// 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_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_attr.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
#include "xfs_bmap_btree.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 "xfs_ioctl.h"
#include "xfs_xattr.h"
#include "xfs_file.h"
#include "xfs_bmap.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_change(&args, XFS_ATTRUPDATE_UPSERT);
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).
*/
int
xfs_inode_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_inode_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));
}
/*
* Check to see if we are likely to need an extended attribute to be added to
* the inode we are about to allocate. This allows the attribute fork to be
* created during the inode allocation, reducing the number of transactions we
* need to do in this fast path.
*
* The security checks are optimistic, but not guaranteed. The two LSMs that
* require xattrs to be added here (selinux and smack) are also the only two
* LSMs that add a sb->s_security structure to the superblock. Hence if security
* is enabled and sb->s_security is set, we have a pretty good idea that we are
* going to be asked to add a security xattr immediately after allocating the
* xfs inode and instantiating the VFS inode.
*/
static inline bool
xfs_create_need_xattr(
struct inode *dir,
struct posix_acl *default_acl,
struct posix_acl *acl)
{
if (acl)
return true;
if (default_acl)
return true;
#if IS_ENABLED(CONFIG_SECURITY)
if (dir->i_sb->s_security)
return true;
#endif
return false;
}
STATIC int
xfs_generic_create(
struct mnt_idmap *idmap,
struct inode *dir,
struct dentry *dentry,
umode_t mode,
dev_t rdev,
struct file *tmpfile) /* unnamed file */
{
struct xfs_icreate_args args = {
.idmap = idmap,
.pip = XFS_I(dir),
.rdev = rdev,
.mode = mode,
};
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(args.mode) || S_ISBLK(args.mode)) {
if (unlikely(!sysv_valid_dev(args.rdev) ||
MAJOR(args.rdev) & ~0x1ff))
return -EINVAL;
} else {
args.rdev = 0;
}
error = posix_acl_create(dir, &args.mode, &default_acl, &acl);
if (error)
return error;
/* Verify mode is valid also for tmpfile case */
error = xfs_dentry_mode_to_name(&name, dentry, args.mode);
if (unlikely(error))
goto out_free_acl;
if (!tmpfile) {
if (xfs_create_need_xattr(dir, default_acl, acl))
args.flags |= XFS_ICREATE_INIT_XATTRS;
error = xfs_create(&args, &name, &ip);
} else {
args.flags |= XFS_ICREATE_TMPFILE;
/*
* If this temporary file will not be linkable, don't bother
* creating an attr fork to receive a parent pointer.
*/
if (tmpfile->f_flags & O_EXCL)
args.flags |= XFS_ICREATE_UNLINKABLE;
error = xfs_create_tmpfile(&args, &ip);
}
if (unlikely(error))
goto out_free_acl;
inode = VFS_I(ip);
error = xfs_inode_init_security(inode, dir, &dentry->d_name);
if (unlikely(error))
goto out_cleanup_inode;
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;
}
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(tmpfile, inode);
} else
d_instantiate(dentry, inode);
xfs_finish_inode_setup(ip);
out_free_acl:
posix_acl_release(default_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 mnt_idmap *idmap,
struct inode *dir,
struct dentry *dentry,
umode_t mode,
dev_t rdev)
{
return xfs_generic_create(idmap, dir, dentry, mode, rdev, NULL);
}
STATIC int
xfs_vn_create(
struct mnt_idmap *idmap,
struct inode *dir,
struct dentry *dentry,
umode_t mode,
bool flags)
{
return xfs_generic_create(idmap, dir, dentry, mode, 0, NULL);
}
STATIC int
xfs_vn_mkdir(
struct mnt_idmap *idmap,
struct inode *dir,
struct dentry *dentry,
umode_t mode)
{
return xfs_generic_create(idmap, dir, dentry, mode | S_IFDIR, 0, NULL);
}
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);
kfree(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;
if (IS_PRIVATE(inode))
return -EPERM;
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_has_asciici(XFS_M(dir->i_sb)))
d_invalidate(dentry);
return 0;
}
STATIC int
xfs_vn_symlink(
struct mnt_idmap *idmap,
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(idmap, XFS_I(dir), &name, symname, mode, &cip);
