cregit-Linux how code gets into the kernel

Release 4.11 fs/open.c

Directory: fs
/*
 *  linux/fs/open.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/string.h>
#include <linux/mm.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/fsnotify.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/namei.h>
#include <linux/backing-dev.h>
#include <linux/capability.h>
#include <linux/securebits.h>
#include <linux/security.h>
#include <linux/mount.h>
#include <linux/fcntl.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/personality.h>
#include <linux/pagemap.h>
#include <linux/syscalls.h>
#include <linux/rcupdate.h>
#include <linux/audit.h>
#include <linux/falloc.h>
#include <linux/fs_struct.h>
#include <linux/ima.h>
#include <linux/dnotify.h>
#include <linux/compat.h>

#include "internal.h"


int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, struct file *filp) { int ret; struct iattr newattrs; /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ if (length < 0) return -EINVAL; newattrs.ia_size = length; newattrs.ia_valid = ATTR_SIZE | time_attrs; if (filp) { newattrs.ia_file = filp; newattrs.ia_valid |= ATTR_FILE; } /* Remove suid, sgid, and file capabilities on truncate too */ ret = dentry_needs_remove_privs(dentry); if (ret < 0) return ret; if (ret) newattrs.ia_valid |= ret | ATTR_FORCE; inode_lock(dentry->d_inode); /* Note any delegations or leases have already been broken: */ ret = notify_change(dentry, &newattrs, NULL); inode_unlock(dentry->d_inode); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4937.40%538.46%
Miklos Szeredi2317.56%17.69%
Al Viro1914.50%215.38%
Américo Wang1712.98%17.69%
Jan Kara118.40%17.69%
Neil Brown53.82%17.69%
Linus Torvalds43.05%17.69%
J. Bruce Fields32.29%17.69%
Total131100.00%13100.00%


long vfs_truncate(const struct path *path, loff_t length) { struct inode *inode; struct dentry *upperdentry; long error; inode = path->dentry->d_inode; /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ if (S_ISDIR(inode->i_mode)) return -EISDIR; if (!S_ISREG(inode->i_mode)) return -EINVAL; error = mnt_want_write(path->mnt); if (error) goto out; error = inode_permission(inode, MAY_WRITE); if (error) goto mnt_drop_write_and_out; error = -EPERM; if (IS_APPEND(inode)) goto mnt_drop_write_and_out; /* * If this is an overlayfs then do as if opening the file so we get * write access on the upper inode, not on the overlay inode. For * non-overlay filesystems d_real() is an identity function. */ upperdentry = d_real(path->dentry, NULL, O_WRONLY); error = PTR_ERR(upperdentry); if (IS_ERR(upperdentry)) goto mnt_drop_write_and_out; error = get_write_access(upperdentry->d_inode); if (error) goto mnt_drop_write_and_out; /* * Make sure that there are no leases. get_write_access() protects * against the truncate racing with a lease-granting setlease(). */ error = break_lease(inode, O_WRONLY); if (error) goto put_write_and_out; error = locks_verify_truncate(inode, NULL, length); if (!error) error = security_path_truncate(path); if (!error) error = do_truncate(path->dentry, length, 0, NULL); put_write_and_out: put_write_access(upperdentry->d_inode); mnt_drop_write_and_out: mnt_drop_write(path->mnt); out: return error; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)11748.75%1860.00%
Miklos Szeredi4418.33%26.67%
David Howells229.17%13.33%
Dave Hansen197.92%13.33%
Kentaro Takeda125.00%13.33%
Linus Torvalds114.58%13.33%
David M. Richter72.92%13.33%
Al Viro41.67%310.00%
Neil Brown20.83%13.33%
Jan Blunck20.83%13.33%
Total240100.00%30100.00%

EXPORT_SYMBOL_GPL(vfs_truncate);
static long do_sys_truncate(const char __user *pathname, loff_t length) { unsigned int lookup_flags = LOOKUP_FOLLOW; struct path path; int error; if (length < 0) /* sorry, but loff_t says... */ return -EINVAL; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (!error) { error = vfs_truncate(&path, length); path_put(&path); } if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } return error; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells5858.59%116.67%
Jeff Layton3131.31%116.67%
Linus Torvalds (pre-git)88.08%350.00%
Jan Blunck22.02%116.67%
Total99100.00%6100.00%

SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) { return do_sys_truncate(path, length); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length) { return do_sys_truncate(path, length); } #endif
static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) { struct inode *inode; struct dentry *dentry; struct fd f; int error; error = -EINVAL; if (length < 0) goto out; error = -EBADF; f = fdget(fd); if (!f.file) goto out; /* explicitly opened as large or we are on 64-bit box */ if (f.file->f_flags & O_LARGEFILE) small = 0; dentry = f.file->f_path.dentry; inode = dentry->d_inode; error = -EINVAL; if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) goto out_putf; error = -EINVAL; /* Cannot ftruncate over 2^31 bytes without large file support */ if (small && length > MAX_NON_LFS) goto out_putf; error = -EPERM; if (IS_APPEND(inode)) goto out_putf; sb_start_write(inode->i_sb); error = locks_verify_truncate(inode, f.file, length); if (!error) error = security_path_truncate(&f.file->f_path); if (!error) error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file); sb_end_write(inode->i_sb); out_putf: fdput(f); out: return error; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)14761.51%1768.00%
Linus Torvalds3414.23%14.00%
Al Viro208.37%14.00%
Kentaro Takeda156.28%14.00%
Jan Kara145.86%14.00%
Josef 'Jeff' Sipek31.26%14.00%
Peter Staubach31.26%14.00%
Miklos Szeredi20.84%14.00%
Neil Brown10.42%14.00%
Total239100.00%25100.00%

SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) { return do_sys_ftruncate(fd, length, 1); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) { return do_sys_ftruncate(fd, length, 1); } #endif /* LFS versions of truncate are only needed on 32 bit machines */ #if BITS_PER_LONG == 32 SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length) { return do_sys_truncate(path, length); } SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length) { return do_sys_ftruncate(fd, length, 0); } #endif /* BITS_PER_LONG == 32 */
int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); long ret; if (offset < 0 || len <= 0) return -EINVAL; /* Return error if mode is not supported */ if (mode & ~FALLOC_FL_SUPPORTED_MASK) return -EOPNOTSUPP; /* Punch hole and zero range are mutually exclusive */ if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) return -EOPNOTSUPP; /* Punch hole must have keep size set */ if ((mode & FALLOC_FL_PUNCH_HOLE) && !(mode & FALLOC_FL_KEEP_SIZE)) return -EOPNOTSUPP; /* Collapse range should only be used exclusively. */ if ((mode & FALLOC_FL_COLLAPSE_RANGE) && (mode & ~FALLOC_FL_COLLAPSE_RANGE)) return -EINVAL; /* Insert range should only be used exclusively. */ if ((mode & FALLOC_FL_INSERT_RANGE) && (mode & ~FALLOC_FL_INSERT_RANGE)) return -EINVAL; /* Unshare range should only be used with allocate mode. */ if ((mode & FALLOC_FL_UNSHARE_RANGE) && (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) return -EINVAL; if (!(file->f_mode & FMODE_WRITE)) return -EBADF; /* * We can only allow pure fallocate on append only files */ if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) return -EPERM; if (IS_IMMUTABLE(inode)) return -EPERM; /* * We cannot allow any fallocate operation on an active swapfile */ if (IS_SWAPFILE(inode)) return -ETXTBSY; /* * Revalidate the write permissions, in case security policy has * changed since the files were opened. */ ret = security_file_permission(file, MAY_WRITE); if (ret) return ret; if (S_ISFIFO(inode->i_mode)) return -ESPIPE; if (S_ISDIR(inode->i_mode)) return -EISDIR; if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) return -ENODEV; /* Check for wrap through zero too */ if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) return -EFBIG; if (!file->f_op->fallocate) return -EOPNOTSUPP; file_start_write(file); ret = file->f_op->fallocate(file, mode, offset, len); /* * Create inotify and fanotify events. * * To keep the logic simple always create events if fallocate succeeds. * This implies that events are even created if the file size remains * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE. */ if (ret == 0) fsnotify_modify(file); file_end_write(file); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Amit Arora13837.00%15.26%
Namjae Jeon4211.26%210.53%
Ankit Jain379.92%15.26%
Lukas Czerner359.38%315.79%
Darrick J. Wong328.58%210.53%
Marco Stornelli256.70%15.26%
Josef Bacik164.29%15.26%
Amir Goldstein133.49%210.53%
Heinrich Schuchardt123.22%15.26%
Jan Kara112.95%15.26%
Christoph Hellwig51.34%15.26%
Eric Biggers30.80%15.26%
Al Viro30.80%15.26%
Anna Schumaker10.27%15.26%
Total373100.00%19100.00%

