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-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZZU0CgAKCRCRxhvAZXjc osncAQDSJK0frJL+72NqXxa4YNzivrnuw6fhp5iaDAEqxdm8ygEAoJWyh7Rmkt8G drAXWGyGnCYqv7UgC6axLyciid7TxQg= =vJuv -----END PGP SIGNATURE----- Merge tag 'vfs-6.8.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs mount updates from Christian Brauner: "This contains the work to retrieve detailed information about mounts via two new system calls. This is hopefully the beginning of the end of the saga that started with fsinfo() years ago. The LWN articles in [1] and [2] can serve as a summary so we can avoid rehashing everything here. At LSFMM in May 2022 we got into a room and agreed on what we want to do about fsinfo(). Basically, split it into pieces. This is the first part of that agreement. Specifically, it is concerned with retrieving information about mounts. So this only concerns the mount information retrieval, not the mount table change notification, or the extended filesystem specific mount option work. That is separate work. Currently mounts have a 32bit id. Mount ids are already in heavy use by libmount and other low-level userspace but they can't be relied upon because they're recycled very quickly. We agreed that mounts should carry a unique 64bit id by which they can be referenced directly. This is now implemented as part of this work. The new 64bit mount id is exposed in statx() through the new STATX_MNT_ID_UNIQUE flag. If the flag isn't raised the old mount id is returned. If it is raised and the kernel supports the new 64bit mount id the flag is raised in the result mask and the new 64bit mount id is returned. New and old mount ids do not overlap so they cannot be conflated. Two new system calls are introduced that operate on the 64bit mount id: statmount() and listmount(). A summary of the api and usage can be found on LWN as well (cf. [3]) but of course, I'll provide a summary here as well. Both system calls rely on struct mnt_id_req. Which is the request struct used to pass the 64bit mount id identifying the mount to operate on. It is extensible to allow for the addition of new parameters and for future use in other apis that make use of mount ids. statmount() mimicks the semantics of statx() and exposes a set flags that userspace may raise in mnt_id_req to request specific information to be retrieved. A statmount() call returns a struct statmount filled in with information about the requested mount. Supported requests are indicated by raising the request flag passed in struct mnt_id_req in the @mask argument in struct statmount. Currently we do support: - STATMOUNT_SB_BASIC: Basic filesystem info - STATMOUNT_MNT_BASIC Mount information (mount id, parent mount id, mount attributes etc) - STATMOUNT_PROPAGATE_FROM Propagation from what mount in current namespace - STATMOUNT_MNT_ROOT Path of the root of the mount (e.g., mount --bind /bla /mnt returns /bla) - STATMOUNT_MNT_POINT Path of the mount point (e.g., mount --bind /bla /mnt returns /mnt) - STATMOUNT_FS_TYPE Name of the filesystem type as the magic number isn't enough due to submounts The string options STATMOUNT_MNT_{ROOT,POINT} and STATMOUNT_FS_TYPE are appended to the end of the struct. Userspace can use the offsets in @fs_type, @mnt_root, and @mnt_point to reference those strings easily. The struct statmount reserves quite a bit of space currently for future extensibility. This isn't really a problem and if this bothers us we can just send a follow-up pull request during this cycle. listmount() is given a 64bit mount id via mnt_id_req just as statmount(). It takes a buffer and a size to return an array of the 64bit ids of the child mounts of the requested mount. Userspace can thus choose to either retrieve child mounts for a mount in batches or iterate through the child mounts. For most use-cases it will be sufficient to just leave space for a few child mounts. But for big mount tables having an iterator is really helpful. Iterating through a mount table works by setting @param in mnt_id_req to the mount id of the last child mount retrieved in the previous listmount() call" Link: https://lwn.net/Articles/934469 [1] Link: https://lwn.net/Articles/829212 [2] Link: https://lwn.net/Articles/950569 [3] * tag 'vfs-6.8.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: add selftest for statmount/listmount fs: keep struct mnt_id_req extensible wire up syscalls for statmount/listmount add listmount(2) syscall statmount: simplify string option retrieval statmount: simplify numeric option retrieval add statmount(2) syscall namespace: extract show_path() helper mounts: keep list of mounts in an rbtree add unique mount ID
866 lines
23 KiB
C
866 lines
23 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/stat.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/blkdev.h>
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#include <linux/export.h>
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#include <linux/mm.h>
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#include <linux/errno.h>
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#include <linux/file.h>
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#include <linux/highuid.h>
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include <linux/security.h>
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#include <linux/cred.h>
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#include <linux/syscalls.h>
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#include <linux/pagemap.h>
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#include <linux/compat.h>
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#include <linux/iversion.h>
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#include <linux/uaccess.h>
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#include <asm/unistd.h>
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#include "internal.h"
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#include "mount.h"
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/**
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* generic_fillattr - Fill in the basic attributes from the inode struct
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* @idmap: idmap of the mount the inode was found from
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* @request_mask: statx request_mask
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* @inode: Inode to use as the source
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* @stat: Where to fill in the attributes
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*
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* Fill in the basic attributes in the kstat structure from data that's to be
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* found on the VFS inode structure. This is the default if no getattr inode
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* operation is supplied.
