| /* |
| * 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 <linux/mount.h> |
| #include <linux/path.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 (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) { |
| ext4_alloc_da_blocks(inode); |
| EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE; |
| } |
| /* 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) && |
| !EXT4_I(inode)->i_reserved_data_blocks) |
| { |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_discard_preallocations(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; |
| } |
| |
| static int ext4_file_open(struct inode * inode, struct file * filp) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| struct vfsmount *mnt = filp->f_path.mnt; |
| struct path path; |
| char buf[64], *cp; |
| |
| if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) && |
| !(sb->s_flags & MS_RDONLY))) { |
| sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; |
| /* |
| * Sample where the filesystem has been mounted and |
| * store it in the superblock for sysadmin convenience |
| * when trying to sort through large numbers of block |
| * devices or filesystem images. |
| */ |
| memset(buf, 0, sizeof(buf)); |
| path.mnt = mnt->mnt_parent; |
| path.dentry = mnt->mnt_mountpoint; |
| path_get(&path); |
| cp = d_path(&path, buf, sizeof(buf)); |
| path_put(&path); |
| if (!IS_ERR(cp)) { |
| memcpy(sbi->s_es->s_last_mounted, cp, |
| sizeof(sbi->s_es->s_last_mounted)); |
| sb->s_dirt = 1; |
| } |
| } |
| return generic_file_open(inode, filp); |
| } |
| |
| 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 = ext4_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_EXT4_FS_XATTR |
| .setxattr = generic_setxattr, |
| .getxattr = generic_getxattr, |
| .listxattr = ext4_listxattr, |
| .removexattr = generic_removexattr, |
| #endif |
| .check_acl = ext4_check_acl, |
| .fallocate = ext4_fallocate, |
| .fiemap = ext4_fiemap, |
| }; |
| |