if (unlikely(error))
goto out;
inode = VFS_I(cip);
error = xfs_inode_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 mnt_idmap *idmap,
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(idmap, 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 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_FSB_TO_B(mp, xfs_get_extsz_hint(ip) ? : 1);
/*
* 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 (xfs_has_large_iosize(mp)) {
if (mp->m_swidth)
return XFS_FSB_TO_B(mp, mp->m_swidth);
if (xfs_has_allocsize(mp))
return 1U << mp->m_allocsize_log;
}
return max_t(uint32_t, PAGE_SIZE, mp->m_sb.sb_blocksize);
}
STATIC int
xfs_vn_getattr(
struct mnt_idmap *idmap,
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;
vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
trace_xfs_getattr(ip);
if (xfs_is_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 = vfsuid_into_kuid(vfsuid);
stat->gid = vfsgid_into_kgid(vfsgid);
stat->ino = ip->i_ino;
stat->atime = inode_get_atime(inode);
stat->mtime = inode_get_mtime(inode);
stat->ctime = inode_get_ctime(inode);
stat->blocks = XFS_FSB_TO_BB(mp, ip->i_nblocks + ip->i_delayed_blks);
if (xfs_has_v3inodes(mp)) {
if (request_mask & STATX_BTIME) {
stat->result_mask |= STATX_BTIME;
stat->btime = ip->i_crtime;
}
}
if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
stat->change_cookie = inode_query_iversion(inode);
stat->result_mask |= STATX_CHANGE_COOKIE;
}
/*
* Note: If you add another clause to set an attribute flag, please
* update attributes_mask below.
*/
if (ip->i_diflags & XFS_DIFLAG_IMMUTABLE)
stat->attributes |= STATX_ATTR_IMMUTABLE;
if (ip->i_diflags & XFS_DIFLAG_APPEND)
stat->attributes |= STATX_ATTR_APPEND;
if (ip->i_diflags & 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;
case S_IFREG:
if (request_mask & STATX_DIOALIGN) {
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
struct block_device *bdev = target->bt_bdev;
stat->result_mask |= STATX_DIOALIGN;
stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
stat->dio_offset_align = bdev_logical_block_size(bdev);
}
fallthrough;
default:
stat->blksize = xfs_stat_blksize(ip);
stat->rdev = 0;
break;
}
return 0;
}
static int
xfs_vn_change_ok(
struct mnt_idmap *idmap,
struct dentry *dentry,
struct iattr *iattr)
{
struct xfs_mount *mp = XFS_I(d_inode(dentry))->i_mount;
if (xfs_is_readonly(mp))
return -EROFS;
if (xfs_is_shutdown(mp))
return -EIO;
return setattr_prepare(idmap, 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.
*/
static int
xfs_setattr_nonsize(
struct mnt_idmap *idmap,
struct dentry *dentry,
struct xfs_inode *ip,
struct iattr *iattr)
{
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;
kgid_t gid = GLOBAL_ROOT_GID;
struct xfs_dquot *udqp = NULL, *gdqp = NULL;
struct xfs_dquot *old_udqp = NULL, *old_gdqp = 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 = from_vfsuid(idmap, i_user_ns(inode),
iattr->ia_vfsuid);
qflags |= XFS_QMOPT_UQUOTA;
} else {
uid = inode->i_uid;
}
if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
gid = from_vfsgid(idmap, i_user_ns(inode),
iattr->ia_vfsgid);
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_projid,
qflags, &udqp, &gdqp, NULL);
if (error)
return error;
}
error = xfs_trans_alloc_ichange(ip, udqp, gdqp, NULL,
has_capability_noaudit(current, CAP_FOWNER), &tp);
if (error)
goto out_dqrele;
/*
* Register quota modifications in the transaction. Must be the owner
* or privileged. 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.
*/
if (XFS_IS_UQUOTA_ON(mp) &&
i_uid_needs_update(idmap, iattr, inode)) {
ASSERT(udqp);
old_udqp = xfs_qm_vop_chown(tp, ip, &ip->i_udquot, udqp);
}
if (XFS_IS_GQUOTA_ON(mp) &&
i_gid_needs_update(idmap, iattr, inode)) {
ASSERT(xfs_has_pquotino(mp) || !XFS_IS_PQUOTA_ON(mp));
ASSERT(gdqp);
old_gdqp = xfs_qm_vop_chown(tp, ip, &ip->i_gdquot, gdqp);
}
setattr_copy(idmap, inode, iattr);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
XFS_STATS_INC(mp, xs_ig_attrchg);
if (xfs_has_wsync(mp))
xfs_trans_set_sync(tp);
error = xfs_trans_commit(tp);
/*
* Release any dquot(s) the inode had kept before chown.
