsize, newsize; struct xfs_trans *tp; int error; uint lock_flags = 0; bool did_zeroing = false; ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL)); ASSERT(S_ISREG(inode->i_mode)); ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET| ATTR_MTIME_SET|ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0); oldsize = inode->i_size; newsize = iattr->ia_size; /* * Short circuit the truncate case for zero length files. */ if (newsize == 0 && oldsize == 0 && ip->i_df.if_nextents == 0) { if (!(iattr->ia_valid & (ATTR_CTIME|ATTR_MTIME))) return 0; /* * Use the regular setattr path to update the timestamps. */ iattr->ia_valid &= ~ATTR_SIZE; return xfs_setattr_nonsize(ip, iattr, 0); } /* * Make sure that the dquots are attached to the inode. */ error = xfs_qm_dqattach(ip); if (error) return error; /* * Wait for all direct I/O to complete. */ inode_dio_wait(inode); /* * File data changes must be complete before we start the transaction to * modify the inode. This needs to be done before joining the inode to * the transaction because the inode cannot be unlocked once it is a * part of the transaction. * * Start with zeroing any data beyond EOF that we may expose on file * extension, or zeroing out the rest of the block on a downward * truncate. */ if (newsize > oldsize) { trace_xfs_zero_eof(ip, oldsize, newsize - oldsize); error = iomap_zero_range(inode, oldsize, newsize - oldsize, &did_zeroing, &xfs_buffered_write_iomap_ops); } else { /* * iomap won't detect a dirty page over an unwritten block (or a * cow block over a hole) and subsequently skips zeroing the * newly post-EOF portion of the page. Flush the new EOF to * convert the block before the pagecache truncate. */ error = filemap_write_and_wait_range(inode->i_mapping, newsize, newsize); if (error) return error; error = iomap_truncate_page(inode, newsize, &did_zeroing, &xfs_buffered_write_iomap_ops); } if (error) return error; /* * We've already locked out new page faults, so now we can safely remove * pages from the page cache knowing they won't get refaulted until we * drop the XFS_MMAP_EXCL lock after the extent manipulations are * complete. The truncate_setsize() call also cleans partial EOF page * PTEs on extending truncates and hence ensures sub-page block size * filesystems are correctly handled, too. * * We have to do all the page cache truncate work outside the * transaction context as the "lock" order is page lock->log space * reservation as defined by extent allocation in the writeback path. * Hence a truncate can fail with ENOMEM from xfs_trans_alloc(), but * having already truncated the in-memory version of the file (i.e. made * user visible changes). There's not much we can do about this, except * to hope that the caller sees ENOMEM and retries the truncate * operation. * * And we update in-core i_size and truncate page cache beyond newsize * before writeback the [di_size, newsize] range, so we're guaranteed * not to write stale data past the new EOF on truncate down. */ truncate_setsize(inode, newsize); /* * We are going to log the inode size change in this transaction so * any previous writes that are beyond the on disk EOF and the new * EOF that have not been written out need to be written here. If we * do not write the data out, we expose ourselves to the null files * problem. Note that this includes any block zeroing we did above; * otherwise those blocks may not be zeroed after a crash. */ if (did_zeroing || (newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) { error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, ip->i_d.di_size, newsize - 1); if (error) return error; } error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp); if (error) return error; lock_flags |= XFS_ILOCK_EXCL; xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); /* * Only change the c/mtime if we are changing the size or we are * explicitly asked to change it. This handles the semantic difference * between truncate() and ftruncate() as implemented in the VFS. * * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a * special case where we need to update the times despite not having * these flags set. For all other operations the VFS set these flags * explicitly if it wants a timestamp update. */ if (newsize != oldsize && !