EXPORT_SYMBOL_GPL(vfs_fallocate); SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len) { struct fd f = fdget(fd); int error = -EBADF; if (f.file) { error = vfs_fallocate(f.file, mode, offset, len); fdput(f); } return error; } /* * access() needs to use the real uid/gid, not the effective uid/gid. * We do this by temporarily clearing all FS-related capabilities and * switching the fsuid/fsgid around to the real ones. */ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) { const struct cred *old_cred; struct cred *override_cred; struct path path; struct inode *inode; int res; unsigned int lookup_flags = LOOKUP_FOLLOW; if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ return -EINVAL; override_cred = prepare_creds(); if (!override_cred) return -ENOMEM; override_cred->fsuid = override_cred->uid; override_cred->fsgid = override_cred->gid; if (!issecure(SECURE_NO_SETUID_FIXUP)) { /* Clear the capabilities if we switch to a non-root user */ kuid_t root_uid = make_kuid(override_cred->user_ns, 0); if (!uid_eq(override_cred->uid, root_uid)) cap_clear(override_cred->cap_effective); else override_cred->cap_effective = override_cred->cap_permitted; } old_cred = override_creds(override_cred); retry: res = user_path_at(dfd, filename, lookup_flags, &path); if (res) goto out; inode = d_backing_inode(path.dentry); if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { /* * MAY_EXEC on regular files is denied if the fs is mounted * with the "noexec" flag. */ res = -EACCES; if (path_noexec(&path)) goto out_path_release; } res = inode_permission(inode, mode | MAY_ACCESS); /* SuS v2 requires we report a read only fs too */ if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) goto out_path_release; /* * This is a rare case where using __mnt_is_readonly() * is OK without a mnt_want/drop_write() pair. Since * no actual write to the fs is performed here, we do * not need to telegraph to that to anyone. * * By doing this, we accept that this access is * inherently racy and know that the fs may change * state before we even see this result. */ if (__mnt_is_readonly(path.mnt)) res = -EROFS; out_path_release: path_put(&path); if (retry_estale(res, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: revert_creds(old_cred); put_cred(override_cred); return res; } SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) { return sys_faccessat(AT_FDCWD, filename, mode); } SYSCALL_DEFINE1(chdir, const char __user *, filename) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; retry: error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); if (error) goto out; error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; set_fs_pwd(current->fs, &path); dput_and_out: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: return error; } SYSCALL_DEFINE1(fchdir, unsigned int, fd) { struct fd f = fdget_raw(fd); struct inode *inode; int error = -EBADF; error = -EBADF; if (!f.file) goto out; inode = file_inode(f.file); error = -ENOTDIR; if (!S_ISDIR(inode->i_mode)) goto out_putf; error = inode_permission(inode, MAY_EXEC | MAY_CHDIR); if (!error) set_fs_pwd(current->fs, &f.file->f_path); out_putf: fdput(f); out: return error; } SYSCALL_DEFINE1(chroot, const char __user *, filename) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; retry: error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); if (error) goto out; error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); if (error) goto dput_and_out; error = -EPERM; if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) goto dput_and_out; error = security_path_chroot(&path); if (error) goto dput_and_out; set_fs_root(current->fs, &path); error = 0; dput_and_out: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: return error; }
static int chmod_common(const struct path *path, umode_t mode) { struct inode *inode = path->dentry->d_inode; struct inode *delegated_inode = NULL; struct iattr newattrs; int error; error = mnt_want_write(path->mnt); if (error) return error; retry_deleg: inode_lock(inode); error = security_path_chmod(path, mode); if (error) goto out_unlock; newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; error = notify_change(path->dentry, &newattrs, &delegated_inode); out_unlock: inode_unlock(inode); if (delegated_inode) { error = break_deleg_wait(&delegated_inode); if (!error) goto retry_deleg; } mnt_drop_write(path->mnt); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5433.75%952.94%
Al Viro5031.25%423.53%
J. Bruce Fields3421.25%15.88%
Tetsuo Handa1911.88%211.76%
Dave Hansen31.88%15.88%
Total160100.00%17100.00%

SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) { struct fd f = fdget(fd); int err = -EBADF; if (f.file) { audit_file(f.file); err = chmod_common(&f.file->f_path, mode); fdput(f); } return err; } SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW; retry: error = user_path_at(dfd, filename, lookup_flags, &path); if (!error) { error = chmod_common(&path, mode); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } } return error; } SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) { return sys_fchmodat(AT_FDCWD, filename, mode); }
static int chown_common(const struct path *path, uid_t user, gid_t group) { struct inode *inode = path->dentry->d_inode; struct inode *delegated_inode = NULL; int error; struct iattr newattrs; kuid_t uid; kgid_t gid; uid = make_kuid(current_user_ns(), user); gid = make_kgid(current_user_ns(), group); retry_deleg: newattrs.ia_valid = ATTR_CTIME; if (user != (uid_t) -1) { if (!uid_valid(uid)) return -EINVAL; newattrs.ia_valid |= ATTR_UID; newattrs.ia_uid = uid; } if (group != (gid_t) -1) { if (!gid_valid(gid)) return -EINVAL; newattrs.ia_valid |= ATTR_GID; newattrs.ia_gid = gid; } if (!S_ISDIR(inode->i_mode)) newattrs.ia_valid |= ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; inode_lock(inode); error = security_path_chown(path, uid, gid); if (!error) error = notify_change(path->dentry, &newattrs, &delegated_inode); inode_unlock(inode); if (delegated_inode) { error = break_deleg_wait(&delegated_inode); if (!error) goto retry_deleg; } return error; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8536.17%1352.00%
Eric W. Biedermann5422.98%28.00%
Al Viro3314.04%312.00%
J. Bruce Fields3213.62%14.00%
Tetsuo Handa208.51%14.00%
Miklos Szeredi41.70%14.00%
Linus Torvalds31.28%28.00%
Andrew Elble20.85%14.00%
Serge E. Hallyn20.85%14.00%
Total235100.00%25100.00%

SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, gid_t, group, int, flag) { struct path path; int error = -EINVAL; int lookup_flags; if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) goto out; lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; if (flag & AT_EMPTY_PATH) lookup_flags |= LOOKUP_EMPTY; retry: error = user_path_at(dfd, filename, lookup_flags, &path); if (error) goto out; error = mnt_want_write(path.mnt); if (error) goto out_release; error = chown_common(&path, user, group); mnt_drop_write(path.mnt); out_release: path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } out: return error; } SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) { return sys_fchownat(AT_FDCWD, filename, user, group, 0); } SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) { return sys_fchownat(AT_FDCWD, filename, user, group, AT_SYMLINK_NOFOLLOW); } SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) { struct fd f = fdget(fd); int error = -EBADF; if (!f.file) goto out; error = mnt_want_write_file(f.file); if (error) goto out_fput; audit_file(f.file); error = chown_common(&f.file->f_path, user, group); mnt_drop_write_file(f.file); out_fput: fdput(f); out: return error; }
int open_check_o_direct(struct file *f) { /* NB: we're sure to have correct a_ops only after f_op->open */ if (f->f_flags & O_DIRECT) { if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) return -EINVAL; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Miklos Szeredi46100.00%1100.00%
Total46100.00%1100.00%


