/* * linux/fs/ext4/file.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/file.c * * Copyright (C) 1991, 1992 Linus Torvalds * * ext4 fs regular file handling primitives * * 64-bit file support on 64-bit platforms by Jakub Jelinek * (jj@sunsite.ms.mff.cuni.cz) */ #include <linux/time.h> #include <linux/fs.h> #include <linux/jbd2.h> #include "ext4.h" #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" /* * Called when an inode is released. Note that this is different * from ext4_file_open: open gets called at every open, but release * gets called only when /all/ the files are closed. */ static int ext4_release_file(struct inode *inode, struct file *filp) { /* if we are the last writer on the inode, drop the block reservation */ if ((filp->f_mode & FMODE_WRITE) && (atomic_read(&inode->i_writecount) == 1)) { down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_reservation(inode); up_write(&EXT4_I(inode)->i_data_sem); } if (is_dx(inode) && filp->private_data) ext4_htree_free_dir_info(filp->private_data); return 0; } static ssize_t ext4_file_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_path.dentry->d_inode; ssize_t ret; int err; /* * If we have encountered a bitmap-format file, the size limit * is smaller than s_maxbytes, which is for extent-mapped files. */ if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); size_t length = iov_length(iov, nr_segs); if (pos > sbi->s_bitmap_maxbytes) return -EFBIG; if (pos + length > sbi->s_bitmap_maxbytes) { nr_segs = iov_shorten((struct iovec *)iov, nr_segs, sbi->s_bitmap_maxbytes - pos); } } ret = generic_file_aio_write(iocb, iov, nr_segs, pos); /* * Skip flushing if there was an error, or if nothing was written. */ if (ret <= 0) return ret; /* * If the inode is IS_SYNC, or is O_SYNC and we are doing data * journalling then we need to make sure that we force the transaction * to disk to keep all metadata uptodate synchronously. */ if (file->f_flags & O_SYNC) { /* * If we are non-data-journaled, then the dirty data has * already been flushed to backing store by generic_osync_inode, * and the inode has been flushed too if there have been any * modifications other than mere timestamp updates. * * Open question --- do we care about flushing timestamps too * if the inode is IS_SYNC? */ if (!ext4_should_journal_data(inode)) return ret; goto force_commit; } /* * So we know that there has been no forced data flush. If the inode * is marked IS_SYNC, we need to force one ourselves. */ if (!IS_SYNC(inode)) return ret; /* * Open question #2 --- should we force data to disk here too? If we * don't, the only impact is that data=writeback filesystems won't * flush data to disk automatically on IS_SYNC, only metadata (but * historically, that is what ext2 has done.) */ force_commit: err = ext4_force_commit(inode->i_sb); if (err) return err; return ret; } static struct vm_operations_struct ext4_file_vm_ops = { .fault = filemap_fault, .page_mkwrite = ext4_page_mkwrite, }; static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) { struct address_space *mapping = file->f_mapping; if (!mapping->a_ops->readpage) return -ENOEXEC; file_accessed(file); vma->vm_ops = &ext4_file_vm_ops; vma->vm_flags |= VM_CAN_NONLINEAR; return 0; } const struct file_operations ext4_file_operations = { .llseek = generic_file_llseek, .read = do_sync_read, .write = do_sync_write, .aio_read = generic_file_aio_read, .aio_write = ext4_file_write, .unlocked_ioctl = ext4_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = ext4_compat_ioctl, #endif .mmap = ext4_file_mmap, .open = generic_file_open, .release = ext4_release_file, .fsync = ext4_sync_file, .splice_read = generic_file_splice_read, .splice_write = generic_file_splice_write, }; const struct inode_operations ext4_file_inode_operations = { .truncate = ext4_truncate, .setattr = ext4_setattr, .getattr = ext4_getattr, #ifdef CONFIG_EXT4DEV_FS_XATTR .setxattr = generic_setxattr, .getxattr = generic_getxattr, .listxattr = ext4_listxattr, .removexattr = generic_removexattr, #endif .permission = ext4_permission, .fallocate = ext4_fallocate, };