// SPDX-License-Identifier: GPL-2.0/* * linux/fs/stat.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/blkdev.h>#include <linux/export.h>#include <linux/mm.h>#include <linux/errno.h>#include <linux/file.h>#include <linux/highuid.h>#include <linux/fs.h>#include <linux/namei.h>#include <linux/security.h>#include <linux/cred.h>#include <linux/syscalls.h>#include <linux/pagemap.h>#include <linux/compat.h>#include <linux/iversion.h> #include <linux/uaccess.h>#include <asm/unistd.h> #include <trace/events/timestamp.h> #include "internal.h"#include "mount.h" /** * fill_mg_cmtime - Fill in the mtime and ctime and flag ctime as QUERIED * @stat: where to store the resulting values * @request_mask: STATX_* values requested * @inode: inode from which to grab the c/mtime * * Given @inode, grab the ctime and mtime out if it and store the result * in @stat. When fetching the value, flag it as QUERIED (if not already) * so the next write will record a distinct timestamp. * * NB: The QUERIED flag is tracked in the ctime, but we set it there even * if only the mtime was requested, as that ensures that the next mtime * change will be distinct. */void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode){ atomic_t *pcn = (atomic_t *)&inode->i_ctime_nsec; /* If neither time was requested, then don't report them */ if (!(request_mask & (STATX_CTIME|STATX_MTIME))) { stat->result_mask &= ~(STATX_CTIME|STATX_MTIME); return; } stat->mtime = inode_get_mtime(inode); stat->ctime.tv_sec = inode_get_ctime_sec(inode); stat->ctime.tv_nsec = (u32)atomic_read(pcn); if (!(stat->ctime.tv_nsec & I_CTIME_QUERIED)) stat->ctime.tv_nsec = ((u32)atomic_fetch_or(I_CTIME_QUERIED, pcn)); stat->ctime.tv_nsec &= ~I_CTIME_QUERIED; trace_fill_mg_cmtime(inode, &stat->ctime, &stat->mtime);}EXPORT_SYMBOL(fill_mg_cmtime); /** * generic_fillattr - Fill in the basic attributes from the inode struct * @idmap: idmap of the mount the inode was found from * @request_mask: statx request_mask * @inode: Inode to use as the source * @stat: Where to fill in the attributes * * Fill in the basic attributes in the kstat structure from data that's to be * found on the VFS inode structure. This is the default if no getattr inode * operation is supplied. * * If the inode has been found through an idmapped mount the idmap of * the vfsmount must be passed through @idmap. This function will then * take care to map the inode according to @idmap before filling in the * uid and gid filds. On non-idmapped mounts or if permission checking is to be * performed on the raw inode simply pass @nop_mnt_idmap. */void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask, struct inode *inode, struct kstat *stat){ vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode); vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); stat->dev = inode->i_sb->s_dev; stat->ino = inode->i_ino; stat->mode = inode->i_mode; stat->nlink = inode->i_nlink; stat->uid = vfsuid_into_kuid(vfsuid); stat->gid = vfsgid_into_kgid(vfsgid); stat->rdev = inode->i_rdev; stat->size = i_size_read(inode); stat->atime = inode_get_atime(inode); if (is_mgtime(inode)) { fill_mg_cmtime(stat, request_mask, inode); } else { stat->ctime = inode_get_ctime(inode); stat->mtime = inode_get_mtime(inode); } stat->blksize = i_blocksize(inode); stat->blocks = inode->i_blocks; if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) { stat->result_mask |= STATX_CHANGE_COOKIE; stat->change_cookie = inode_query_iversion(inode); } }EXPORT_SYMBOL(generic_fillattr); /** * generic_fill_statx_attr - Fill in the statx attributes from the inode flags * @inode: Inode to use as the source * @stat: Where to fill in the attribute flags * * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the * inode that are published on i_flags and enforced by the VFS. */void generic_fill_statx_attr(struct inode *inode, struct kstat *stat){ if (inode->i_flags & S_IMMUTABLE) stat->attributes |= STATX_ATTR_IMMUTABLE; if (inode->i_flags & S_APPEND) stat->attributes |= STATX_ATTR_APPEND; stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;}EXPORT_SYMBOL(generic_fill_statx_attr); /** * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes * @stat: Where to fill in the attribute flags * @unit_min: Minimum supported atomic write length in bytes * @unit_max: Maximum supported