static int do_dentry_open(struct file *f, struct inode *inode, int (*open)(struct inode *, struct file *), const struct cred *cred) { static const struct file_operations empty_fops = {}; int error; f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; path_get(&f->f_path); f->f_inode = inode; f->f_mapping = inode->i_mapping; if (unlikely(f->f_flags & O_PATH)) { f->f_mode = FMODE_PATH; f->f_op = &empty_fops; return 0; } if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { error = get_write_access(inode); if (unlikely(error)) goto cleanup_file; error = __mnt_want_write(f->f_path.mnt); if (unlikely(error)) { put_write_access(inode); goto cleanup_file; } f->f_mode |= FMODE_WRITER; } /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) f->f_mode |= FMODE_ATOMIC_POS; f->f_op = fops_get(inode->i_fop); if (unlikely(WARN_ON(!f->f_op))) { error = -ENODEV; goto cleanup_all; } error = security_file_open(f, cred); if (error) goto cleanup_all; error = break_lease(locks_inode(f), f->f_flags); if (error) goto cleanup_all; if (!open) open = f->f_op->open; if (open) { error = open(inode, f); if (error) goto cleanup_all; } if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) i_readcount_inc(inode); if ((f->f_mode & FMODE_READ) && likely(f->f_op->read || f->f_op->read_iter)) f->f_mode |= FMODE_CAN_READ; if ((f->f_mode & FMODE_WRITE) && likely(f->f_op->write || f->f_op->write_iter)) f->f_mode |= FMODE_CAN_WRITE; f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); return 0; cleanup_all: fops_put(f->f_op); if (f->f_mode & FMODE_WRITER) { put_write_access(inode); __mnt_drop_write(f->f_path.mnt); } cleanup_file: path_put(&f->f_path); f->f_path.mnt = NULL; f->f_path.dentry = NULL; f->f_inode = NULL; return error; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro21843.69%1833.96%
Linus Torvalds (pre-git)12324.65%1732.08%
Trond Myklebust244.81%11.89%
Linus Torvalds224.41%35.66%
Andrew Morton193.81%23.77%
Dave Hansen183.61%23.77%
Mimi Zohar183.61%11.89%
J. Bruce Fields173.41%11.89%
David Howells142.81%23.77%
Yuichi Nakamura132.61%11.89%
Miklos Szeredi51.00%23.77%
Josef 'Jeff' Sipek40.80%11.89%
Peter Staubach30.60%11.89%
Eric Paris10.20%11.89%
Total499100.00%53100.00%

/** * finish_open - finish opening a file * @file: file pointer * @dentry: pointer to dentry * @open: open callback * @opened: state of open * * This can be used to finish opening a file passed to i_op->atomic_open(). * * If the open callback is set to NULL, then the standard f_op->open() * filesystem callback is substituted. * * NB: the dentry reference is _not_ consumed. If, for example, the dentry is * the return value of d_splice_alias(), then the caller needs to perform dput() * on it after finish_open(). * * On successful return @file is a fully instantiated open file. After this, if * an error occurs in ->atomic_open(), it needs to clean up with fput(). * * Returns zero on success or -errno if the open failed. */
int finish_open(struct file *file, struct dentry *dentry, int (*open)(struct inode *, struct file *), int *opened) { int error; BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ file->f_path.dentry = dentry; error = do_dentry_open(file, d_backing_inode(dentry), open, current_cred()); if (!error) *opened |= FILE_OPENED; return error; }

Contributors

PersonTokensPropCommitsCommitProp
Miklos Szeredi4654.76%114.29%
Al Viro3339.29%571.43%
David Howells55.95%114.29%
Total84100.00%7100.00%

EXPORT_SYMBOL(finish_open); /** * finish_no_open - finish ->atomic_open() without opening the file * * @file: file pointer * @dentry: dentry or NULL (as returned from ->lookup()) * * This can be used to set the result of a successful lookup in ->atomic_open(). * * NB: unlike finish_open() this function does consume the dentry reference and * the caller need not dput() it. * * Returns "1" which must be the return value of ->atomic_open() after having * called this function. */
int finish_no_open(struct file *file, struct dentry *dentry) { file->f_path.dentry = dentry; return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Miklos Szeredi1661.54%125.00%
Al Viro1038.46%375.00%
Total26100.00%4100.00%

EXPORT_SYMBOL(finish_no_open);
char *file_path(struct file *filp, char *buf, int buflen) { return d_path(&filp->f_path, buf, buflen); }