*/
xfs_qm_dqrele(old_udqp);
xfs_qm_dqrele(old_gdqp);
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) {
error = posix_acl_chmod(idmap, dentry, inode->i_mode);
if (error)
return error;
}
return 0;
out_dqrele:
xfs_qm_dqrele(udqp);
xfs_qm_dqrele(gdqp);
return error;
}
/*
* 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 mnt_idmap *idmap,
struct dentry *dentry,
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;
uint resblks = 0;
bool did_zeroing = false;
xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | 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_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(idmap, dentry, ip, iattr);
}
/*
* 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 = xfs_zero_range(ip, oldsize, newsize - oldsize,
&did_zeroing);
} else {
error = xfs_truncate_page(ip, newsize, &did_zeroing);
}
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 [i_disk_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_disk_size && oldsize != ip->i_disk_size)) {
error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
ip->i_disk_size, newsize - 1);
if (error)
return error;
}
/*
* For realtime inode with more than one block rtextsize, we need the
* block reservation for bmap btree block allocations/splits that can
* happen since it could split the tail written extent and convert the
* right beyond EOF one to unwritten.
*/
if (xfs_inode_has_bigrtalloc(ip))
resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, resblks,
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_disk_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);
}
ASSERT(!(iattr->ia_valid & (ATTR_UID | ATTR_GID)));
setattr_copy(idmap, inode, iattr);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
XFS_STATS_INC(mp, xs_ig_attrchg);
if (xfs_has_wsync(mp))
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 mnt_idmap *idmap,
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(idmap, dentry, iattr);
if (error)
return error;
return xfs_setattr_size(idmap, dentry, ip, iattr);
}
STATIC int
xfs_vn_setattr(
struct mnt_idmap *idmap,
struct dentry *dentry,
struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
struct xfs_inode *ip = XFS_I(inode);
int error;
if (iattr->ia_valid & ATTR_SIZE) {
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(idmap, dentry, iattr);
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
} else {
trace_xfs_setattr(ip);
error = xfs_vn_change_ok(idmap, dentry, iattr);
if (!error)
error = xfs_setattr_nonsize(idmap, dentry, ip, iattr);
}
return error;
}
STATIC int
xfs_vn_update_time(
struct inode *inode,
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;
struct timespec64 now;
trace_xfs_update_time(ip);
if (inode->i_sb->s_flags & SB_LAZYTIME) {
if (!((flags & S_VERSION) &&
inode_maybe_inc_iversion(inode, false))) {
generic_update_time(inode, flags);
return 0;
}
/* 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|S_MTIME))
now = inode_set_ctime_current(inode);
else
now = current_time(inode);
if (flags & S_MTIME)
inode_set_mtime_to_ts(inode, now);
if (flags & S_ATIME)
inode_set_atime_to_ts(inode, 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 mnt_idmap *idmap,
struct inode *dir,
struct file *file,
umode_t mode)
{
int err = xfs_generic_create(idmap, dir, file->f_path.dentry, mode, 0, file);
return finish_open_simple(file, err);
}
static const struct inode_operations xfs_inode_operations = {
.get_inode_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,
.fileattr_get = xfs_fileattr_get,
.fileattr_set = xfs_fileattr_set,
};
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_inode_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,
.fileattr_get = xfs_fileattr_get,
.fileattr_set = xfs_fileattr_set,
};
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_inode_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,
.fileattr_get = xfs_fileattr_get,
.fileattr_set = xfs_fileattr_set,
};
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,
};
/* 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;
/* 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 (xfs_has_dax_never(ip->i_mount))
return false;
if (!xfs_inode_supports_dax(ip))
return false;
if (xfs_has_dax_always(ip->i_mount))
return true;
if (ip->i_diflags2 & 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_init_new_inode 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_disk_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, &xfs_dir_ilock_class);
} else {
lockdep_set_class(&ip->i_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)));
/*
* For real-time inodes update the stable write flags to that of the RT
* device instead of the data device.
*/
if (S_ISREG(inode->i_mode) && XFS_IS_REALTIME_INODE(ip))
xfs_update_stable_writes(ip);
/*
* 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_inode_has_attr_fork(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_has_asciici(XFS_M(inode->i_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:
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;
}
}
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