diff options
Diffstat (limited to 'fs/xfs/xfs_iops.c')
| -rw-r--r-- | fs/xfs/xfs_iops.c | 1334 |
1 files changed, 1334 insertions, 0 deletions
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c new file mode 100644 index 000000000..2e10e1c66 --- /dev/null +++ b/fs/xfs/xfs_iops.c @@ -0,0 +1,1334 @@ +// 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_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 <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); + 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 user_namespace *mnt_userns, + struct inode *dir, + struct dentry *dentry, + umode_t mode, + dev_t rdev, + struct file *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(mnt_userns, XFS_I(dir), &name, mode, rdev, + xfs_create_need_xattr(dir, default_acl, acl), + &ip); + } else { + error = xfs_create_tmpfile(mnt_userns, XFS_I(dir), mode, &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 user_namespace *mnt_userns, + struct inode *dir, + struct dentry *dentry, + umode_t mode, + dev_t rdev) +{ + return xfs_generic_create(mnt_userns, dir, dentry, mode, rdev, NULL); +} + +STATIC int +xfs_vn_create( + struct user_namespace *mnt_userns, + struct inode *dir, + struct dentry *dentry, + umode_t mode, + bool flags) +{ + return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, NULL); +} + +STATIC int +xfs_vn_mkdir( + struct user_namespace *mnt_userns, + struct inode *dir, + struct dentry *dentry, + umode_t mode) +{ + return xfs_generic_create(mnt_userns, 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); + 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_has_asciici(XFS_M(dir->i_sb))) + d_invalidate(dentry); + return 0; +} + +STATIC int +xfs_vn_symlink( + struct user_namespace *mnt_userns, + 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(mnt_userns, 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 user_namespace *mnt_userns, + 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(mnt_userns, 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)); + + /* + * 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 PAGE_SIZE; +} + +STATIC int +xfs_vn_getattr( + struct user_namespace *mnt_userns, + 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(mnt_userns, inode); + vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, 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->i_atime; + stat->mtime = inode->i_mtime; + stat->ctime = inode->i_ctime; + 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; + } + } + + /* + * 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 user_namespace *mnt_userns, + 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(mnt_userns, 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 user_namespace *mnt_userns, + 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(mnt_userns, 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(mnt_userns, 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(mnt_userns, 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(mnt_userns, 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(mnt_userns, 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(mnt_userns, inode, 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 user_namespace *mnt_userns, + 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_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(mnt_userns, 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 { + /* + * 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 = 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; + } + + 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_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(mnt_userns, 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 user_namespace *mnt_userns, + 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(mnt_userns, dentry, iattr); + if (error) + return error; + return xfs_setattr_size(mnt_userns, ip, iattr); +} + +STATIC int +xfs_vn_setattr( + struct user_namespace *mnt_userns, + 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(mnt_userns, dentry, iattr); + xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); + } else { + trace_xfs_setattr(ip); + + error = xfs_vn_change_ok(mnt_userns, dentry, iattr); + if (!error) + error = xfs_setattr_nonsize(mnt_userns, ip, 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 user_namespace *mnt_userns, + struct inode *dir, + struct file *file, + umode_t mode) +{ + int err = xfs_generic_create(mnt_userns, dir, file->f_path.dentry, mode, 0, file); + + return finish_open_simple(file, err); +} + +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, + .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_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_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; + + /* 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 (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.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_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; + } +} |