Contributors

PersonTokensPropCommitsCommitProp
Miklos Szeredi31100.00%1100.00%
Total31100.00%1100.00%

EXPORT_SYMBOL(file_path); /** * vfs_open - open the file at the given path * @path: path to open * @file: newly allocated file with f_flag initialized * @cred: credentials to use */
int vfs_open(const struct path *path, struct file *file, const struct cred *cred) { struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags); if (IS_ERR(dentry)) return PTR_ERR(dentry); file->f_path = *path; return do_dentry_open(file, d_backing_inode(dentry), NULL, cred); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells5573.33%133.33%
Miklos Szeredi2026.67%266.67%
Total75100.00%3100.00%


struct file *dentry_open(const struct path *path, int flags, const struct cred *cred) { int error; struct file *f; validate_creds(cred); /* We must always pass in a valid mount pointer. */ BUG_ON(!path->mnt); f = get_empty_filp(); if (!IS_ERR(f)) { f->f_flags = flags; error = vfs_open(path, f, cred); if (!error) { /* from now on we need fput() to dispose of f */ error = open_check_o_direct(f); if (error) { fput(f); f = ERR_PTR(error); } } else { put_filp(f); f = ERR_PTR(error); } } return f; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro7055.12%436.36%
Peter Staubach3325.98%19.09%
David Howells1310.24%218.18%
Christoph Hellwig43.15%19.09%
Miklos Szeredi32.36%19.09%
Tetsuo Handa32.36%19.09%
Trond Myklebust10.79%19.09%
Total127100.00%11100.00%

EXPORT_SYMBOL(dentry_open);
static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op) { int lookup_flags = 0; int acc_mode = ACC_MODE(flags); if (flags & (O_CREAT | __O_TMPFILE)) op->mode = (mode & S_IALLUGO) | S_IFREG; else op->mode = 0; /* Must never be set by userspace */ flags &= ~FMODE_NONOTIFY & ~O_CLOEXEC; /* * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only * check for O_DSYNC if the need any syncing at all we enforce it's * always set instead of having to deal with possibly weird behaviour * for malicious applications setting only __O_SYNC. */ if (flags & __O_SYNC) flags |= O_DSYNC; if (flags & __O_TMPFILE) { if ((flags & O_TMPFILE_MASK) != O_TMPFILE) return -EINVAL; if (!(acc_mode & MAY_WRITE)) return -EINVAL; } else if (flags & O_PATH) { /* * If we have O_PATH in the open flag. Then we * cannot have anything other than the below set of flags */ flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; acc_mode = 0; } op->open_flag = flags; /* O_TRUNC implies we need access checks for write permissions */ if (flags & O_TRUNC) acc_mode |= MAY_WRITE; /* Allow the LSM permission hook to distinguish append access from general write access. */ if (flags & O_APPEND) acc_mode |= MAY_APPEND; op->acc_mode = acc_mode; op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; if (flags & O_CREAT) { op->intent |= LOOKUP_CREATE; if (flags & O_EXCL) op->intent |= LOOKUP_EXCL; } if (flags & O_DIRECTORY) lookup_flags |= LOOKUP_DIRECTORY; if (!(flags & O_NOFOLLOW)) lookup_flags |= LOOKUP_FOLLOW; op->lookup_flags = lookup_flags; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro22693.78%981.82%
Miklos Szeredi114.56%19.09%
Andrew Lutomirski41.66%19.09%
Total241100.00%11100.00%

/** * file_open_name - open file and return file pointer * * @name: struct filename containing path to open * @flags: open flags as per the open(2) second argument * @mode: mode for the new file if O_CREAT is set, else ignored * * This is the helper to open a file from kernelspace if you really * have to. But in generally you should not do this, so please move * along, nothing to see here.. */
struct file *file_open_name(struct filename *name, int flags, umode_t mode) { struct open_flags op; int err = build_open_flags(flags, mode, &op); return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op); }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro4890.57%375.00%
Jeff Layton59.43%125.00%
Total53100.00%4100.00%

