| /* |
| * 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; |
| xfs_lsn_t lsn = 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); |
| |
| 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); |
| error = xfs_trans_commit(tp, 0); |
| |
| lsn = ip->i_itemp->ili_last_lsn; |
| 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)) |
| lsn = ip->i_itemp->ili_last_lsn; |
| xfs_iunlock(ip, XFS_ILOCK_SHARED); |
| } |
| |
| if (!error && lsn) |
| error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed); |
| |
| /* |
| * 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; |
| |
| /* |
| * Locking is a bit tricky here. If we take an exclusive lock |
| * for direct IO, we effectively serialise all new concurrent |
| * read IO to this file and block it behind IO that is currently in |
| * progress because IO in progress holds the IO lock shared. We only |
| * need to hold the lock exclusive to blow away the page cache, so |
| * only take lock exclusively if the page cache needs invalidation. |
| * This allows the normal direct IO case of no page cache pages to |
| * proceeed concurrently without serialisation. |
| */ |
| xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); |
| if ((ioflags & IO_ISDIRECT) && inode->i_mapping->nrpages) { |
| xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); |
| 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); |
| } |
| |
| 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, |
| xfs_fsize_t new_size) |
| { |
| if (new_size == ip->i_new_size) { |
| xfs_rw_ilock(ip, XFS_ILOCK_EXCL); |
| if (new_size == ip->i_new_size) |
| 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, new_size); |
| 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_read(ip, last_fsb, 1, &imap, &nimaps, 0); |
| 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_read(ip, start_zero_fsb, zero_count_fsb, |
| &imap, &nimaps, 0); |
| 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, |
| xfs_fsize_t *new_sizep, |
| int *iolock) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct xfs_inode *ip = XFS_I(inode); |
| xfs_fsize_t new_size; |
| int error = 0; |
| |
| xfs_rw_ilock(ip, XFS_ILOCK_EXCL); |
| *new_sizep = 0; |
| restart: |
| 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; |
| } |
| |
| 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. There is no need to issue zeroing if another in-flght IO ends |
| * at or before this one If zeronig is needed and we are currently |
| * holding the iolock shared, we need to update it to exclusive which |
| * involves dropping all locks and relocking to maintain correct locking |
| * order. If we do this, restart the function to ensure all checks and |
| * values are still valid. |
| */ |
| if ((ip->i_new_size && *pos > ip->i_new_size) || |
| (!ip->i_new_size && *pos > ip->i_size)) { |
| if (*iolock == XFS_IOLOCK_SHARED) { |
| xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock); |
| *iolock = XFS_IOLOCK_EXCL; |
| xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); |
| goto restart; |
| } |
| error = -xfs_zero_eof(ip, *pos, ip->i_size); |
| } |
| |
| /* |
| * If this IO extends beyond EOF, we may need to update ip->i_new_size. |
| * We have already zeroed space beyond EOF (if necessary). Only update |
| * ip->i_new_size if this IO ends beyond any other in-flight writes. |
| */ |
| new_size = *pos + *count; |
| if (new_size > ip->i_size) { |
| if (new_size > ip->i_new_size) |
| ip->i_new_size = new_size; |
| *new_sizep = new_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. inode_dio_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, |
| xfs_fsize_t *new_size, |
| 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; |
| |
| /* |
| * We don't need to take an exclusive lock unless there page cache needs |
| * to be invalidated or unaligned IO is being executed. We don't need to |
| * consider the EOF extension case here because |
| * xfs_file_aio_write_checks() will relock the inode as necessary for |
| * EOF zeroing cases and fill out the new inode size as appropriate. |
| */ |
| if (unaligned_io || mapping->nrpages) |
| *iolock = XFS_IOLOCK_EXCL; |
| else |
| *iolock = XFS_IOLOCK_SHARED; |
| xfs_rw_ilock(ip, *iolock); |
| |
| /* |
| * Recheck if there are cached pages that need invalidate after we got |
| * the iolock to protect against other threads adding new pages while |
| * we were waiting for the iolock. |
| */ |
| if (mapping->nrpages && *iolock == XFS_IOLOCK_SHARED) { |
| xfs_rw_iunlock(ip, *iolock); |
| *iolock = XFS_IOLOCK_EXCL; |
| xfs_rw_ilock(ip, *iolock); |
| } |
| |
| ret = xfs_file_aio_write_checks(file, &pos, &count, new_size, iolock); |
| if (ret) |
| return ret; |
| |
| if (mapping->nrpages) { |
| 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) |
| inode_dio_wait(inode); |
| 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, |
| xfs_fsize_t *new_size, |
| 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, *iolock); |
| |
| ret = xfs_file_aio_write_checks(file, &pos, &count, new_size, 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_fsize_t new_size = 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, &new_size, &iolock); |
| else |
| ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos, |
| ocount, &new_size, &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; |
| int error; |
| |
| xfs_rw_iunlock(ip, iolock); |
| error = xfs_file_fsync(file, pos, end, |
| (file->f_flags & __O_SYNC) ? 0 : 1); |
| xfs_rw_ilock(ip, iolock); |
| if (error) |
| ret = error; |
| } |
| |
| out_unlock: |
| xfs_aio_write_newsize_update(ip, new_size); |
| 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, |
| }; |