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*
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* If the inode has been found through an idmapped mount the idmap of
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* the vfsmount must be passed through @idmap. This function will then
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* take care to map the inode according to @idmap before filling in the
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* uid and gid filds. On non-idmapped mounts or if permission checking is to be
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* performed on the raw inode simply pass @nop_mnt_idmap.
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*/
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void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,
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struct inode *inode, struct kstat *stat)
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{
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vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
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vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
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stat->dev = inode->i_sb->s_dev;
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stat->ino = inode->i_ino;
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stat->mode = inode->i_mode;
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stat->nlink = inode->i_nlink;
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stat->uid = vfsuid_into_kuid(vfsuid);
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stat->gid = vfsgid_into_kgid(vfsgid);
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stat->rdev = inode->i_rdev;
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stat->size = i_size_read(inode);
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stat->atime = inode_get_atime(inode);
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stat->mtime = inode_get_mtime(inode);
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stat->ctime = inode_get_ctime(inode);
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stat->blksize = i_blocksize(inode);
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stat->blocks = inode->i_blocks;
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if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
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stat->result_mask |= STATX_CHANGE_COOKIE;
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stat->change_cookie = inode_query_iversion(inode);
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}
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}
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EXPORT_SYMBOL(generic_fillattr);
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/**
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* generic_fill_statx_attr - Fill in the statx attributes from the inode flags
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* @inode: Inode to use as the source
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* @stat: Where to fill in the attribute flags
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*
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* Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
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* inode that are published on i_flags and enforced by the VFS.
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*/
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void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
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{
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if (inode->i_flags & S_IMMUTABLE)
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stat->attributes |= STATX_ATTR_IMMUTABLE;
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if (inode->i_flags & S_APPEND)
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stat->attributes |= STATX_ATTR_APPEND;
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stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
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}
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EXPORT_SYMBOL(generic_fill_statx_attr);
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/**
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* vfs_getattr_nosec - getattr without security checks
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* @path: file to get attributes from
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* @stat: structure to return attributes in
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* @request_mask: STATX_xxx flags indicating what the caller wants
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* @query_flags: Query mode (AT_STATX_SYNC_TYPE)
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*
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* Get attributes without calling security_inode_getattr.
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*
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* Currently the only caller other than vfs_getattr is internal to the
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* filehandle lookup code, which uses only the inode number and returns no
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* attributes to any user. Any other code probably wants vfs_getattr.
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*/
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int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
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u32 request_mask, unsigned int query_flags)
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{
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struct mnt_idmap *idmap;
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struct inode *inode = d_backing_inode(path->dentry);
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memset(stat, 0, sizeof(*stat));
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stat->result_mask |= STATX_BASIC_STATS;
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query_flags &= AT_STATX_SYNC_TYPE;
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/* allow the fs to override these if it really wants to */
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/* SB_NOATIME means filesystem supplies dummy atime value */
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if (inode->i_sb->s_flags & SB_NOATIME)
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stat->result_mask &= ~STATX_ATIME;
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/*
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* Note: If you add another clause to set an attribute flag, please
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* update attributes_mask below.
