diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_file.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_file.c | 1091 | 
1 files changed, 0 insertions, 1091 deletions
| diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c deleted file mode 100644 index cca00f49e092..000000000000 --- a/fs/xfs/linux-2.6/xfs_file.c +++ /dev/null @@ -1,1091 +0,0 @@ -/* - * Copyright (c) 2000-2005 Silicon Graphics, Inc. - * All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it would be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write the Free Software Foundation, - * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA - */ -#include "xfs.h" -#include "xfs_fs.h" -#include "xfs_bit.h" -#include "xfs_log.h" -#include "xfs_inum.h" -#include "xfs_sb.h" -#include "xfs_ag.h" -#include "xfs_trans.h" -#include "xfs_mount.h" -#include "xfs_bmap_btree.h" -#include "xfs_alloc.h" -#include "xfs_dinode.h" -#include "xfs_inode.h" -#include "xfs_inode_item.h" -#include "xfs_bmap.h" -#include "xfs_error.h" -#include "xfs_vnodeops.h" -#include "xfs_da_btree.h" -#include "xfs_ioctl.h" -#include "xfs_trace.h" - -#include <linux/dcache.h> -#include <linux/falloc.h> - -static const struct vm_operations_struct xfs_file_vm_ops; - -/* - * Locking primitives for read and write IO paths to ensure we consistently use - * and order the inode->i_mutex, ip->i_lock and ip->i_iolock. - */ -static inline void -xfs_rw_ilock( -	struct xfs_inode	*ip, -	int			type) -{ -	if (type & XFS_IOLOCK_EXCL) -		mutex_lock(&VFS_I(ip)->i_mutex); -	xfs_ilock(ip, type); -} - -static inline void -xfs_rw_iunlock( -	struct xfs_inode	*ip, -	int			type) -{ -	xfs_iunlock(ip, type); -	if (type & XFS_IOLOCK_EXCL) -		mutex_unlock(&VFS_I(ip)->i_mutex); -} - -static inline void -xfs_rw_ilock_demote( -	struct xfs_inode	*ip, -	int			type) -{ -	xfs_ilock_demote(ip, type); -	if (type & XFS_IOLOCK_EXCL) -		mutex_unlock(&VFS_I(ip)->i_mutex); -} - -/* - *	xfs_iozero - * - *	xfs_iozero clears the specified range of buffer supplied, - *	and marks all the affected blocks as valid and modified.  If - *	an affected block is not allocated, it will be allocated.  If - *	an affected block is not completely overwritten, and is not - *	valid before the operation, it will be read from disk before - *	being partially zeroed. - */ -STATIC int -xfs_iozero( -	struct xfs_inode	*ip,	/* inode			*/ -	loff_t			pos,	/* offset in file		*/ -	size_t			count)	/* size of data to zero		*/ -{ -	struct page		*page; -	struct address_space	*mapping; -	int			status; - -	mapping = VFS_I(ip)->i_mapping; -	do { -		unsigned offset, bytes; -		void *fsdata; - -		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ -		bytes = PAGE_CACHE_SIZE - offset; -		if (bytes > count) -			bytes = count; - -		status = pagecache_write_begin(NULL, mapping, pos, bytes, -					AOP_FLAG_UNINTERRUPTIBLE, -					&page, &fsdata); -		if (status) -			break; - -		zero_user(page, offset, bytes); - -		status = pagecache_write_end(NULL, mapping, pos, bytes, bytes, -					page, fsdata); -		WARN_ON(status <= 0); /* can't return less than zero! */ -		pos += bytes; -		count -= bytes; -		status = 0; -	} while (count); - -	return (-status); -} - -STATIC int -xfs_file_fsync( -	struct file		*file, -	loff_t			start, -	loff_t			end, -	int			datasync) -{ -	struct inode		*inode = file->f_mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	struct xfs_mount	*mp = ip->i_mount; -	struct xfs_trans	*tp; -	int			error = 0; -	int			log_flushed = 0; - -	trace_xfs_file_fsync(ip); - -	error = filemap_write_and_wait_range(inode->i_mapping, start, end); -	if (error) -		return error; - -	if (XFS_FORCED_SHUTDOWN(mp)) -		return -XFS_ERROR(EIO); - -	xfs_iflags_clear(ip, XFS_ITRUNCATED); - -	xfs_ioend_wait(ip); - -	if (mp->m_flags & XFS_MOUNT_BARRIER) { -		/* -		 * If we have an RT and/or log subvolume we need to make sure -		 * to flush the write cache the device used for file data -		 * first.  