/** * filp_open - open file and return file pointer * * @filename: path to open * @flags: open flags as per the open(2) second argument * @mode: mode for the new file if O_CREAT is set, else ignored * * This is the helper to open a file from kernelspace if you really * have to. But in generally you should not do this, so please move * along, nothing to see here.. */
struct file *filp_open(const char *filename, int flags, umode_t mode) { struct filename *name = getname_kernel(filename); struct file *file = ERR_CAST(name); if (!IS_ERR(name)) { file = file_open_name(name, flags, mode); putname(name); } return file; }

Contributors

PersonTokensPropCommitsCommitProp
Paul Moore3450.75%150.00%
Jeff Layton3349.25%150.00%
Total67100.00%2100.00%

EXPORT_SYMBOL(filp_open);
struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, const char *filename, int flags, umode_t mode) { struct open_flags op; int err = build_open_flags(flags, mode, &op); if (err) return ERR_PTR(err); return do_file_open_root(dentry, mnt, filename, &op); }

Contributors

PersonTokensPropCommitsCommitProp
Al Viro6494.12%266.67%
Jann Horn45.88%133.33%
Total68100.00%3100.00%

EXPORT_SYMBOL(file_open_root);
struct file *filp_clone_open(struct file *oldfile) { struct file *file; int retval; file = get_empty_filp(); if (IS_ERR(file)) return file; file->f_flags = oldfile->f_flags; retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred); if (retval) { put_filp(file); return ERR_PTR(retval); } return file; }

Contributors

PersonTokensPropCommitsCommitProp
James Bottomley79100.00%1100.00%
Total79100.00%1100.00%

EXPORT_SYMBOL(filp_clone_open);
long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) { struct open_flags op; int fd = build_open_flags(flags, mode, &op); struct filename *tmp; if (fd) return fd; tmp = getname(filename); if (IS_ERR(tmp)) return PTR_ERR(tmp); fd = get_unused_fd_flags(flags); if (fd >= 0) { struct file *f = do_filp_open(dfd, tmp, &op); if (IS_ERR(f)) { put_unused_fd(fd); fd = PTR_ERR(f); } else { fsnotify_open(f); fd_install(fd, f); } } putname(tmp); return fd; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6948.25%741.18%
Al Viro3725.87%317.65%
Telemaque Ndizihiwe1711.89%15.88%
Ulrich Drepper106.99%211.76%
Robert Love53.50%15.88%
Jeff Layton21.40%15.88%
Miklos Szeredi21.40%15.88%
Linus Torvalds10.70%15.88%
Total143100.00%17100.00%

SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) { if (force_o_largefile()) flags |= O_LARGEFILE; return do_sys_open(AT_FDCWD, filename, flags, mode); } SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode) { if (force_o_largefile()) flags |= O_LARGEFILE; return do_sys_open(dfd, filename, flags, mode); } #ifndef __alpha__ /* * For backward compatibility? Maybe this should be moved * into arch/i386 instead? */ SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) { return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); } #endif /* * "id" is the POSIX thread ID. We use the * files pointer for this.. */
int filp_close(struct file *filp, fl_owner_t id) { int retval = 0; if (!file_count(filp)) { printk(KERN_ERR "VFS: Close: file count is 0\n"); return 0; } if (filp->f_op->flush) retval = filp->f_op->flush(filp, id); if (likely(!(filp->f_mode & FMODE_PATH))) { dnotify_flush(filp, id); locks_remove_posix(filp, id); } fput(filp); return retval; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6870.83%960.00%
Al Viro1616.67%16.67%
Christoph Lameter55.21%16.67%
Miklos Szeredi22.08%16.67%
Stephen Rothwell22.08%16.67%
Andrew Morton22.08%16.67%
Linus Torvalds11.04%16.67%
Total96100.00%15100.00%