(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) { iattr->ia_ctime = iattr->ia_mtime = current_time(inode); iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME; } /* * The first thing we do is set the size to new_size permanently on * disk. This way we don't have to worry about anyone ever being able * to look at the data being freed even in the face of a crash. * What we're getting around here is the case where we free a block, it * is allocated to another file, it is written to, and then we crash. * If the new data gets written to the file but the log buffers * containing the free and reallocation don't, then we'd end up with * garbage in the blocks being freed. As long as we make the new size * permanent before actually freeing any blocks it doesn't matter if * they get written to. */ ip->i_d.di_size = newsize; xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); if (newsize <= oldsize) { error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize); if (error) goto out_trans_cancel; /* * Truncated "down", so we're removing references to old data * here - if we delay flushing for a long time, we expose * ourselves unduly to the notorious NULL files problem. So, * we mark this inode and flush it when the file is closed, * and do not wait the usual (long) time for writeout. */ xfs_iflags_set(ip, XFS_ITRUNCATED); /* A truncate down always removes post-EOF blocks. */ xfs_inode_clear_eofblocks_tag(ip); } if (iattr->ia_valid & ATTR_MODE) xfs_setattr_mode(ip, iattr); if (iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)) xfs_setattr_time(ip, iattr); xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); XFS_STATS_INC(mp, xs_ig_attrchg); if (mp->m_flags & XFS_MOUNT_WSYNC) xfs_trans_set_sync(tp); error = xfs_trans_commit(tp); out_unlock: if (lock_flags) xfs_iunlock(ip, lock_flags); return error; out_trans_cancel: xfs_trans_cancel(tp); goto out_unlock; } int xfs_vn_setattr_size( struct dentry *dentry, struct iattr *iattr) { struct xfs_inode *ip = XFS_I(d_inode(dentry)); int error; trace_xfs_setattr(ip); error = xfs_vn_change_ok(dentry, iattr); if (error) return error; return xfs_setattr_size(ip, iattr); } STATIC int xfs_vn_setattr( struct dentry *dentry, struct iattr *iattr) { int error; if (iattr->ia_valid & ATTR_SIZE) { struct inode *inode = d_inode(dentry); struct xfs_inode *ip = XFS_I(inode); uint iolock; xfs_ilock(ip, XFS_MMAPLOCK_EXCL); iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL; error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP); if (error) { xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); return error; } error = xfs_vn_setattr_size(dentry, iattr); xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); } else { error = xfs_vn_setattr_nonsize(dentry, iattr); } return error; } STATIC int xfs_vn_update_time( struct inode *inode, struct timespec64 *now, int flags) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; int log_flags = XFS_ILOG_TIMESTAMP; struct xfs_trans *tp; int error; trace_xfs_update_time(ip); if (inode->i_sb->s_flags & SB_LAZYTIME) { if (!((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false))) return generic_update_time(inode, now, flags); /* Capture the iversion update that just occurred */ log_flags |= XFS_ILOG_CORE; } error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp); if (error) return error; xfs_ilock(ip, XFS_ILOCK_EXCL); if (flags & S_CTIME) inode->i_ctime = *now; if (flags & S_MTIME) inode->i_mtime = *now; if (flags & S_ATIME) inode->i_atime = *now; xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); xfs_trans_log_inode(tp, ip, log_flags); return xfs_trans_commit(tp); } STATIC int xfs_vn_fiemap( struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 length) { int error; xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED); if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR; error = iomap_fiemap(inode, fieinfo, start, length, &xfs_xattr_iomap_ops); } else { error = iomap_fiemap(inode, fieinfo, start, length, &xfs_read_iomap_ops); } xfs_iunlock(XFS_I(inode), XFS_IOLOCK_SHARED); return error; } STATIC int xfs_vn_tmpfile( struct inode *dir, struct dentry *dentry, umode_t mode) { return xfs_generic_create(dir, dentry, mode, 0, true); } static const struct inode_operations xfs_inode_operations = { .get_acl = xfs_get_acl, .set_acl = xfs_set_acl, .getattr = xfs_vn_getattr, .setattr = xfs_vn_setattr, .listxattr = xfs_vn_listxattr, .fiemap = xfs_vn_fiemap, .update_time = xfs_vn_update_time, }; static const struct inode_operations xfs_dir_inode_operations = { .create = xfs_vn_create, .lookup = xfs_vn_lookup, .link = xfs_vn_link, .unlink = xfs_vn_unlink, .symlink = xfs_vn_symlink, .mkdir = xfs_vn_mkdir, /* * Yes, XFS uses the same method for rmdir and unlink. * * There are some subtile differences deeper in the code, * but we use S_ISDIR to check for those. */ .rmdir = xfs_vn_unlink, .mknod = xfs_vn_mknod, .rename = xfs_vn_rename, .get_acl = xfs_get_acl, .set_acl = xfs_set_acl, .getattr = xfs_vn_getattr, .setattr = xfs_vn_setattr, .listxattr = xfs_vn_listxattr, .update_time = xfs_vn_update_time, .tmpfile = xfs_vn_tmpfile, }; static const struct inode_operations xfs_dir_ci_inode_operations = { .create = xfs_vn_create, .lookup = xfs_vn_ci_lookup, .link = xfs_vn_link, .unlink = xfs_vn_unlink, .symlink = xfs_vn_symlink, .mkdir = xfs_vn_mkdir, /* * Yes, XFS uses the same method for rmdir and unlink. * * There are