This is to ensure newly written file data make -		 * it to disk before logging the new inode size in case of -		 * an extending write. -		 */ -		if (XFS_IS_REALTIME_INODE(ip)) -			xfs_blkdev_issue_flush(mp->m_rtdev_targp); -		else if (mp->m_logdev_targp != mp->m_ddev_targp) -			xfs_blkdev_issue_flush(mp->m_ddev_targp); -	} - -	/* -	 * We always need to make sure that the required inode state is safe on -	 * disk.  The inode might be clean but we still might need to force the -	 * log because of committed transactions that haven't hit the disk yet. -	 * Likewise, there could be unflushed non-transactional changes to the -	 * inode core that have to go to disk and this requires us to issue -	 * a synchronous transaction to capture these changes correctly. -	 * -	 * This code relies on the assumption that if the i_update_core field -	 * of the inode is clear and the inode is unpinned then it is clean -	 * and no action is required. -	 */ -	xfs_ilock(ip, XFS_ILOCK_SHARED); - -	/* -	 * First check if the VFS inode is marked dirty.  All the dirtying -	 * of non-transactional updates no goes through mark_inode_dirty*, -	 * which allows us to distinguish beteeen pure timestamp updates -	 * and i_size updates which need to be caught for fdatasync. -	 * After that also theck for the dirty state in the XFS inode, which -	 * might gets cleared when the inode gets written out via the AIL -	 * or xfs_iflush_cluster. -	 */ -	if (((inode->i_state & I_DIRTY_DATASYNC) || -	    ((inode->i_state & I_DIRTY_SYNC) && !datasync)) && -	    ip->i_update_core) { -		/* -		 * Kick off a transaction to log the inode core to get the -		 * updates.  The sync transaction will also force the log. -		 */ -		xfs_iunlock(ip, XFS_ILOCK_SHARED); -		tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS); -		error = xfs_trans_reserve(tp, 0, -				XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0); -		if (error) { -			xfs_trans_cancel(tp, 0); -			return -error; -		} -		xfs_ilock(ip, XFS_ILOCK_EXCL); - -		/* -		 * Note - it's possible that we might have pushed ourselves out -		 * of the way during trans_reserve which would flush the inode. -		 * But there's no guarantee that the inode buffer has actually -		 * gone out yet (it's delwri).	Plus the buffer could be pinned -		 * anyway if it's part of an inode in another recent -		 * transaction.	 So we play it safe and fire off the -		 * transaction anyway. -		 */ -		xfs_trans_ijoin(tp, ip); -		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); -		xfs_trans_set_sync(tp); -		error = _xfs_trans_commit(tp, 0, &log_flushed); - -		xfs_iunlock(ip, XFS_ILOCK_EXCL); -	} else { -		/* -		 * Timestamps/size haven't changed since last inode flush or -		 * inode transaction commit.  That means either nothing got -		 * written or a transaction committed which caught the updates. -		 * If the latter happened and the transaction hasn't hit the -		 * disk yet, the inode will be still be pinned.  If it is, -		 * force the log. -		 */ -		if (xfs_ipincount(ip)) { -			error = _xfs_log_force_lsn(mp, -					ip->i_itemp->ili_last_lsn, -					XFS_LOG_SYNC, &log_flushed); -		} -		xfs_iunlock(ip, XFS_ILOCK_SHARED); -	} - -	/* -	 * If we only have a single device, and the log force about was -	 * a no-op we might have to flush the data device cache here. -	 * This can only happen for fdatasync/O_DSYNC if we were overwriting -	 * an already allocated file and thus do not have any metadata to -	 * commit. -	 */ -	if ((mp->m_flags & XFS_MOUNT_BARRIER) && -	    mp->m_logdev_targp == mp->m_ddev_targp && -	    !XFS_IS_REALTIME_INODE(ip) && -	    !log_flushed) -		