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Diffstat (limited to '')
| -rw-r--r-- | fs/xfs/xfs_iops.c | 1370 |
1 files changed, 1370 insertions, 0 deletions
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c new file mode 100644 index 000000000..6011086b5 --- /dev/null +++ b/fs/xfs/xfs_iops.c @@ -0,0 +1,1370 @@ +// 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_da_format.h" +#include "xfs_inode.h" +#include "xfs_bmap.h" +#include "xfs_bmap_util.h" +#include "xfs_acl.h" +#include "xfs_quota.h" +#include "xfs_error.h" +#include "xfs_attr.h" +#include "xfs_trans.h" +#include "xfs_trace.h" +#include "xfs_icache.h" +#include "xfs_symlink.h" +#include "xfs_da_btree.h" +#include "xfs_dir2.h" +#include "xfs_trans_space.h" +#include "xfs_iomap.h" +#include "xfs_defer.h" + +#include <linux/capability.h> +#include <linux/xattr.h> +#include <linux/posix_acl.h> +#include <linux/security.h> +#include <linux/iomap.h> +#include <linux/slab.h> +#include <linux/iversion.h> + +/* + * Directories have different lock order w.r.t. mmap_sem 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_sem 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++) { + error = xfs_attr_set(ip, xattr->name, xattr->value, + xattr->value_len, ATTR_SECURE); + 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_vn_mknod(dir, dentry, mode, 0); +} + +STATIC int +xfs_vn_mkdir( + struct inode *dir, + struct dentry *dentry, + umode_t mode) +{ + return xfs_vn_mknod(dir, dentry, mode|S_IFDIR, 0); +} + +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) +{ + char *link; + + ASSERT(XFS_I(inode)->i_df.if_flags & XFS_IFINLINE); + + /* + * The VFS crashes on a NULL pointer, so return -EFSCORRUPTED if + * if_data is junk. + */ + link = XFS_I(inode)->i_df.if_u1.if_data; + if (!link) + return ERR_PTR(-EFSCORRUPTED); + return link; +} + +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 (ip->i_d.di_version == 3) { + if (request_mask & STATX_BTIME) { + stat->result_mask |= STATX_BTIME; + stat->btime.tv_sec = ip->i_d.di_crtime.t_sec; + stat->btime.tv_nsec = ip->i_d.di_crtime.t_nsec; + } + } + + /* + * 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: + if (XFS_IS_REALTIME_INODE(ip)) { + /* + * If the file blocks are being allocated from a + * realtime volume, then return the inode's realtime + * extent size or the realtime volume's extent size. + */ + stat->blksize = + xfs_get_extsz_hint(ip) << mp->m_sb.sb_blocklog; + } else + stat->blksize = xfs_preferred_iosize(mp); + 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, xfs_kuid_to_uid(uid), + xfs_kgid_to_gid(gid), + xfs_get_projid(ip), + 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; + } + } + + /* + * Change file ownership. Must be the owner or privileged. + */ + if (mask & (ATTR_UID|ATTR_GID)) { + /* + * 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); + } + ip->i_d.di_uid = xfs_kuid_to_uid(uid); + 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); + } + ip->i_d.di_gid = xfs_kgid_to_gid(gid); + 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_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_d.di_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_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_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_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 non-reflinked files. */ + if (!S_ISREG(VFS_I(ip)->i_mode) || xfs_is_reflink_inode(ip)) + return false; + + /* DAX mount option or DAX iflag must be set. */ + if (!(mp->m_flags & XFS_MOUNT_DAX) && + !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)) + 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_find_daxdev_for_inode(VFS_I(ip)) != NULL; +} + +STATIC void +xfs_diflags_to_iflags( + struct inode *inode, + struct xfs_inode *ip) +{ + uint16_t flags = ip->i_d.di_flags; + + inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | + S_NOATIME | S_DAX); + + if (flags & XFS_DIFLAG_IMMUTABLE) + inode->i_flags |= S_IMMUTABLE; + if (flags & XFS_DIFLAG_APPEND) + inode->i_flags |= S_APPEND; + if (flags & XFS_DIFLAG_SYNC) + inode->i_flags |= S_SYNC; + if (flags & XFS_DIFLAG_NOATIME) + inode->i_flags |= S_NOATIME; + if (xfs_inode_supports_dax(ip)) + inode->i_flags |= S_DAX; +} + +/* + * 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); + + inode->i_uid = xfs_uid_to_kuid(ip->i_d.di_uid); + inode->i_gid = xfs_gid_to_kgid(ip->i_d.di_gid); + + i_size_write(inode, ip->i_d.di_size); + xfs_diflags_to_iflags(inode, ip); + + 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); + ip->d_ops = ip->i_mount->m_dir_inode_ops; + } else { + ip->d_ops = ip->i_mount->m_nondir_inode_ops; + 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; + } +} |