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*/
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if (IS_AUTOMOUNT(inode))
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stat->attributes |= STATX_ATTR_AUTOMOUNT;
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if (IS_DAX(inode))
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stat->attributes |= STATX_ATTR_DAX;
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stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
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STATX_ATTR_DAX);
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idmap = mnt_idmap(path->mnt);
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if (inode->i_op->getattr)
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return inode->i_op->getattr(idmap, path, stat,
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request_mask,
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query_flags | AT_GETATTR_NOSEC);
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generic_fillattr(idmap, request_mask, inode, stat);
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return 0;
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}
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EXPORT_SYMBOL(vfs_getattr_nosec);
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/*
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* vfs_getattr - Get the enhanced basic attributes of a file
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* @path: The file of interest
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* @stat: Where to return the statistics
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* @request_mask: STATX_xxx flags indicating what the caller wants
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* @query_flags: Query mode (AT_STATX_SYNC_TYPE)
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*
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* Ask the filesystem for a file's attributes. The caller must indicate in
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* request_mask and query_flags to indicate what they want.
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*
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* If the file is remote, the filesystem can be forced to update the attributes
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* from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
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* suppress the update by passing AT_STATX_DONT_SYNC.
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*
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* Bits must have been set in request_mask to indicate which attributes the
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* caller wants retrieving. Any such attribute not requested may be returned
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* anyway, but the value may be approximate, and, if remote, may not have been
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* synchronised with the server.
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*
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* 0 will be returned on success, and a -ve error code if unsuccessful.
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*/
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int vfs_getattr(const struct path *path, struct kstat *stat,
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u32 request_mask, unsigned int query_flags)
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{
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int retval;
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if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC))
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return -EPERM;
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retval = security_inode_getattr(path);
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if (retval)
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return retval;
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return vfs_getattr_nosec(path, stat, request_mask, query_flags);
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}
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EXPORT_SYMBOL(vfs_getattr);
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/**
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* vfs_fstat - Get the basic attributes by file descriptor
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* @fd: The file descriptor referring to the file of interest
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* @stat: The result structure to fill in.
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*
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* This function is a wrapper around vfs_getattr(). The main difference is
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* that it uses a file descriptor to determine the file location.
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*
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* 0 will be returned on success, and a -ve error code if unsuccessful.
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*/
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int vfs_fstat(int fd, struct kstat *stat)
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{
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struct fd f;
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int error;
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f = fdget_raw(fd);
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if (!f.file)
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return -EBADF;
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error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
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fdput(f);
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return error;
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}
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int getname_statx_lookup_flags(int flags)
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{
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int lookup_flags = 0;
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if (!(flags & AT_SYMLINK_NOFOLLOW))
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lookup_flags |= LOOKUP_FOLLOW;
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if (!(flags & AT_NO_AUTOMOUNT))
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lookup_flags |= LOOKUP_AUTOMOUNT;
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if (flags & AT_EMPTY_PATH)
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lookup_flags |= LOOKUP_EMPTY;
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return lookup_flags;
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}
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/**
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* vfs_statx - Get basic and extra attributes by filename
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* @dfd: A file descriptor representing the base dir for a relative filename
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* @filename: The name of the file of interest
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* @flags: Flags to control the query
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* @stat: The result structure to fill in.
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* @request_mask: STATX_xxx flags indicating what the caller wants
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*
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* This function is a wrapper around vfs_getattr(). The main difference is
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* that it uses a filename and base directory to determine the file location.
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* Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
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* at the given name from being referenced.
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*
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* 0 will be returned on success, and a -ve error code if unsuccessful.