xfs_blkdev_issue_flush(mp->m_ddev_targp); - -	return -error; -} - -STATIC ssize_t -xfs_file_aio_read( -	struct kiocb		*iocb, -	const struct iovec	*iovp, -	unsigned long		nr_segs, -	loff_t			pos) -{ -	struct file		*file = iocb->ki_filp; -	struct inode		*inode = file->f_mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	struct xfs_mount	*mp = ip->i_mount; -	size_t			size = 0; -	ssize_t			ret = 0; -	int			ioflags = 0; -	xfs_fsize_t		n; -	unsigned long		seg; - -	XFS_STATS_INC(xs_read_calls); - -	BUG_ON(iocb->ki_pos != pos); - -	if (unlikely(file->f_flags & O_DIRECT)) -		ioflags |= IO_ISDIRECT; -	if (file->f_mode & FMODE_NOCMTIME) -		ioflags |= IO_INVIS; - -	/* START copy & waste from filemap.c */ -	for (seg = 0; seg < nr_segs; seg++) { -		const struct iovec *iv = &iovp[seg]; - -		/* -		 * If any segment has a negative length, or the cumulative -		 * length ever wraps negative then return -EINVAL. -		 */ -		size += iv->iov_len; -		if (unlikely((ssize_t)(size|iv->iov_len) < 0)) -			return XFS_ERROR(-EINVAL); -	} -	/* END copy & waste from filemap.c */ - -	if (unlikely(ioflags & IO_ISDIRECT)) { -		xfs_buftarg_t	*target = -			XFS_IS_REALTIME_INODE(ip) ? -				mp->m_rtdev_targp : mp->m_ddev_targp; -		if ((iocb->ki_pos & target->bt_smask) || -		    (size & target->bt_smask)) { -			if (iocb->ki_pos == ip->i_size) -				return 0; -			return -XFS_ERROR(EINVAL); -		} -	} - -	n = XFS_MAXIOFFSET(mp) - iocb->ki_pos; -	if (n <= 0 || size == 0) -		return 0; - -	if (n < size) -		size = n; - -	if (XFS_FORCED_SHUTDOWN(mp)) -		return -EIO; - -	if (unlikely(ioflags & IO_ISDIRECT)) { -		xfs_rw_ilock(ip, XFS_IOLOCK_EXCL); - -		if (inode->i_mapping->nrpages) { -			ret = -xfs_flushinval_pages(ip, -					(iocb->ki_pos & PAGE_CACHE_MASK), -					-1, FI_REMAPF_LOCKED); -			if (ret) { -				xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL); -				return ret; -			} -		} -		xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); -	} else -		xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); - -	trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags); - -	ret = generic_file_aio_read(iocb, iovp, nr_segs, iocb->ki_pos); -	if (ret > 0) -		XFS_STATS_ADD(xs_read_bytes, ret); - -	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); -	return ret; -} - -STATIC ssize_t -xfs_file_splice_read( -	struct file		*infilp, -	loff_t			*ppos, -	struct pipe_inode_info	*pipe, -	size_t			count, -	unsigned int		flags) -{ -	struct xfs_inode	*ip = XFS_I(infilp->f_mapping->host); -	int			ioflags = 0; -	ssize_t			ret; - -	XFS_STATS_INC(xs_read_calls); - -	if (infilp->f_mode & FMODE_NOCMTIME) -		ioflags |= IO_INVIS; - -	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) -		return -EIO; - -	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); - -	trace_xfs_file_splice_read(ip, count, *ppos, ioflags); - -	ret = generic_file_splice_read(infilp, ppos, pipe, count, flags); -	if (ret > 0) -		XFS_STATS_ADD(xs_read_bytes, ret); - -	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); -	return ret; -} - -STATIC void -xfs_aio_write_isize_update( -	struct inode	*inode, -	loff_t		*ppos, -	ssize_t		bytes_written) -{ -	struct xfs_inode	*ip = XFS_I(inode); -	xfs_fsize_t		isize = i_size_read(inode); - -	if (bytes_written > 0) -		XFS_STATS_ADD(xs_write_bytes, bytes_written); - -	if (unlikely(bytes_written < 0 && bytes_written != -EFAULT && -					*ppos > isize)) -		*ppos = isize; - -	if (*ppos > ip->i_size) { -		xfs_rw_ilock(ip, XFS_ILOCK_EXCL); -		if (*ppos > ip->i_size) -			ip->i_size = *ppos; -		xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); -	} -} - -/* - * If this was a direct or synchronous I/O that failed (such as ENOSPC) then - * part of the I/O may have been written to disk before the error occurred.  