atomic write length in bytes * @unit_max_opt: Optimised maximum supported atomic write length in bytes * * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from * atomic write unit_min and unit_max values. */void generic_fill_statx_atomic_writes(struct kstat *stat, unsigned int unit_min, unsigned int unit_max, unsigned int unit_max_opt){ /* Confirm that the request type is known */ stat->result_mask |= STATX_WRITE_ATOMIC; /* Confirm that the file attribute type is known */ stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC; if (unit_min) { stat->atomic_write_unit_min = unit_min; stat->atomic_write_unit_max = unit_max; stat->atomic_write_unit_max_opt = unit_max_opt; /* Initially only allow 1x segment */ stat->atomic_write_segments_max = 1; /* Confirm atomic writes are actually supported */ stat->attributes |= STATX_ATTR_WRITE_ATOMIC; }}EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes); /** * vfs_getattr_nosec - getattr without security checks * @path: file to get attributes from * @stat: structure to return attributes in * @request_mask: STATX_xxx flags indicating what the caller wants * @query_flags: Query mode (AT_STATX_SYNC_TYPE) * * Get attributes without calling security_inode_getattr. * * Currently the only caller other than vfs_getattr is internal to the * filehandle lookup code, which uses only the inode number and returns no * attributes to any user. Any other code probably wants vfs_getattr. */int vfs_getattr_nosec(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags){ struct mnt_idmap *idmap; struct inode *inode = d_backing_inode(path->dentry); memset(stat, 0, sizeof(*stat)); stat->result_mask |= STATX_BASIC_STATS; query_flags &= AT_STATX_SYNC_TYPE; /* allow the fs to override these if it really wants to */ /* SB_NOATIME means filesystem supplies dummy atime value */ if (inode->i_sb->s_flags & SB_NOATIME) stat->result_mask &= ~STATX_ATIME; /* * Note: If you add another clause to set an attribute flag, please * update attributes_mask below. */ if (IS_AUTOMOUNT(inode)) stat->attributes |= STATX_ATTR_AUTOMOUNT; if (IS_DAX(inode)) stat->attributes |= STATX_ATTR_DAX; stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | STATX_ATTR_DAX); idmap = mnt_idmap(path->mnt); if (inode->i_op->getattr) { int ret; ret = inode->i_op->getattr(idmap, path, stat, request_mask, query_flags); if (ret) return ret; } else { generic_fillattr(idmap, request_mask, inode, stat); } /* * If this is a block device inode, override the filesystem attributes * with the block device specific parameters that need to be obtained * from the bdev backing inode. */ if (S_ISBLK(stat->mode)) bdev_statx(path, stat, request_mask); return 0;}EXPORT_SYMBOL(vfs_getattr_nosec); /* * vfs_getattr - Get the enhanced basic attributes of a file * @path: The file of interest * @stat: Where to return the statistics * @request_mask: STATX_xxx flags indicating what the caller wants * @query_flags: Query mode (AT_STATX_SYNC_TYPE) * * Ask the filesystem for a file's attributes. The caller must indicate in * request_mask and query_flags to indicate what they want. * * If the file is remote, the filesystem can be forced to update the attributes * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can * suppress the update by passing AT_STATX_DONT_SYNC. * * Bits must have been set in request_mask to indicate which attributes the * caller wants retrieving. Any such attribute not requested may be returned * anyway, but the value may be approximate, and, if remote, may not have been * synchronised with the server. * * 0 will be returned on success, and a -ve error code if unsuccessful. */int vfs_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags){ int retval; retval = security_inode_getattr(path); if (unlikely(retval)) return retval; return vfs_getattr_nosec(path, stat, request_mask, query_flags);}EXPORT_SYMBOL(vfs_getattr); /** * vfs_fstat - Get the basic attributes by file descriptor * @fd: The file descriptor referring to the file of interest * @stat: The result structure to fill in. * * This function is a wrapper around vfs_getattr(). The main difference is * that it uses a file descriptor to determine the file location. * * 0 will be returned on success, and a -ve error code if unsuccessful. */int vfs_fstat(int fd, struct kstat *stat){ CLASS(fd_raw, f)(fd); if (fd_empty(f)) return -EBADF; return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);} static int statx_lookup_flags(int flags){ int lookup_flags = 0; if (!