WSL2-Linux-Kernel/fs/jfs/file.c

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C
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) International Business Machines Corp., 2000-2002
* Portions Copyright (C) Christoph Hellwig, 2001-2002
*/
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/posix_acl.h>
#include <linux/quotaops.h>
#include "jfs_incore.h"
#include "jfs_inode.h"
#include "jfs_dmap.h"
#include "jfs_txnmgr.h"
#include "jfs_xattr.h"
#include "jfs_acl.h"
#include "jfs_debug.h"
int jfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file->f_mapping->host;
int rc = 0;
rc = file_write_and_wait_range(file, start, end);
if (rc)
return rc;
inode_lock(inode);
if (!(inode->i_state & I_DIRTY_ALL) ||
(datasync && !(inode->i_state & I_DIRTY_DATASYNC))) {
/* Make sure committed changes hit the disk */
jfs_flush_journal(JFS_SBI(inode->i_sb)->log, 1);
inode_unlock(inode);
return rc;
}
rc |= jfs_commit_inode(inode, 1);
inode_unlock(inode);
return rc ? -EIO : 0;
}
static int jfs_open(struct inode *inode, struct file *file)
{
int rc;
if ((rc = dquot_file_open(inode, file)))
return rc;
/*
* We attempt to allow only one "active" file open per aggregate
* group. Otherwise, appending to files in parallel can cause
* fragmentation within the files.
*
* If the file is empty, it was probably just created and going
* to be written to. If it has a size, we'll hold off until the
* file is actually grown.
*/
if (S_ISREG(inode->i_mode) && file->f_mode & FMODE_WRITE &&
(inode->i_size == 0)) {
struct jfs_inode_info *ji = JFS_IP(inode);
spin_lock_irq(&ji->ag_lock);
if (ji->active_ag == -1) {
struct jfs_sb_info *jfs_sb = JFS_SBI(inode->i_sb);
ji->active_ag = BLKTOAG(addressPXD(&ji->ixpxd), jfs_sb);
atomic_inc(&jfs_sb->bmap->db_active[ji->active_ag]);
}
spin_unlock_irq(&ji->ag_lock);
}
return 0;
}
static int jfs_release(struct inode *inode, struct file *file)
{
struct jfs_inode_info *ji = JFS_IP(inode);
spin_lock_irq(&ji->ag_lock);
if (ji->active_ag != -1) {
struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
atomic_dec(&bmap->db_active[ji->active_ag]);
ji->active_ag = -1;
}
spin_unlock_irq(&ji->ag_lock);
return 0;
}
int jfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
int rc;
rc = setattr_prepare(&init_user_ns, dentry, iattr);
if (rc)
return rc;
if (is_quota_modification(inode, iattr)) {
rc = dquot_initialize(inode);
if (rc)
return rc;
}
if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) ||
(iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) {
rc = dquot_transfer(inode, iattr);
if (rc)
return rc;
}
if ((iattr->ia_valid & ATTR_SIZE) &&
iattr->ia_size != i_size_read(inode)) {
inode_dio_wait(inode);
rc = inode_newsize_ok(inode, iattr->ia_size);
if (rc)
return rc;
truncate_setsize(inode, iattr->ia_size);
jfs_truncate(inode);
}
setattr_copy(&init_user_ns, inode, iattr);
mark_inode_dirty(inode);
if (iattr->ia_valid & ATTR_MODE)
acl: handle idmapped mounts The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-21 16:19:27 +03:00
rc = posix_acl_chmod(&init_user_ns, inode, inode->i_mode);
return rc;
}
const struct inode_operations jfs_file_inode_operations = {
.listxattr = jfs_listxattr,
.setattr = jfs_setattr,
.fileattr_get = jfs_fileattr_get,
.fileattr_set = jfs_fileattr_set,
#ifdef CONFIG_JFS_POSIX_ACL
.get_acl = jfs_get_acl,
.set_acl = jfs_set_acl,
#endif
};
const struct file_operations jfs_file_operations = {
.open = jfs_open,
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.mmap = generic_file_mmap,
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
.fsync = jfs_fsync,
.release = jfs_release,
.unlocked_ioctl = jfs_ioctl,
.compat_ioctl = compat_ptr_ioctl,
};