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*/
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static int vfs_statx(int dfd, struct filename *filename, int flags,
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struct kstat *stat, u32 request_mask)
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{
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struct path path;
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unsigned int lookup_flags = getname_statx_lookup_flags(flags);
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int error;
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if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
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AT_STATX_SYNC_TYPE))
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return -EINVAL;
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retry:
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error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
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if (error)
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goto out;
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error = vfs_getattr(&path, stat, request_mask, flags);
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if (request_mask & STATX_MNT_ID_UNIQUE) {
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stat->mnt_id = real_mount(path.mnt)->mnt_id_unique;
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stat->result_mask |= STATX_MNT_ID_UNIQUE;
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} else {
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stat->mnt_id = real_mount(path.mnt)->mnt_id;
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stat->result_mask |= STATX_MNT_ID;
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}
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if (path.mnt->mnt_root == path.dentry)
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stat->attributes |= STATX_ATTR_MOUNT_ROOT;
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stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
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/* Handle STATX_DIOALIGN for block devices. */
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if (request_mask & STATX_DIOALIGN) {
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struct inode *inode = d_backing_inode(path.dentry);
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if (S_ISBLK(inode->i_mode))
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bdev_statx_dioalign(inode, stat);
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}
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path_put(&path);
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if (retry_estale(error, lookup_flags)) {
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lookup_flags |= LOOKUP_REVAL;
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goto retry;
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}
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out:
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return error;
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}
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int vfs_fstatat(int dfd, const char __user *filename,
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struct kstat *stat, int flags)
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{
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int ret;
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int statx_flags = flags | AT_NO_AUTOMOUNT;
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struct filename *name;
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/*
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* Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH)
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*
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* If AT_EMPTY_PATH is set, we expect the common case to be that
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* empty path, and avoid doing all the extra pathname work.
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*/
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if (dfd >= 0 && flags == AT_EMPTY_PATH) {
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char c;
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ret = get_user(c, filename);
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if (unlikely(ret))
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return ret;
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if (likely(!c))
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return vfs_fstat(dfd, stat);
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}
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name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL);
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ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
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putname(name);
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return ret;
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}
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#ifdef __ARCH_WANT_OLD_STAT
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/*
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* For backward compatibility? Maybe this should be moved
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* into arch/i386 instead?
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*/
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static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
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{
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static int warncount = 5;
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struct __old_kernel_stat tmp;
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if (warncount > 0) {
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warncount--;
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printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
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current->comm);
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} else if (warncount < 0) {
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/* it's laughable, but... */
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warncount = 0;
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}
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memset(&tmp, 0, sizeof(struct __old_kernel_stat));