(flags & AT_SYMLINK_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; if (!(flags & AT_NO_AUTOMOUNT)) lookup_flags |= LOOKUP_AUTOMOUNT; return lookup_flags;} static int vfs_statx_path(const struct path *path, int flags, struct kstat *stat, u32 request_mask){ int error = vfs_getattr(path, stat, request_mask, flags); if (error) return error; if (request_mask & STATX_MNT_ID_UNIQUE) { stat->mnt_id = real_mount(path->mnt)->mnt_id_unique; stat->result_mask |= STATX_MNT_ID_UNIQUE; } else { stat->mnt_id = real_mount(path->mnt)->mnt_id; stat->result_mask |= STATX_MNT_ID; } if (path_mounted(path)) stat->attributes |= STATX_ATTR_MOUNT_ROOT; stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; return 0;} static int vfs_statx_fd(int fd, int flags, struct kstat *stat, u32 request_mask){ CLASS(fd_raw, f)(fd); if (fd_empty(f)) return -EBADF; return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);} /** * vfs_statx - Get basic and extra attributes by filename * @dfd: A file descriptor representing the base dir for a relative filename * @filename: The name of the file of interest * @flags: Flags to control the query * @stat: The result structure to fill in. * @request_mask: STATX_xxx flags indicating what the caller wants * * This function is a wrapper around vfs_getattr(). The main difference is * that it uses a filename and base directory to determine the file location. * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink * at the given name from being referenced. * * 0 will be returned on success, and a -ve error code if unsuccessful. */static int vfs_statx(int dfd, struct filename *filename, int flags, struct kstat *stat, u32 request_mask){ struct path path; unsigned int lookup_flags = statx_lookup_flags(flags); int error; if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH | AT_STATX_SYNC_TYPE)) return -EINVAL; retry: error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); if (error) return error; error = vfs_statx_path(&path, flags, stat, request_mask); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } return error;} int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, int flags){ CLASS(filename_maybe_null, name)(filename, flags); if (!name && dfd >= 0) return vfs_fstat(dfd, stat); return vfs_statx(dfd, name, flags | AT_NO_AUTOMOUNT, stat, STATX_BASIC_STATS);} #ifdef __ARCH_WANT_OLD_STAT /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf){ static int warncount = 5; struct __old_kernel_stat tmp; if (warncount > 0) { warncount--; printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", current->comm); } else if (warncount < 0) { /* it's laughable, but... */ warncount = 0; } memset(&tmp, 0, sizeof(struct __old_kernel_stat)); tmp.st_dev = old_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 = old_encode_dev(stat->rdev);#if BITS_PER_LONG == 32 if (stat->size > MAX_NON_LFS) return -EOVERFLOW;#endif 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; return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;} SYSCALL_DEFINE2(stat, const char __user *, filename, struct __old_kernel_stat __user *, statbuf){ struct kstat stat; int error; error = vfs_stat(filename, &stat); if (unlikely(error)) return error; return cp_old_stat(&stat, statbuf);} SYSCALL_DEFINE2(lstat, const char __user *, filename, struct __old_kernel_stat __user *, statbuf){ struct kstat stat; int error; error = vfs_lstat(filename, &stat); if (unlikely(error)) return error; return cp_old_stat(&stat, statbuf);} SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf){ struct kstat stat; int error; error = vfs_fstat(fd, &stat); if (unlikely(error)) return error; return cp_old_stat(&stat, statbuf);} #endif /* __ARCH_WANT_OLD_STAT */ #ifdef __ARCH_WANT_NEW_STAT #ifndef INIT_STRUCT_STAT_PADDING# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))#endif static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf){ struct 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;#if BITS_PER_LONG == 32 if (stat->size > MAX_NON_LFS) return -EOVERFLOW;#endif 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;Lines 1–500 of 968. Load more
// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/stat.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/blkdev.h> #include <linux/export.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/file.h> #include <linux/highuid.h> #include <linux/fs.h> #include <linux/namei.h> #include <linux/security.h> #include <linux/cred.h> #include <linux/syscalls.h> #include <linux/pagemap.h> #include <linux/compat.h> #include <linux/iversion.h> #include <linux/uaccess.h> #include <asm/unistd.h> #include <trace/events/timestamp.h> #include "internal.h" #include "mount.h" /** * fill_mg_cmtime - Fill in the mtime and ctime and flag ctime as QUERIED * @stat: where to store the resulting values * @request_mask: STATX_* values requested * @inode: inode from which to grab the c/mtime * * Given @inode, grab the ctime and mtime out if it and store the result * in @stat. When fetching the value, flag it as QUERIED (if not already) * so the next write will record a distinct timestamp. * * NB: The QUERIED flag is tracked in the ctime, but we set it there even * if only the mtime was requested, as that ensures that the next mtime * change will be distinct. */ void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode) { atomic_t *pcn = (atomic_t *)&inode->i_ctime_nsec; /* If neither time was requested, then don't report them */ if (!(request_mask & (STATX_CTIME|STATX_MTIME))) { stat->result_mask &= ~(STATX_CTIME|STATX_MTIME); return; } stat->mtime = inode_get_mtime(inode); stat->ctime.tv_sec = inode_get_ctime_sec(inode); stat->ctime.tv_nsec = (u32)atomic_read(pcn); if (!(stat->ctime.tv_nsec & I_CTIME_QUERIED)) stat->ctime.tv_nsec = ((u32)atomic_fetch_or(I_CTIME_QUERIED, pcn)); stat->ctime.tv_nsec &= ~I_CTIME_QUERIED; trace_fill_mg_cmtime(inode, &stat->ctime, &stat->mtime); } EXPORT_SYMBOL(fill_mg_cmtime); /** * generic_fillattr - Fill in the basic attributes from the inode struct * @idmap: idmap of the mount the inode was found from * @request_mask: statx request_mask * @inode: Inode to use as the source * @stat: Where to fill in the attributes * * Fill in the basic attributes in the kstat structure from data that's to be * found on the VFS inode structure. This is the default if no getattr inode * operation is supplied. * * If the inode has been found through an idmapped mount the idmap of * the vfsmount must be passed through @idmap. This function will then * take care to map the inode according to @idmap before filling in the * uid and gid filds. On non-idmapped mounts or if permission checking is to be * performed on the raw inode simply pass @nop_mnt_idmap. */ void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask, struct inode *inode, struct kstat *stat) { vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode); vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); stat->dev = inode->i_sb->s_dev; stat->ino = inode->i_ino; stat->mode = inode->i_mode; stat->nlink = inode->i_nlink; stat->uid = vfsuid_into_kuid(vfsuid); stat->gid = vfsgid_into_kgid(vfsgid); stat->rdev = inode->i_rdev; stat->size = i_size_read(inode); stat->atime = inode_get_atime(inode); if (is_mgtime(inode)) { fill_mg_cmtime(stat, request_mask, inode); } else { stat->ctime = inode_get_ctime(inode); stat->mtime = inode_get_mtime(inode); } stat->blksize = i_blocksize(inode); stat->blocks = inode->i_blocks; if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) { stat->result_mask |= STATX_CHANGE_COOKIE; stat->change_cookie = inode_query_iversion(inode); } } EXPORT_SYMBOL(generic_fillattr); /** * generic_fill_statx_attr - Fill in the statx attributes from the inode flags * @inode: Inode to use as the source * @stat: Where to fill in the attribute flags * * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the * inode that are published on i_flags and enforced by the VFS. */ void generic_fill_statx_attr(struct inode *inode, struct kstat *stat) { if (inode->i_flags & S_IMMUTABLE) stat->attributes |= STATX_ATTR_IMMUTABLE; if (inode->i_flags & S_APPEND) stat->attributes |= STATX_ATTR_APPEND; stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS; } EXPORT_SYMBOL(generic_fill_statx_attr); /** * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes * @stat: Where to fill in the attribute flags * @unit_min: Minimum supported atomic write length in bytes * @unit_max: Maximum supported atomic write length in bytes * @unit_max_opt: Optimised maximum supported atomic write length in bytes * * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from * atomic write unit_min and unit_max values. */ void generic_fill_statx_atomic_writes(struct kstat *stat, unsigned int unit_min, unsigned int unit_max, unsigned int unit_max_opt) { /* Confirm that the request type is known */ stat->result_mask |= STATX_WRITE_ATOMIC; /* Confirm that the file attribute type is known */ stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC; if (unit_min) { stat->atomic_write_unit_min = unit_min; stat->atomic_write_unit_max = unit_max; stat->atomic_write_unit_max_opt = unit_max_opt; /* Initially only allow 1x segment */ stat->atomic_write_segments_max = 1; /* Confirm atomic writes are actually supported */ stat->attributes |= STATX_ATTR_WRITE_ATOMIC; } } EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes); /** * vfs_getattr_nosec - getattr without security checks * @path: file to get attributes from * @stat: structure to return attributes in * @request_mask: STATX_xxx flags indicating what the caller wants * @query_flags: Query mode (AT_STATX_SYNC_TYPE) * * Get attributes without calling security_inode_getattr. * * Currently the only caller other than vfs_getattr is internal to the * filehandle lookup code, which uses only the inode number and returns no * attributes to any user. Any other code probably wants vfs_getattr. */ int vfs_getattr_nosec(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct mnt_idmap *idmap; struct inode *inode = d_backing_inode(path->dentry); memset(stat, 0, sizeof(*stat)); stat->result_mask |= STATX_BASIC_STATS; query_flags &= AT_STATX_SYNC_TYPE; /* allow the fs to override these if it really wants to */ /* SB_NOATIME means filesystem supplies dummy atime value */ if (inode->i_sb->s_flags & SB_NOATIME) stat->result_mask &= ~STATX_ATIME; /* * Note: If you add another clause to set an attribute flag, please * update attributes_mask below. */ if (IS_AUTOMOUNT(inode)) stat->attributes |= STATX_ATTR_AUTOMOUNT; if (IS_DAX(inode)) stat->attributes |= STATX_ATTR_DAX; stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | STATX_ATTR_DAX); idmap = mnt_idmap(path->mnt); if (inode->i_op->getattr) { int ret; ret = inode->i_op->getattr(idmap, path, stat, request_mask, query_flags); if (ret) return ret; } else { generic_fillattr(idmap, request_mask, inode, stat); } /* * If this is a block device inode, override the filesystem attributes * with the block device specific parameters that need to be obtained * from the bdev backing inode. */ if (S_ISBLK(stat->mode)) bdev_statx(path, stat, request_mask); return 0; } EXPORT_SYMBOL(vfs_getattr_nosec); /* * vfs_getattr - Get the enhanced basic attributes of a file * @path: The file of interest * @stat: Where to return the statistics * @request_mask: STATX_xxx flags indicating what the caller wants * @query_flags: Query mode (AT_STATX_SYNC_TYPE) * * Ask the filesystem for a file's attributes. The caller must indicate in * request_mask and query_flags to indicate what they want. * * If the file is remote, the filesystem can be forced to update the attributes * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can * suppress the update by passing AT_STATX_DONT_SYNC. * * Bits must have been set in request_mask to indicate which attributes the * caller wants retrieving. Any such attribute not requested may be returned * anyway, but the value may be approximate, and, if remote, may not have been * synchronised with the server. * * 0 will be returned on success, and a -ve error code if unsuccessful. */ int vfs_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { int retval; retval = security_inode_getattr(path); if (unlikely(retval)) return retval; return vfs_getattr_nosec(path, stat, request_mask, query_flags); } EXPORT_SYMBOL(vfs_getattr); /** * vfs_fstat - Get the basic attributes by file descriptor * @fd: The file descriptor referring to the file of interest * @stat: The result structure to fill in. * * This function is a wrapper around vfs_getattr(). The main difference is * that it uses a file descriptor to determine the file location. * * 0 will be returned on success, and a -ve error code if unsuccessful. */ int vfs_fstat(int fd, struct kstat *stat) { CLASS(fd_raw, f)(fd); if (fd_empty(f)) return -EBADF; return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0); } static int statx_lookup_flags(int flags) { int lookup_flags = 0; if (!