In - * this case the on-disk file size may have been adjusted beyond the in-memory - * file size and now needs to be truncated back. - */ -STATIC void -xfs_aio_write_newsize_update( -	struct xfs_inode	*ip) -{ -	if (ip->i_new_size) { -		xfs_rw_ilock(ip, XFS_ILOCK_EXCL); -		ip->i_new_size = 0; -		if (ip->i_d.di_size > ip->i_size) -			ip->i_d.di_size = ip->i_size; -		xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); -	} -} - -/* - * xfs_file_splice_write() does not use xfs_rw_ilock() because - * generic_file_splice_write() takes the i_mutex itself. This, in theory, - * couuld cause lock inversions between the aio_write path and the splice path - * if someone is doing concurrent splice(2) based writes and write(2) based - * writes to the same inode. The only real way to fix this is to re-implement - * the generic code here with correct locking orders. - */ -STATIC ssize_t -xfs_file_splice_write( -	struct pipe_inode_info	*pipe, -	struct file		*outfilp, -	loff_t			*ppos, -	size_t			count, -	unsigned int		flags) -{ -	struct inode		*inode = outfilp->f_mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	xfs_fsize_t		new_size; -	int			ioflags = 0; -	ssize_t			ret; - -	XFS_STATS_INC(xs_write_calls); - -	if (outfilp->f_mode & FMODE_NOCMTIME) -		ioflags |= IO_INVIS; - -	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) -		return -EIO; - -	xfs_ilock(ip, XFS_IOLOCK_EXCL); - -	new_size = *ppos + count; - -	xfs_ilock(ip, XFS_ILOCK_EXCL); -	if (new_size > ip->i_size) -		ip->i_new_size = new_size; -	xfs_iunlock(ip, XFS_ILOCK_EXCL); - -	trace_xfs_file_splice_write(ip, count, *ppos, ioflags); - -	ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags); - -	xfs_aio_write_isize_update(inode, ppos, ret); -	xfs_aio_write_newsize_update(ip); -	xfs_iunlock(ip, XFS_IOLOCK_EXCL); -	return ret; -} - -/* - * This routine is called to handle zeroing any space in the last - * block of the file that is beyond the EOF.  We do this since the - * size is being increased without writing anything to that block - * and we don't want anyone to read the garbage on the disk. - */ -STATIC int				/* error (positive) */ -xfs_zero_last_block( -	xfs_inode_t	*ip, -	xfs_fsize_t	offset, -	xfs_fsize_t	isize) -{ -	xfs_fileoff_t	last_fsb; -	xfs_mount_t	*mp = ip->i_mount; -	int		nimaps; -	int		zero_offset; -	int		zero_len; -	int		error = 0; -	xfs_bmbt_irec_t	imap; - -	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); - -	zero_offset = XFS_B_FSB_OFFSET(mp, isize); -	if (zero_offset == 0) { -		/* -		 * There are no extra bytes in the last block on disk to -		 * zero, so return. -		 */ -		return 0; -	} - -	last_fsb = XFS_B_TO_FSBT(mp, isize); -	nimaps = 1; -	error = xfs_bmapi(NULL, ip, last_fsb, 1, 0, NULL, 0, &imap, -			  &nimaps, NULL); -	if (error) { -		return error; -	} -	ASSERT(nimaps > 0); -	/* -	 * If the block underlying isize is just a hole, then there -	 * is nothing to zero. -	 */ -	if (imap.br_startblock == HOLESTARTBLOCK) { -		return 0; -	} -	/* -	 * Zero the part of the last block beyond the EOF, and write it -	 * out sync.  We need to drop the ilock while we do this so we -	 * don't deadlock when the buffer cache calls back to us. -	 */ -	xfs_iunlock(ip, XFS_ILOCK_EXCL); - -	zero_len = mp->m_sb.sb_blocksize - zero_offset; -	if (isize + zero_len > offset) -		zero_len = offset - isize; -	error = xfs_iozero(ip, isize, zero_len); - -	xfs_ilock(ip, XFS_ILOCK_EXCL); -	ASSERT(error >= 0); -	return error; -} - -/* - * Zero any on disk space between the current EOF and the new, - * larger EOF.  This handles the normal case of zeroing the remainder - * of the last block in the file and the unusual case of zeroing blocks - * out beyond the size of the file.  This second case only happens - * with fixed size extents and when the system crashes before the inode - * size was updated but after blocks were allocated.  