X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fopen.c;h=baffc084580da4adc584d6d54b42e493a454cb38;hb=e4543eddfd3bf3e0d625841377fa695a519edfd4;hp=4ee2dcc31c285dc57c6922b21e1bad80e740b6c3;hpb=64e47488c913ac704d465a6af86a26786d1412a5;p=linux-2.6 diff --git a/fs/open.c b/fs/open.c index 4ee2dcc31c..baffc08458 100644 --- a/fs/open.c +++ b/fs/open.c @@ -24,6 +24,7 @@ #include #include #include +#include #include @@ -193,7 +194,7 @@ out: return error; } -int do_truncate(struct dentry *dentry, loff_t length) +int do_truncate(struct dentry *dentry, loff_t length, struct file *filp) { int err; struct iattr newattrs; @@ -204,6 +205,10 @@ int do_truncate(struct dentry *dentry, loff_t length) newattrs.ia_size = length; newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; + if (filp) { + newattrs.ia_file = filp; + newattrs.ia_valid |= ATTR_FILE; + } down(&dentry->d_inode->i_sem); err = notify_change(dentry, &newattrs); @@ -235,7 +240,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length) if (!S_ISREG(inode->i_mode)) goto dput_and_out; - error = permission(inode,MAY_WRITE,&nd); + error = vfs_permission(&nd, MAY_WRITE); if (error) goto dput_and_out; @@ -261,7 +266,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length) error = locks_verify_truncate(inode, NULL, length); if (!error) { DQUOT_INIT(inode); - error = do_truncate(nd.dentry, length); + error = do_truncate(nd.dentry, length, NULL); } put_write_access(inode); @@ -313,7 +318,7 @@ static inline long do_sys_ftruncate(unsigned int fd, loff_t length, int small) error = locks_verify_truncate(inode, file, length); if (!error) - error = do_truncate(dentry, length); + error = do_truncate(dentry, length, file); out_putf: fput(file); out: @@ -389,7 +394,7 @@ asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) goto dput_and_out; if (current->fsuid != inode->i_uid && - (error = permission(inode,MAY_WRITE,&nd)) != 0) + (error = vfs_permission(&nd, MAY_WRITE)) != 0) goto dput_and_out; } down(&inode->i_sem); @@ -442,7 +447,7 @@ long do_utimes(char __user * filename, struct timeval * times) goto dput_and_out; if (current->fsuid != inode->i_uid && - (error = permission(inode,MAY_WRITE,&nd)) != 0) + (error = vfs_permission(&nd, MAY_WRITE)) != 0) goto dput_and_out; } down(&inode->i_sem); @@ -501,7 +506,7 @@ asmlinkage long sys_access(const char __user * filename, int mode) res = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); if (!res) { - res = permission(nd.dentry->d_inode, mode, &nd); + res = vfs_permission(&nd, mode); /* SuS v2 requires we report a read only fs too */ if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode) && !special_file(nd.dentry->d_inode->i_mode)) @@ -525,7 +530,7 @@ asmlinkage long sys_chdir(const char __user * filename) if (error) goto out; - error = permission(nd.dentry->d_inode,MAY_EXEC,&nd); + error = vfs_permission(&nd, MAY_EXEC); if (error) goto dput_and_out; @@ -576,7 +581,7 @@ asmlinkage long sys_chroot(const char __user * filename) if (error) goto out; - error = permission(nd.dentry->d_inode,MAY_EXEC,&nd); + error = vfs_permission(&nd, MAY_EXEC); if (error) goto dput_and_out; @@ -737,52 +742,16 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) return error; } -/* - * Note that while the flag value (low two bits) for sys_open means: - * 00 - read-only - * 01 - write-only - * 10 - read-write - * 11 - special - * it is changed into - * 00 - no permissions needed - * 01 - read-permission - * 10 - write-permission - * 11 - read-write - * for the internal routines (ie open_namei()/follow_link() etc). 00 is - * used by symlinks. - */ -struct file *filp_open(const char * filename, int flags, int mode) -{ - int namei_flags, error; - struct nameidata nd; - - namei_flags = flags; - if ((namei_flags+1) & O_ACCMODE) - namei_flags++; - if (namei_flags & O_TRUNC) - namei_flags |= 2; - - error = open_namei(filename, namei_flags, mode, &nd); - if (!error) - return dentry_open(nd.dentry, nd.mnt, flags); - - return ERR_PTR(error); -} - -EXPORT_SYMBOL(filp_open); - -struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) +static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, + int flags, struct file *f, + int (*open)(struct inode *, struct file *)) { - struct file * f; struct inode *inode; int error; - error = -ENFILE; - f = get_empty_filp(); - if (!f) - goto cleanup_dentry; f->f_flags = flags; - f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; + f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | + FMODE_PREAD | FMODE_PWRITE; inode = dentry->d_inode; if (f->f_mode & FMODE_WRITE) { error = get_write_access(inode); @@ -797,11 +766,14 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) f->f_op = fops_get(inode->i_fop); file_move(f, &inode->i_sb->s_files); - if (f->f_op && f->f_op->open) { - error = f->f_op->open(inode,f); + if (!open && f->f_op) + open = f->f_op->open; + if (open) { + error = open(inode, f); if (error) goto cleanup_all; } + f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); @@ -827,12 +799,117 @@ cleanup_all: f->f_vfsmnt = NULL; cleanup_file: put_filp(f); -cleanup_dentry: dput(dentry); mntput(mnt); return ERR_PTR(error); } +/* + * Note that while the flag value (low two bits) for sys_open means: + * 00 - read-only + * 01 - write-only + * 10 - read-write + * 11 - special + * it is changed into + * 00 - no permissions needed + * 01 - read-permission + * 10 - write-permission + * 11 - read-write + * for the internal routines (ie open_namei()/follow_link() etc). 