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tmp.st_dev = old_encode_dev(stat->dev);
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tmp.st_ino = stat->ino;
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if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
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return -EOVERFLOW;
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tmp.st_mode = stat->mode;
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tmp.st_nlink = stat->nlink;
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if (tmp.st_nlink != stat->nlink)
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return -EOVERFLOW;
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SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
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SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
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tmp.st_rdev = old_encode_dev(stat->rdev);
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#if BITS_PER_LONG == 32
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if (stat->size > MAX_NON_LFS)
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return -EOVERFLOW;
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#endif
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tmp.st_size = stat->size;
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tmp.st_atime = stat->atime.tv_sec;
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tmp.st_mtime = stat->mtime.tv_sec;
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tmp.st_ctime = stat->ctime.tv_sec;
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return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
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}
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SYSCALL_DEFINE2(stat, const char __user *, filename,
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struct __old_kernel_stat __user *, statbuf)
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{
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struct kstat stat;
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int error;
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error = vfs_stat(filename, &stat);
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if (error)
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return error;
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return cp_old_stat(&stat, statbuf);
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}
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SYSCALL_DEFINE2(lstat, const char __user *, filename,
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struct __old_kernel_stat __user *, statbuf)
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{
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struct kstat stat;
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int error;
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error = vfs_lstat(filename, &stat);
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if (error)
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return error;
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return cp_old_stat(&stat, statbuf);
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}
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SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
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{
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struct kstat stat;
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int error = vfs_fstat(fd, &stat);
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if (!error)
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error = cp_old_stat(&stat, statbuf);
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return error;
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}
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#endif /* __ARCH_WANT_OLD_STAT */
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#ifdef __ARCH_WANT_NEW_STAT
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#ifndef INIT_STRUCT_STAT_PADDING
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# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
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#endif
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static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
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{
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struct stat tmp;
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if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
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return -EOVERFLOW;
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if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
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return -EOVERFLOW;
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#if BITS_PER_LONG == 32
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if (stat->size > MAX_NON_LFS)
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return -EOVERFLOW;
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#endif
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INIT_STRUCT_STAT_PADDING(tmp);
|
|
tmp.st_dev = new_encode_dev(stat->dev);
|
|
tmp.st_ino = stat->ino;
|
|
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
|
|
return -EOVERFLOW;
|
|
tmp.st_mode = stat->mode;
|
|
tmp.st_nlink = stat->nlink;
|
|
if (tmp.st_nlink != stat->nlink)
|
|
return -EOVERFLOW;
|
|
SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
|
|
SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
|
|
tmp.st_rdev = new_encode_dev(stat->rdev);
|
|
tmp.st_size = stat->size;
|
|
tmp.st_atime = stat->atime.tv_sec;
|
|
tmp.st_mtime = stat->mtime.tv_sec;
|
|
tmp.st_ctime = stat->ctime.tv_sec;
|
|
#ifdef STAT_HAVE_NSEC
|
|
tmp.st_atime_nsec = stat->atime.tv_nsec;
|
|
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
|
|
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
|
|
#endif
|
|
tmp.st_blocks = stat->blocks;
|
|
tmp.st_blksize = stat->blksize;
|
|
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(newstat, const char __user *, filename,
|
|
struct stat __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_stat(filename, &stat);
|
|
|
|
if (error)
|
|
return error;
|
|
return cp_new_stat(&stat, statbuf);
|
|
}
|
|
|
|
SYSCALL_DEFINE2(newlstat, const char __user *, filename,
|
|
struct stat __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
error = vfs_lstat(filename, &stat);
|
|
if (error)
|
|
return error;