If fill is set, - * then any holes in the range are filled and zeroed.  If not, the holes - * are left alone as holes. - */ - -int					/* error (positive) */ -xfs_zero_eof( -	xfs_inode_t	*ip, -	xfs_off_t	offset,		/* starting I/O offset */ -	xfs_fsize_t	isize)		/* current inode size */ -{ -	xfs_mount_t	*mp = ip->i_mount; -	xfs_fileoff_t	start_zero_fsb; -	xfs_fileoff_t	end_zero_fsb; -	xfs_fileoff_t	zero_count_fsb; -	xfs_fileoff_t	last_fsb; -	xfs_fileoff_t	zero_off; -	xfs_fsize_t	zero_len; -	int		nimaps; -	int		error = 0; -	xfs_bmbt_irec_t	imap; - -	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL)); -	ASSERT(offset > isize); - -	/* -	 * First handle zeroing the block on which isize resides. -	 * We only zero a part of that block so it is handled specially. -	 */ -	error = xfs_zero_last_block(ip, offset, isize); -	if (error) { -		ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL)); -		return error; -	} - -	/* -	 * Calculate the range between the new size and the old -	 * where blocks needing to be zeroed may exist.  To get the -	 * block where the last byte in the file currently resides, -	 * we need to subtract one from the size and truncate back -	 * to a block boundary.  We subtract 1 in case the size is -	 * exactly on a block boundary. -	 */ -	last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1; -	start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize); -	end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1); -	ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb); -	if (last_fsb == end_zero_fsb) { -		/* -		 * The size was only incremented on its last block. -		 * We took care of that above, so just return. -		 */ -		return 0; -	} - -	ASSERT(start_zero_fsb <= end_zero_fsb); -	while (start_zero_fsb <= end_zero_fsb) { -		nimaps = 1; -		zero_count_fsb = end_zero_fsb - start_zero_fsb + 1; -		error = xfs_bmapi(NULL, ip, start_zero_fsb, zero_count_fsb, -				  0, NULL, 0, &imap, &nimaps, NULL); -		if (error) { -			ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL)); -			return error; -		} -		ASSERT(nimaps > 0); - -		if (imap.br_state == XFS_EXT_UNWRITTEN || -		    imap.br_startblock == HOLESTARTBLOCK) { -			/* -			 * This loop handles initializing pages that were -			 * partially initialized by the code below this -			 * loop. It basically zeroes the part of the page -			 * that sits on a hole and sets the page as P_HOLE -			 * and calls remapf if it is a mapped file. -			 */ -			start_zero_fsb = imap.br_startoff + imap.br_blockcount; -			ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); -			continue; -		} - -		/* -		 * There are blocks we need to zero. -		 * Drop the inode lock while we're doing the I/O. -		 * We'll still have the iolock to protect us. -		 */ -		xfs_iunlock(ip, XFS_ILOCK_EXCL); - -		zero_off = XFS_FSB_TO_B(mp, start_zero_fsb); -		zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount); - -		if ((zero_off + zero_len) > offset) -			zero_len = offset - zero_off; - -		error = xfs_iozero(ip, zero_off, zero_len); -		if (error) { -			goto out_lock; -		} - -		start_zero_fsb = imap.br_startoff + imap.br_blockcount; -		ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); - -		xfs_ilock(ip, XFS_ILOCK_EXCL); -	} - -	return 0; - -out_lock: -	xfs_ilock(ip, XFS_ILOCK_EXCL); -	ASSERT(error >= 0); -	return error; -} - -/* - * Common pre-write limit and setup checks. - * - * Returns with iolock held according to @iolock. - */ -STATIC ssize_t -xfs_file_aio_write_checks( -	struct file		*file, -	loff_t			*pos, -	size_t			*count, -	int			*iolock) -{ -	struct inode		*inode = file->f_mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	xfs_fsize_t		new_size; -	int			error = 0; - -	error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode)); -	if (error) { -		xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock); -		*iolock = 0; -		return error; -	} - -	new_size = *pos + *count; -	if (new_size > ip->i_size) -		ip->i_new_size = new_size; - -	if (likely(!