00 is + * used by symlinks. + */ +struct file *filp_open(const char * filename, int flags, int mode) +{ + int namei_flags, error; + struct nameidata nd; + + namei_flags = flags; + if ((namei_flags+1) & O_ACCMODE) + namei_flags++; + + error = open_namei(filename, namei_flags, mode, &nd); + if (!error) + return nameidata_to_filp(&nd, flags); + + return ERR_PTR(error); +} +EXPORT_SYMBOL(filp_open); + +/** + * lookup_instantiate_filp - instantiates the open intent filp + * @nd: pointer to nameidata + * @dentry: pointer to dentry + * @open: open callback + * + * Helper for filesystems that want to use lookup open intents and pass back + * a fully instantiated struct file to the caller. + * This function is meant to be called from within a filesystem's + * lookup method. + * Note that in case of error, nd->intent.open.file is destroyed, but the + * path information remains valid. + * If the open callback is set to NULL, then the standard f_op->open() + * filesystem callback is substituted. + */ +struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, + int (*open)(struct inode *, struct file *)) +{ + if (IS_ERR(nd->intent.open.file)) + goto out; + if (IS_ERR(dentry)) + goto out_err; + nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt), + nd->intent.open.flags - 1, + nd->intent.open.file, + open); +out: + return nd->intent.open.file; +out_err: + release_open_intent(nd); + nd->intent.open.file = (struct file *)dentry; + goto out; +} +EXPORT_SYMBOL_GPL(lookup_instantiate_filp); + +/** + * nameidata_to_filp - convert a nameidata to an open filp. + * @nd: pointer to nameidata + * @flags: open flags + * + * Note that this function destroys the original nameidata + */ +struct file *nameidata_to_filp(struct nameidata *nd, int flags) +{ + struct file *filp; + + /* Pick up the filp from the open intent */ + filp = nd->intent.open.file; + /* Has the filesystem initialised the file for us? */ + if (filp->f_dentry == NULL) + filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL); + else + path_release(nd); + return filp; +} + +/* + * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an + * error. + */ +struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) +{ + int error; + struct file *f; + + error = -ENFILE; + f = get_empty_filp(); + if (f == NULL) { + dput(dentry); + mntput(mnt); + return ERR_PTR(error); + } + + return __dentry_open(dentry, mnt, flags, f, NULL); +} EXPORT_SYMBOL(dentry_open); /* @@ -842,14 +919,16 @@ int get_unused_fd(void) { struct files_struct * files = current->files; int fd, error; + struct fdtable *fdt; error = -EMFILE; spin_lock(&files->file_lock); repeat: - fd = find_next_zero_bit(files->open_fds->fds_bits, - files->max_fdset, - files->next_fd); + fdt = files_fdtable(files); + fd = find_next_zero_bit(fdt->open_fds->fds_bits, + fdt->max_fdset, + fdt->next_fd); /* * N.B. For clone tasks sharing a files structure, this test @@ -872,14 +951,14 @@ repeat: goto repeat; } - FD_SET(fd, files->open_fds); - FD_CLR(fd, files->close_on_exec); - files->next_fd = fd + 1; + FD_SET(fd, fdt->open_fds); + FD_CLR(fd, fdt->close_on_exec); + fdt->next_fd = fd + 1; #if 1 /* Sanity check */ - if (files->fd[fd] != NULL) { + if (fdt->fd[fd] != NULL) { printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); - files->fd[fd] = NULL; + fdt->fd[fd] = NULL; } #endif error = fd; @@ -893,9 +972,10 @@ EXPORT_SYMBOL(get_unused_fd); static inline void __put_unused_fd(struct files_struct *files, unsigned int fd) { - __FD_CLR(fd, files->open_fds); - if (fd < files->next_fd) - files->next_fd = fd; + struct fdtable *fdt = files_fdtable(files); + __FD_CLR(fd, fdt->open_fds); + if (fd < fdt->next_fd) + fdt->next_fd = fd; } void fastcall put_unused_fd(unsigned int fd) @@ -924,10 +1004,11 @@ EXPORT_SYMBOL(put_unused_fd); void fastcall fd_install(unsigned int fd, struct file * file) { struct files_struct *files = current->files; + struct fdtable *fdt; spin_lock(&files->file_lock); - if (unlikely(files->fd[fd] != NULL)) - BUG(); - files->fd[fd] = file; + fdt = files_fdtable(files); + BUG_ON(fdt->fd[fd] != NULL); + rcu_assign_pointer(fdt->fd[fd], file); spin_unlock(&files->file_lock); } @@ -1010,15 +1091,17 @@ asmlinkage long sys_close(unsigned int fd) { struct file * filp; struct files_struct *files = current->files; + struct fdtable *fdt; spin_lock(&files->file_lock); - if (fd >= files->max_fds) + fdt = files_fdtable(files); + if (fd >= fdt->max_fds) goto out_unlock; - filp = files->fd[fd]; + filp = fdt->fd[fd]; if (!filp) goto out_unlock; - files->fd[fd] = NULL; - FD_CLR(fd, files->close_on_exec); + rcu_assign_pointer(fdt->fd[fd], NULL); + FD_CLR(fd, fdt->close_on_exec); __put_unused_fd(files, fd); spin_unlock(&files->file_lock); return filp_close(filp, files);