|
|
|
|
return cp_new_stat(&stat, statbuf);
|
|
}
|
|
|
|
#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
|
|
SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
|
|
struct stat __user *, statbuf, int, flag)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
error = vfs_fstatat(dfd, filename, &stat, flag);
|
|
if (error)
|
|
return error;
|
|
return cp_new_stat(&stat, statbuf);
|
|
}
|
|
#endif
|
|
|
|
SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_fstat(fd, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
#endif
|
|
|
|
static int do_readlinkat(int dfd, const char __user *pathname,
|
|
char __user *buf, int bufsiz)
|
|
{
|
|
struct path path;
|
|
int error;
|
|
int empty = 0;
|
|
unsigned int lookup_flags = LOOKUP_EMPTY;
|
|
|
|
if (bufsiz <= 0)
|
|
return -EINVAL;
|
|
|
|
retry:
|
|
error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
|
|
if (!error) {
|
|
struct inode *inode = d_backing_inode(path.dentry);
|
|
|
|
error = empty ? -ENOENT : -EINVAL;
|
|
/*
|
|
* AFS mountpoints allow readlink(2) but are not symlinks
|
|
*/
|
|
if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
|
|
error = security_inode_readlink(path.dentry);
|
|
if (!error) {
|
|
touch_atime(&path);
|
|
error = vfs_readlink(path.dentry, buf, bufsiz);
|
|
}
|
|
}
|
|
path_put(&path);
|
|
if (retry_estale(error, lookup_flags)) {
|
|
lookup_flags |= LOOKUP_REVAL;
|
|
goto retry;
|
|
}
|
|
}
|
|
return error;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
|
|
char __user *, buf, int, bufsiz)
|
|
{
|
|
return do_readlinkat(dfd, pathname, buf, bufsiz);
|
|
}
|
|
|
|
SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
|
|
int, bufsiz)
|
|
{
|
|
return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
|
|
}
|
|
|
|
|
|
/* ---------- LFS-64 ----------- */
|
|
#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
|
|
|
|
#ifndef INIT_STRUCT_STAT64_PADDING
|
|
# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
|
|
#endif
|
|
|
|
static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
|
|
{
|
|
struct stat64 tmp;
|
|
|
|
INIT_STRUCT_STAT64_PADDING(tmp);
|
|
#ifdef CONFIG_MIPS
|
|
/* mips has weird padding, so we don't get 64 bits there */
|
|
tmp.st_dev = new_encode_dev(stat->dev);
|
|
tmp.st_rdev = new_encode_dev(stat->rdev);
|
|
#else
|
|
tmp.st_dev = huge_encode_dev(stat->dev);
|
|
tmp.st_rdev = huge_encode_dev(stat->rdev);
|
|
#endif
|
|
tmp.st_ino = stat->ino;
|
|
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
|
|
return -EOVERFLOW;
|
|
#ifdef STAT64_HAS_BROKEN_ST_INO
|
|
tmp.__st_ino = stat->ino;
|
|
#endif
|
|
tmp.st_mode = stat->mode;
|
|
tmp.st_nlink = stat->nlink;
|
|
tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
|
|
tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
|
|
tmp.st_atime = stat->atime.tv_sec;
|
|
tmp.st_atime_nsec = stat->atime.tv_nsec;
|
|
tmp.st_mtime = stat->mtime.tv_sec;
|
|
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
|
|
tmp.st_ctime = stat->ctime.tv_sec;
|
|
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
|
|
tmp.st_size = stat->size;
|
|
tmp.st_blocks = stat->blocks;
|
|
tmp.st_blksize = stat->blksize;
|
|
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(stat64, const char __user *, filename,
|
|
struct stat64 __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_stat(filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat64(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(lstat64, const char __user *, filename,
|
|
struct stat64 __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_lstat(filename, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat64(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_fstat(fd, &stat);
|
|
|
|
if (!error)
|
|
error = cp_new_stat64(&stat, statbuf);
|
|
|
|
return error;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
|
|
struct stat64 __user *, statbuf, int, flag)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
error = vfs_fstatat(dfd, filename, &stat, flag);
|
|
if (error)
|
|
return error;
|
|
return cp_new_stat64(&stat, statbuf);
|
|
}
|
|
#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
|
|
|
|
static noinline_for_stack int
|
|
cp_statx(const struct kstat *stat, struct statx __user *buffer)
|
|
{
|
|
struct statx tmp;
|
|
|
|
memset(&tmp, 0, sizeof(tmp));
|
|
|
|
/* STATX_CHANGE_COOKIE is kernel-only for now */
|
|
tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
|
|
tmp.stx_blksize = stat->blksize;
|
|
/* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
|
|
tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
|
|
tmp.stx_nlink = stat->nlink;
|
|
tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
|
|
tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
|
|
tmp.stx_mode = stat->mode;
|
|
tmp.stx_ino = stat->ino;
|
|
tmp.stx_size = stat->size;
|
|
tmp.stx_blocks = stat->blocks;
|
|
tmp.stx_attributes_mask = stat->attributes_mask;
|
|
tmp.stx_atime.tv_sec = stat->atime.tv_sec;
|
|
tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
|
|
tmp.stx_btime.tv_sec = stat->btime.tv_sec;
|
|
tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
|
|
tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
|
|
tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
|
|
tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
|
|
tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
|
|
tmp.stx_rdev_major = MAJOR(stat->rdev);
|
|
tmp.stx_rdev_minor = MINOR(stat->rdev);
|
|
tmp.stx_dev_major = MAJOR(stat->dev);
|
|
tmp.stx_dev_minor = MINOR(stat->dev);
|
|
tmp.stx_mnt_id = stat->mnt_id;
|
|
tmp.stx_dio_mem_align = stat->dio_mem_align;
|
|
tmp.stx_dio_offset_align = stat->dio_offset_align;
|
|
|
|
return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
|
|
}
|
|
|
|
int do_statx(int dfd, struct filename *filename, unsigned int flags,
|
|
unsigned int mask, struct statx __user *buffer)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
if (mask & STATX__RESERVED)
|
|
return -EINVAL;
|
|
if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
|
|
return -EINVAL;
|
|
|
|
/* STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
|
|
* from userland.
|
|
*/
|
|
mask &= ~STATX_CHANGE_COOKIE;
|
|
|
|
error = vfs_statx(dfd, filename, flags, &stat, mask);
|
|
if (error)
|
|
return error;
|
|
|
|
return cp_statx(&stat, buffer);
|
|
}
|
|
|
|
/**
|
|
* sys_statx - System call to get enhanced stats
|
|
* @dfd: Base directory to pathwalk from *or* fd to stat.
|
|
* @filename: File to stat or "" with AT_EMPTY_PATH
|
|
* @flags: AT_* flags to control pathwalk.
|
|
* @mask: Parts of statx struct actually required.
|
|
* @buffer: Result buffer.