some subtile differences deeper in the code, * but we use S_ISDIR to check for those. */ .rmdir = xfs_vn_unlink, .mknod = xfs_vn_mknod, .rename = xfs_vn_rename, .get_acl = xfs_get_acl, .set_acl = xfs_set_acl, .getattr = xfs_vn_getattr, .setattr = xfs_vn_setattr, .listxattr = xfs_vn_listxattr, .update_time = xfs_vn_update_time, .tmpfile = xfs_vn_tmpfile, }; static const struct inode_operations xfs_symlink_inode_operations = { .get_link = xfs_vn_get_link, .getattr = xfs_vn_getattr, .setattr = xfs_vn_setattr, .listxattr = xfs_vn_listxattr, .update_time = xfs_vn_update_time, }; static const struct inode_operations xfs_inline_symlink_inode_operations = { .get_link = xfs_vn_get_link_inline, .getattr = xfs_vn_getattr, .setattr = xfs_vn_setattr, .listxattr = xfs_vn_listxattr, .update_time = xfs_vn_update_time, }; /* Figure out if this file actually supports DAX. */ static bool xfs_inode_supports_dax( struct xfs_inode *ip) { struct xfs_mount *mp = ip->i_mount; /* Only supported on regular files. */ if (!S_ISREG(VFS_I(ip)->i_mode)) return false; /* Only supported on non-reflinked files. */ if (xfs_is_reflink_inode(ip)) return false; /* Block size must match page size */ if (mp->m_sb.sb_blocksize != PAGE_SIZE) return false; /* Device has to support DAX too. */ return xfs_inode_buftarg(ip)->bt_daxdev != NULL; } static bool xfs_inode_should_enable_dax( struct xfs_inode *ip) { if (!IS_ENABLED(CONFIG_FS_DAX)) return false; if (ip->i_mount->m_flags & XFS_MOUNT_DAX_NEVER) return false; if (!xfs_inode_supports_dax(ip)) return false; if (ip->i_mount->m_flags & XFS_MOUNT_DAX_ALWAYS) return true; if (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX) return true; return false; } void xfs_diflags_to_iflags( struct xfs_inode *ip, bool init) { struct inode *inode = VFS_I(ip); unsigned int xflags = xfs_ip2xflags(ip); unsigned int flags = 0; ASSERT(!(IS_DAX(inode) && init)); if (xflags & FS_XFLAG_IMMUTABLE) flags |= S_IMMUTABLE; if (xflags & FS_XFLAG_APPEND) flags |= S_APPEND; if (xflags & FS_XFLAG_SYNC) flags |= S_SYNC; if (xflags & FS_XFLAG_NOATIME) flags |= S_NOATIME; if (init && xfs_inode_should_enable_dax(ip)) flags |= S_DAX; /* * S_DAX can only be set during inode initialization and is never set by * the VFS, so we cannot mask off S_DAX in i_flags. */ inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME); inode->i_flags |= flags; } /* * Initialize the Linux inode. * * When reading existing inodes from disk this is called directly from xfs_iget, * when creating a new inode it is called from xfs_ialloc after setting up the * inode. These callers have different criteria for clearing XFS_INEW, so leave * it up to the caller to deal with unlocking the inode appropriately. */ void xfs_setup_inode( struct xfs_inode *ip) { struct inode *inode = &ip->i_vnode; gfp_t gfp_mask; inode->i_ino = ip->i_ino; inode->i_state = I_NEW; inode_sb_list_add(inode); /* make the inode look hashed for the writeback code */ inode_fake_hash(inode); i_size_write(inode, ip->i_d.di_size); xfs_diflags_to_iflags(ip, true); if (S_ISDIR(inode->i_mode)) { /* * We set the i_rwsem class here to avoid potential races with * lockdep_annotate_inode_mutex_key() reinitialising the lock * after a filehandle lookup has already found the inode in * cache before it has been unlocked via unlock_new_inode(). */ lockdep_set_class(&inode->i_rwsem, &inode->i_sb->s_type->i_mutex_dir_key); lockdep_set_class(&ip->i_lock.mr_lock, &xfs_dir_ilock_class); } else { lockdep_set_class(&ip->i_lock.mr_lock, &xfs_nondir_ilock_class); } /* * Ensure all page cache allocations are done from GFP_NOFS context to * prevent direct reclaim recursion back into the filesystem and blowing * stacks or deadlocking. */ gfp_mask = mapping_gfp_mask(inode->i_mapping); mapping_set_gfp_mask(inode->i_mapping, (gfp_mask & ~(__GFP_FS))); /* * If there is no attribute fork no ACL can exist on this inode, * and it can't have any file capabilities attached to it either. */ if (!XFS_IFORK_Q(ip)) { inode_has_no_xattr(inode); cache_no_acl(inode); } } void xfs_setup_iops( struct xfs_inode *ip) { struct inode *inode = &ip->i_vnode; switch (inode->i_mode & S_IFMT) { case S_IFREG: inode->i_op = &xfs_inode_operations; inode->i_fop = &xfs_file_operations; if (IS_DAX(inode)) inode->i_mapping->a_ops = &xfs_dax_aops; else inode->i_mapping->a_ops = &xfs_address_space_operations; break; case S_IFDIR: if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb)) inode->i_op = &xfs_dir_ci_inode_operations; else inode->i_op = &xfs_dir_inode_operations; inode->i_fop = &xfs_dir_file_operations; break; case S_IFLNK: if (ip->i_df.if_flags & XFS_IFINLINE) inode->i_op = &xfs_inline_symlink_inode_operations; else inode->i_op = &xfs_symlink_inode_operations; break; default: inode->i_op = &xfs_inode_operations; init_special_inode(inode, inode->i_mode, inode->i_rdev); break; } }