(flags & AT_SYMLINK_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; if (!(flags & AT_NO_AUTOMOUNT)) lookup_flags |= LOOKUP_AUTOMOUNT; return lookup_flags; } static int vfs_statx_path(const struct path *path, int flags, struct kstat *stat, u32 request_mask) { int error = vfs_getattr(path, stat, request_mask, flags); if (error) return error; if (request_mask & STATX_MNT_ID_UNIQUE) { stat->mnt_id = real_mount(path->mnt)->mnt_id_unique; stat->result_mask |= STATX_MNT_ID_UNIQUE; } else { stat->mnt_id = real_mount(path->mnt)->mnt_id; stat->result_mask |= STATX_MNT_ID; } if (path_mounted(path)) stat->attributes |= STATX_ATTR_MOUNT_ROOT; stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; return 0; } static int vfs_statx_fd(int fd, int flags, struct kstat *stat, u32 request_mask) { CLASS(fd_raw, f)(fd); if (fd_empty(f)) return -EBADF; return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask); } /** * vfs_statx - Get basic and extra attributes by filename * @dfd: A file descriptor representing the base dir for a relative filename * @filename: The name of the file of interest * @flags: Flags to control the query * @stat: The result structure to fill in. * @request_mask: STATX_xxx flags indicating what the caller wants * * This function is a wrapper around vfs_getattr(). The main difference is * that it uses a filename and base directory to determine the file location. * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink * at the given name from being referenced. * * 0 will be returned on success, and a -ve error code if unsuccessful. */ static int vfs_statx(int dfd, struct filename *filename, int flags, struct kstat *stat, u32 request_mask) { struct path path; unsigned int lookup_flags = statx_lookup_flags(flags); int error; if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH | AT_STATX_SYNC_TYPE)) return -EINVAL; retry: error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); if (error) return error; error = vfs_statx_path(&path, flags, stat, request_mask); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } return error; } int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, int flags) { CLASS(filename_maybe_null, name)(filename, flags); if (!name && dfd >= 0) return vfs_fstat(dfd, stat); return vfs_statx(dfd, name, flags | AT_NO_AUTOMOUNT, stat, STATX_BASIC_STATS); } #ifdef __ARCH_WANT_OLD_STAT /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) { static int warncount = 5; struct __old_kernel_stat tmp; if (warncount > 0) { warncount--; printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", current->comm); } else if (warncount < 0) { /* it's laughable, but... */ warncount = 0; } memset(&tmp, 0, sizeof(struct __old_kernel_stat)); tmp.st_dev = old_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 = old_encode_dev(stat->rdev); #if BITS_PER_LONG == 32 if (stat->size > MAX_NON_LFS) return -EOVERFLOW; #endif 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; return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; } SYSCALL_DEFINE2(stat, const char __user *, filename, struct __old_kernel_stat __user *, statbuf) { struct kstat stat; int error; error = vfs_stat(filename, &stat); if (unlikely(error)) return error; return cp_old_stat(&stat, statbuf); } SYSCALL_DEFINE2(lstat, const char __user *, filename, struct __old_kernel_stat __user *, statbuf) { struct kstat stat; int error; error = vfs_lstat(filename, &stat); if (unlikely(error)) return error; return cp_old_stat(&stat, statbuf); } SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) { struct kstat stat; int error; error = vfs_fstat(fd, &stat); if (unlikely(error)) return error; return cp_old_stat(&stat, statbuf); } #endif /* __ARCH_WANT_OLD_STAT */ #ifdef __ARCH_WANT_NEW_STAT #ifndef INIT_STRUCT_STAT_PADDING # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) #endif static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) { struct 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; #if BITS_PER_LONG == 32 if (stat->size > MAX_NON_LFS) return -EOVERFLOW; #endif 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;