|
|
*
|
|
* Note that fstat() can be emulated by setting dfd to the fd of interest,
|
|
* supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
|
|
*/
|
|
SYSCALL_DEFINE5(statx,
|
|
int, dfd, const char __user *, filename, unsigned, flags,
|
|
unsigned int, mask,
|
|
struct statx __user *, buffer)
|
|
{
|
|
int ret;
|
|
struct filename *name;
|
|
|
|
name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL);
|
|
ret = do_statx(dfd, name, flags, mask, buffer);
|
|
putname(name);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
|
|
static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
|
|
{
|
|
struct compat_stat tmp;
|
|
|
|
if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
|
|
return -EOVERFLOW;
|
|
if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
|
|
return -EOVERFLOW;
|
|
|
|
memset(&tmp, 0, sizeof(tmp));
|
|
tmp.st_dev = new_encode_dev(stat->dev);
|
|
tmp.st_ino = stat->ino;
|
|
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
|
|
return -EOVERFLOW;
|
|
tmp.st_mode = stat->mode;
|
|
tmp.st_nlink = stat->nlink;
|
|
if (tmp.st_nlink != stat->nlink)
|
|
return -EOVERFLOW;
|
|
SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
|
|
SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
|
|
tmp.st_rdev = new_encode_dev(stat->rdev);
|
|
if ((u64) stat->size > MAX_NON_LFS)
|
|
return -EOVERFLOW;
|
|
tmp.st_size = stat->size;
|
|
tmp.st_atime = stat->atime.tv_sec;
|
|
tmp.st_atime_nsec = stat->atime.tv_nsec;
|
|
tmp.st_mtime = stat->mtime.tv_sec;
|
|
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
|
|
tmp.st_ctime = stat->ctime.tv_sec;
|
|
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
|
|
tmp.st_blocks = stat->blocks;
|
|
tmp.st_blksize = stat->blksize;
|
|
return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
|
|
struct compat_stat __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
error = vfs_stat(filename, &stat);
|
|
if (error)
|
|
return error;
|
|
return cp_compat_stat(&stat, statbuf);
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
|
|
struct compat_stat __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
error = vfs_lstat(filename, &stat);
|
|
if (error)
|
|
return error;
|
|
return cp_compat_stat(&stat, statbuf);
|
|
}
|
|
|
|
#ifndef __ARCH_WANT_STAT64
|
|
COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
|
|
const char __user *, filename,
|
|
struct compat_stat __user *, statbuf, int, flag)
|
|
{
|
|
struct kstat stat;
|
|
int error;
|
|
|
|
error = vfs_fstatat(dfd, filename, &stat, flag);
|
|
if (error)
|
|
return error;
|
|
return cp_compat_stat(&stat, statbuf);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
|
|
struct compat_stat __user *, statbuf)
|
|
{
|
|
struct kstat stat;
|
|
int error = vfs_fstat(fd, &stat);
|
|
|
|
if (!error)
|
|
error = cp_compat_stat(&stat, statbuf);
|
|
return error;
|
|
}
|
|
#endif
|
|
|
|
/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
|
|
void __inode_add_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
inode->i_blocks += bytes >> 9;
|
|
bytes &= 511;
|
|
inode->i_bytes += bytes;
|
|
if (inode->i_bytes >= 512) {
|
|
inode->i_blocks++;
|
|
inode->i_bytes -= 512;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(__inode_add_bytes);
|
|
|
|
void inode_add_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
__inode_add_bytes(inode, bytes);
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
|
|
EXPORT_SYMBOL(inode_add_bytes);
|
|
|
|
void __inode_sub_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
inode->i_blocks -= bytes >> 9;
|
|
bytes &= 511;
|
|
if (inode->i_bytes < bytes) {
|
|
inode->i_blocks--;
|
|
inode->i_bytes += 512;
|
|
}
|
|
inode->i_bytes -= bytes;
|
|
}
|
|
|
|
EXPORT_SYMBOL(__inode_sub_bytes);
|
|
|
|
void inode_sub_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
__inode_sub_bytes(inode, bytes);
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
|
|
EXPORT_SYMBOL(inode_sub_bytes);
|
|
|
|
loff_t inode_get_bytes(struct inode *inode)
|
|
{
|
|
loff_t ret;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
ret = __inode_get_bytes(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL(inode_get_bytes);
|
|
|
|
void inode_set_bytes(struct inode *inode, loff_t bytes)
|
|
{
|
|
/* Caller is here responsible for sufficient locking
|
|
* (ie. inode->i_lock) */
|
|
inode->i_blocks = bytes >> 9;
|
|
inode->i_bytes = bytes & 511;
|
|
}
|
|
|
|
EXPORT_SYMBOL(inode_set_bytes);
|