diff options
Diffstat (limited to 'fs/ext4/file.c')
-rw-r--r-- | fs/ext4/file.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c new file mode 100644 index 00000000..cb70f181 --- /dev/null +++ b/fs/ext4/file.c @@ -0,0 +1,262 @@ +/* + * 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 <linux/quotaops.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_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) { + ext4_alloc_da_blocks(inode); + ext4_clear_inode_state(inode, 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 void ext4_aiodio_wait(struct inode *inode) +{ + wait_queue_head_t *wq = ext4_ioend_wq(inode); + + wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_aiodio_unwritten) == 0)); +} + +/* + * This tests whether the IO in question is block-aligned or not. + * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they + * are converted to written only after the IO is complete. Until they are + * mapped, these blocks appear as holes, so dio_zero_block() will assume that + * it needs to zero out portions of the start and/or end block. If 2 AIO + * threads are at work on the same unwritten block, they must be synchronized + * or one thread will zero the other's data, causing corruption. + */ +static int +ext4_unaligned_aio(struct inode *inode, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct super_block *sb = inode->i_sb; + int blockmask = sb->s_blocksize - 1; + size_t count = iov_length(iov, nr_segs); + loff_t final_size = pos + count; + + if (pos >= inode->i_size) + return 0; + + if ((pos & blockmask) || (final_size & blockmask)) + return 1; + + return 0; +} + +static ssize_t +ext4_file_write(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; + int unaligned_aio = 0; + int ret; + + /* + * If we have encountered a bitmap-format file, the size limit + * is smaller than s_maxbytes, which is for extent-mapped files. + */ + + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + size_t length = iov_length(iov, nr_segs); + + if ((pos > sbi->s_bitmap_maxbytes || + (pos == sbi->s_bitmap_maxbytes && length > 0))) + return -EFBIG; + + if (pos + length > sbi->s_bitmap_maxbytes) { + nr_segs = iov_shorten((struct iovec *)iov, nr_segs, + sbi->s_bitmap_maxbytes - pos); + } + } else if (unlikely((iocb->ki_filp->f_flags & O_DIRECT) && + !is_sync_kiocb(iocb))) { + unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos); + } + + /* Unaligned direct AIO must be serialized; see comment above */ + if (unaligned_aio) { + static unsigned long unaligned_warn_time; + + /* Warn about this once per day */ + if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ)) + ext4_msg(inode->i_sb, KERN_WARNING, + "Unaligned AIO/DIO on inode %ld by %s; " + "performance will be poor.", + inode->i_ino, current->comm); + mutex_lock(ext4_aio_mutex(inode)); + ext4_aiodio_wait(inode); + } + + ret = generic_file_aio_write(iocb, iov, nr_segs, pos); + + if (unaligned_aio) + mutex_unlock(ext4_aio_mutex(inode)); + + return ret; +} + +static const 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 ext4_inode_info *ei = EXT4_I(inode); + 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; + path.dentry = mnt->mnt_root; + cp = d_path(&path, buf, sizeof(buf)); + if (!IS_ERR(cp)) { + strlcpy(sbi->s_es->s_last_mounted, cp, + sizeof(sbi->s_es->s_last_mounted)); + ext4_mark_super_dirty(sb); + } + } + /* + * Set up the jbd2_inode if we are opening the inode for + * writing and the journal is present + */ + if (sbi->s_journal && !ei->jinode && (filp->f_mode & FMODE_WRITE)) { + struct jbd2_inode *jinode = jbd2_alloc_inode(GFP_KERNEL); + + spin_lock(&inode->i_lock); + if (!ei->jinode) { + if (!jinode) { + spin_unlock(&inode->i_lock); + return -ENOMEM; + } + ei->jinode = jinode; + jbd2_journal_init_jbd_inode(ei->jinode, inode); + jinode = NULL; + } + spin_unlock(&inode->i_lock); + if (unlikely(jinode != NULL)) + jbd2_free_inode(jinode); + } + return dquot_file_open(inode, filp); +} + +/* + * ext4_llseek() copied from generic_file_llseek() to handle both + * block-mapped and extent-mapped maxbytes values. This should + * otherwise be identical with generic_file_llseek(). + */ +loff_t ext4_llseek(struct file *file, loff_t offset, int origin) +{ + struct inode *inode = file->f_mapping->host; + loff_t maxbytes; + + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; + else + maxbytes = inode->i_sb->s_maxbytes; + + return generic_file_llseek_size(file, offset, origin, maxbytes); +} + +const struct file_operations ext4_file_operations = { + .llseek = ext4_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, + .fallocate = ext4_fallocate, +}; + +const struct inode_operations ext4_file_inode_operations = { + .setattr = ext4_setattr, + .getattr = ext4_getattr, +#ifdef CONFIG_EXT4_FS_XATTR + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, + .listxattr = ext4_listxattr, + .removexattr = generic_removexattr, +#endif + .get_acl = ext4_get_acl, + .fiemap = ext4_fiemap, +}; + |