(file->f_mode & FMODE_NOCMTIME))) -		file_update_time(file); - -	/* -	 * If the offset is beyond the size of the file, we need to zero any -	 * blocks that fall between the existing EOF and the start of this -	 * write. -	 */ -	if (*pos > ip->i_size) -		error = -xfs_zero_eof(ip, *pos, ip->i_size); - -	xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); -	if (error) -		return error; - -	/* -	 * If we're writing the file then make sure to clear the setuid and -	 * setgid bits if the process is not being run by root.  This keeps -	 * people from modifying setuid and setgid binaries. -	 */ -	return file_remove_suid(file); - -} - -/* - * xfs_file_dio_aio_write - handle direct IO writes - * - * Lock the inode appropriately to prepare for and issue a direct IO write. - * By separating it from the buffered write path we remove all the tricky to - * follow locking changes and looping. - * - * If there are cached pages or we're extending the file, we need IOLOCK_EXCL - * until we're sure the bytes at the new EOF have been zeroed and/or the cached - * pages are flushed out. - * - * In most cases the direct IO writes will be done holding IOLOCK_SHARED - * allowing them to be done in parallel with reads and other direct IO writes. - * However, if the IO is not aligned to filesystem blocks, the direct IO layer - * needs to do sub-block zeroing and that requires serialisation against other - * direct IOs to the same block. In this case we need to serialise the - * submission of the unaligned IOs so that we don't get racing block zeroing in - * the dio layer.  To avoid the problem with aio, we also need to wait for - * outstanding IOs to complete so that unwritten extent conversion is completed - * before we try to map the overlapping block. This is currently implemented by - * hitting it with a big hammer (i.e. xfs_ioend_wait()). - * - * Returns with locks held indicated by @iolock and errors indicated by - * negative return values. - */ -STATIC ssize_t -xfs_file_dio_aio_write( -	struct kiocb		*iocb, -	const struct iovec	*iovp, -	unsigned long		nr_segs, -	loff_t			pos, -	size_t			ocount, -	int			*iolock) -{ -	struct file		*file = iocb->ki_filp; -	struct address_space	*mapping = file->f_mapping; -	struct inode		*inode = mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	struct xfs_mount	*mp = ip->i_mount; -	ssize_t			ret = 0; -	size_t			count = ocount; -	int			unaligned_io = 0; -	struct xfs_buftarg	*target = XFS_IS_REALTIME_INODE(ip) ? -					mp->m_rtdev_targp : mp->m_ddev_targp; - -	*iolock = 0; -	if ((pos & target->bt_smask) || (count & target->bt_smask)) -		return -XFS_ERROR(EINVAL); - -	if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask)) -		unaligned_io = 1; - -	if (unaligned_io || mapping->nrpages || pos > ip->i_size) -		*iolock = XFS_IOLOCK_EXCL; -	else -		*iolock = XFS_IOLOCK_SHARED; -	xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); - -	ret = xfs_file_aio_write_checks(file, &pos, &count, iolock); -	if (ret) -		return ret; - -	if (mapping->nrpages) { -		WARN_ON(*iolock != XFS_IOLOCK_EXCL); -		ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1, -							FI_REMAPF_LOCKED); -		if (ret) -			return ret; -	} - -	/* -	 * If we are doing unaligned IO, wait for all other IO to drain, -	 * otherwise demote the lock if we had to flush cached pages -	 */ -	if (unaligned_io) -		xfs_ioend_wait(ip); -	else if (*iolock == XFS_IOLOCK_EXCL) { -		xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); -		*iolock = XFS_IOLOCK_SHARED; -	} - -	trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0); -	