EXPORT_SYMBOL(filp_close); /* * Careful here! We test whether the file pointer is NULL before * releasing the fd. This ensures that one clone task can't release * an fd while another clone is opening it. */ SYSCALL_DEFINE1(close, unsigned int, fd) { int retval = __close_fd(current->files, fd); /* can't restart close syscall because file table entry was cleared */ if (unlikely(retval == -ERESTARTSYS || retval == -ERESTARTNOINTR || retval == -ERESTARTNOHAND || retval == -ERESTART_RESTARTBLOCK)) retval = -EINTR; return retval; } EXPORT_SYMBOL(sys_close); /* * This routine simulates a hangup on the tty, to arrange that users * are given clean terminals at login time. */ SYSCALL_DEFINE0(vhangup) { if (capable(CAP_SYS_TTY_CONFIG)) { tty_vhangup_self(); return 0; } return -EPERM; } /* * Called when an inode is about to be open. * We use this to disallow opening large files on 32bit systems if * the caller didn't specify O_LARGEFILE. On 64bit systems we force * on this flag in sys_open. */
int generic_file_open(struct inode * inode, struct file * filp) { if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) return -EOVERFLOW; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds3690.00%133.33%
Andrew Morton37.50%133.33%
Alan Cox12.50%133.33%
Total40100.00%3100.00%

EXPORT_SYMBOL(generic_file_open); /* * This is used by subsystems that don't want seekable * file descriptors. The function is not supposed to ever fail, the only * reason it returns an 'int' and not 'void' is so that it can be plugged * directly into file_operations structure. */
int nonseekable_open(struct inode *inode, struct file *filp) { filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds31100.00%1100.00%
Total31100.00%1100.00%

EXPORT_SYMBOL(nonseekable_open);

Overall Contributors

PersonTokensPropCommitsCommitProp
Al Viro120124.12%6221.91%
Linus Torvalds (pre-git)118723.84%7727.21%
Miklos Szeredi2925.86%144.95%
David Howells2605.22%93.18%
Heiko Carstens2274.56%93.18%
Jeff Layton2134.28%82.83%
Linus Torvalds1613.23%124.24%
Amit Arora1492.99%10.35%
Ulrich Drepper1372.75%20.71%
Dave Hansen1202.41%62.12%
J. Bruce Fields861.73%20.71%
James Bottomley841.69%10.35%
Eric W. Biedermann801.61%51.77%
Tetsuo Handa771.55%41.41%
Ankit Jain631.27%10.35%
Namjae Jeon420.84%20.71%
Peter Staubach390.78%20.71%
Jan Kara360.72%20.71%
Andrew Morton360.72%93.18%
Lukas Czerner350.70%31.06%
Ernie Petrides350.70%10.35%
Paul Moore340.68%10.35%
Darrick J. Wong320.64%20.71%
Kentaro Takeda270.54%10.35%
Trond Myklebust260.52%20.71%
Jan Blunck260.52%31.06%
Marco Stornelli250.50%10.35%
Mimi Zohar180.36%10.35%
Andrew G. Morgan170.34%10.35%
Telemaque Ndizihiwe170.34%10.35%
Américo Wang170.34%10.35%
Josef Bacik160.32%10.35%
Arnaldo Carvalho de Melo150.30%10.35%
Christoph Hellwig150.30%41.41%
Amir Goldstein130.26%20.71%
Yuichi Nakamura130.26%10.35%
Heinrich Schuchardt120.24%10.35%
Eric Paris100.20%41.41%
Neil Brown80.16%10.35%
Anna Schumaker70.14%10.35%
Josef 'Jeff' Sipek70.14%10.35%
David M. Richter70.14%10.35%
Amy Griffis60.12%10.35%
Robert Love60.12%10.35%
Christoph Lameter50.10%10.35%
Jann Horn40.08%10.35%
Dipankar Sarma40.08%10.35%
Andrew Lutomirski40.08%10.35%
Arnd Bergmann30.06%10.35%
Yoav Zach30.06%10.35%
Alan Cox30.06%20.71%
Eric Biggers30.06%10.35%
Tejun Heo30.06%10.35%
Randy Dunlap30.06%10.35%
Stephen D. Smalley30.06%10.35%
Serge E. Hallyn20.04%10.35%
Andrew Elble20.04%10.35%
Stephen Rothwell20.04%10.35%
Dmitry Torokhov10.02%10.35%
Nicholas Piggin10.02%10.35%
Total4980100.00%283100.00%
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