ret = generic_file_direct_write(iocb, iovp, -			&nr_segs, pos, &iocb->ki_pos, count, ocount); - -	/* No fallback to buffered IO on errors for XFS. */ -	ASSERT(ret < 0 || ret == count); -	return ret; -} - -STATIC ssize_t -xfs_file_buffered_aio_write( -	struct kiocb		*iocb, -	const struct iovec	*iovp, -	unsigned long		nr_segs, -	loff_t			pos, -	size_t			ocount, -	int			*iolock) -{ -	struct file		*file = iocb->ki_filp; -	struct address_space	*mapping = file->f_mapping; -	struct inode		*inode = mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	ssize_t			ret; -	int			enospc = 0; -	size_t			count = ocount; - -	*iolock = XFS_IOLOCK_EXCL; -	xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); - -	ret = xfs_file_aio_write_checks(file, &pos, &count, iolock); -	if (ret) -		return ret; - -	/* We can write back this queue in page reclaim */ -	current->backing_dev_info = mapping->backing_dev_info; - -write_retry: -	trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0); -	ret = generic_file_buffered_write(iocb, iovp, nr_segs, -			pos, &iocb->ki_pos, count, ret); -	/* -	 * if we just got an ENOSPC, flush the inode now we aren't holding any -	 * page locks and retry *once* -	 */ -	if (ret == -ENOSPC && !enospc) { -		ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE); -		if (ret) -			return ret; -		enospc = 1; -		goto write_retry; -	} -	current->backing_dev_info = NULL; -	return ret; -} - -STATIC ssize_t -xfs_file_aio_write( -	struct kiocb		*iocb, -	const struct iovec	*iovp, -	unsigned long		nr_segs, -	loff_t			pos) -{ -	struct file		*file = iocb->ki_filp; -	struct address_space	*mapping = file->f_mapping; -	struct inode		*inode = mapping->host; -	struct xfs_inode	*ip = XFS_I(inode); -	ssize_t			ret; -	int			iolock; -	size_t			ocount = 0; - -	XFS_STATS_INC(xs_write_calls); - -	BUG_ON(iocb->ki_pos != pos); - -	ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ); -	if (ret) -		return ret; - -	if (ocount == 0) -		return 0; - -	xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE); - -	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) -		return -EIO; - -	if (unlikely(file->f_flags & O_DIRECT)) -		ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, -						ocount, &iolock); -	else -		ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos, -						ocount, &iolock); - -	xfs_aio_write_isize_update(inode, &iocb->ki_pos, ret); - -	if (ret <= 0) -		goto out_unlock; - -	/* Handle various SYNC-type writes */ -	if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { -		loff_t end = pos + ret - 1; - -		xfs_rw_iunlock(ip, iolock); -		ret = -xfs_file_fsync(file, pos, end, -				      (file->f_flags & __O_SYNC) ? 0 : 1); -		xfs_rw_ilock(ip, iolock); -	} - -out_unlock: -	xfs_aio_write_newsize_update(ip); -	xfs_rw_iunlock(ip, iolock); -	return ret; -} - -STATIC long -xfs_file_fallocate( -	struct file	*file, -	int		mode, -	loff_t		offset, -	loff_t		len) -{ -	struct inode	*inode = file->f_path.dentry->d_inode; -	long		error; -	loff_t		new_size = 0; -	xfs_flock64_t	bf; -	xfs_inode_t	*ip = XFS_I(inode); -	int		cmd = XFS_IOC_RESVSP; -	int		attr_flags = XFS_ATTR_NOLOCK; - -	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) -		return -EOPNOTSUPP; - -	bf.l_whence = 0; -	bf.l_start = offset; -	bf.l_len = len; - -	xfs_ilock(ip, XFS_IOLOCK_EXCL); - -	if (mode & FALLOC_FL_PUNCH_HOLE) -		cmd = XFS_IOC_UNRESVSP; - -	/* check the new inode size is valid before allocating */ -	if (!(mode & FALLOC_FL_KEEP_SIZE) && -	    offset + len > i_size_read(inode)) { -		new_size = offset + len; -		error = inode_newsize_ok(inode, new_size); -		if (error) -			goto out_unlock; -	} - -	if (file->f_flags & O_DSYNC) -		attr_flags |= XFS_ATTR_SYNC; - -	error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags); -	if (error) -		goto out_unlock; - -	/* Change file size if needed */ -	if (new_size) { -		struct iattr iattr; - -		iattr.ia_valid = ATTR_SIZE; -		iattr.ia_size = new_size; -		error = -xfs_setattr_size(ip, &iattr, XFS_ATTR_NOLOCK); -	} - -out_unlock: -	xfs_iunlock(ip, XFS_IOLOCK_EXCL); -	return error; -} - - -STATIC int -xfs_file_open( -	struct inode	*inode, -	struct file	*file) -{ -	if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) -		return -EFBIG; -	if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb))) -		return -EIO; -	return 0; -} - -STATIC int -xfs_dir_open( -	struct inode	*inode, -	struct file	*file) -{ -	struct xfs_inode *ip = XFS_I(inode); -	int		mode; -	int		error; - -	error = xfs_file_open(inode, file); -	if (error) -		return error; - -	/* -	 * If there are any blocks, read-ahead block 0 as we're almost -	 * certain to have the next operation be a read there. -	 */ -	mode = xfs_ilock_map_shared(ip); -	if (ip->i_d.di_nextents > 0) -		xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK); -	xfs_iunlock(ip, mode); -	return 0; -} - -STATIC int -xfs_file_release( -	struct inode	*inode, -	struct file	*filp) -{ -	return -xfs_release(XFS_I(inode)); -} - -STATIC int -xfs_file_readdir( -	struct file	*filp, -	void		*dirent, -	filldir_t	filldir) -{ -	struct inode	*inode = filp->f_path.dentry->d_inode; -	xfs_inode_t	*ip = XFS_I(inode); -	int		error; -	size_t		bufsize; - -	/* -	 * The Linux API doesn't pass down the total size of the buffer -	 * we read into down to the filesystem.  With the filldir concept -	 * it's not needed for correct information, but the XFS dir2 leaf -	 * code wants an estimate of the buffer size to calculate it's -	 * readahead window and size the buffers used for mapping to -	 * physical blocks. -	 * -	 * Try to give it an estimate that's good enough, maybe at some -	 * point we can change the ->readdir prototype to include the -	 * buffer size.  For now we use the current glibc buffer size. -	 */ -	bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size); - -	error = xfs_readdir(ip, dirent, bufsize, -				(xfs_off_t *)&filp->f_pos, filldir); -	if (error) -		return -error; -	return 0; -} - -STATIC int -xfs_file_mmap( -	struct file	*filp, -	struct vm_area_struct *vma) -{ -	vma->vm_ops = &xfs_file_vm_ops; -	vma->vm_flags |= VM_CAN_NONLINEAR; - -	file_accessed(filp); -	return 0; -} - -/* - * mmap()d file has taken write protection fault and is being made - * writable. We can set the page state up correctly for a writable - * page, which means we can do correct delalloc accounting (ENOSPC - * checking!) and unwritten extent mapping. - */ -STATIC int -xfs_vm_page_mkwrite( -	struct vm_area_struct	*vma, -	struct vm_fault		*vmf) -{ -	return block_page_mkwrite(vma, vmf, xfs_get_blocks); -} - -const struct file_operations xfs_file_operations = { -	.llseek		= generic_file_llseek, -	.read		= do_sync_read, -	.write		= do_sync_write, -	.aio_read	= xfs_file_aio_read, -	.aio_write	= xfs_file_aio_write, -	.splice_read	= xfs_file_splice_read, -	.splice_write	= xfs_file_splice_write, -	.unlocked_ioctl	= xfs_file_ioctl, -#ifdef CONFIG_COMPAT -	.compat_ioctl	= xfs_file_compat_ioctl, -#endif -	.mmap		= xfs_file_mmap, -	.open		= xfs_file_open, -	.release	= xfs_file_release, -	.fsync		= xfs_file_fsync, -	.fallocate	= xfs_file_fallocate, -}; - -const struct file_operations xfs_dir_file_operations = { -	.open		= xfs_dir_open, -	.read		= generic_read_dir, -	.readdir	= xfs_file_readdir, -	.llseek		= generic_file_llseek, -	.unlocked_ioctl	= xfs_file_ioctl, -#ifdef CONFIG_COMPAT -	.compat_ioctl	= xfs_file_compat_ioctl, -#endif -	.fsync		= xfs_file_fsync, -}; - -static const struct vm_operations_struct xfs_file_vm_ops = { -	.fault		= filemap_fault, -	.page_mkwrite	= xfs_vm_page_mkwrite, -}; |