// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_inode.h" #include "xfs_trans.h" #include "xfs_inode_item.h" #include "xfs_bmap.h" #include "xfs_bmap_util.h" #include "xfs_dir2.h" #include "xfs_dir2_priv.h" #include "xfs_ioctl.h" #include "xfs_trace.h" #include "xfs_log.h" #include "xfs_icache.h" #include "xfs_pnfs.h" #include "xfs_iomap.h" #include "xfs_reflink.h" #include #include #include #include static const struct vm_operations_struct xfs_file_vm_ops; /* * Decide if the given file range is aligned to the size of the fundamental * allocation unit for the file. */ static bool xfs_is_falloc_aligned( struct xfs_inode *ip, loff_t pos, long long int len) { struct xfs_mount *mp = ip->i_mount; uint64_t mask; if (XFS_IS_REALTIME_INODE(ip)) { if (!is_power_of_2(mp->m_sb.sb_rextsize)) { u64 rextbytes; u32 mod; rextbytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize); div_u64_rem(pos, rextbytes, &mod); if (mod) return false; div_u64_rem(len, rextbytes, &mod); return mod == 0; } mask = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize) - 1; } else { mask = mp->m_sb.sb_blocksize - 1; } return !((pos | len) & mask); } int xfs_update_prealloc_flags( struct xfs_inode *ip, enum xfs_prealloc_flags flags) { struct xfs_trans *tp; int error; error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid, 0, 0, 0, &tp); if (error) return error; xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); if (!(flags & XFS_PREALLOC_INVISIBLE)) { VFS_I(ip)->i_mode &= ~S_ISUID; if (VFS_I(ip)->i_mode & S_IXGRP) VFS_I(ip)->i_mode &= ~S_ISGID; xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); } if (flags & XFS_PREALLOC_SET) ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC; if (flags & XFS_PREALLOC_CLEAR) ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC; xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); if (flags & XFS_PREALLOC_SYNC) xfs_trans_set_sync(tp); return xfs_trans_commit(tp); } /* * Fsync operations on directories are much simpler than on regular files, * as there is no file data to flush, and thus also no need for explicit * cache flush operations, and there are no non-transaction metadata updates * on directories either. */ STATIC int xfs_dir_fsync( struct file *file, loff_t start, loff_t end, int datasync) { struct xfs_inode *ip = XFS_I(file->f_mapping->host); trace_xfs_dir_fsync(ip); return xfs_log_force_inode(ip); } static xfs_csn_t xfs_fsync_seq( struct xfs_inode *ip, bool datasync) { if (!xfs_ipincount(ip)) return 0; if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) return 0; return ip->i_itemp->ili_commit_seq; } /* * All metadata updates are logged, which means that we just have to flush the * log up to the latest LSN that touched the inode. * * If we have concurrent fsync/fdatasync() calls, we need them to all block on * the log force before we clear the ili_fsync_fields field. This ensures that * we don't get a racing sync operation that does not wait for the metadata to * hit the journal before returning. If we race with clearing ili_fsync_fields, * then all that will happen is the log force will do nothing as the lsn will * already be on disk. We can't race with setting ili_fsync_fields because that * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock * shared until after the ili_fsync_fields is cleared. */ static int xfs_fsync_flush_log( struct xfs_inode *ip, bool datasync, int *log_flushed) { int error = 0; xfs_csn_t seq; xfs_ilock(ip, XFS_ILOCK_SHARED); seq = xfs_fsync_seq(ip, datasync); if (seq) { error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC, log_flushed); spin_lock(&ip->i_itemp->ili_lock); ip->i_itemp->ili_fsync_fields = 0; spin_unlock(&ip->i_itemp->ili_lock); } xfs_iunlock(ip, XFS_ILOCK_SHARED); return error; } STATIC int xfs_file_fsync( struct file *file, loff_t start, loff_t end, int datasync) { struct xfs_inode *ip = XFS_I(file->f_mapping->host); struct xfs_mount *mp = ip->i_mount; int error = 0; int log_flushed = 0; trace_xfs_file_fsync(ip); error = file_write_and_wait_range(file, start, end); if (error) return error; if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; xfs_iflags_clear(ip, XFS_ITRUNCATED); /* * 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); error = xfs_fsync_flush_log(ip, datasync, &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 (!log_flushed && !XFS_IS_REALTIME_INODE(ip) && mp->m_logdev_targp == mp->m_ddev_targp) xfs_blkdev_issue_flush(mp->m_ddev_targp); return error; } STATIC ssize_t xfs_file_dio_aio_read( struct kiocb *iocb, struct iov_iter *to) { struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); size_t count = iov_iter_count(to); ssize_t ret; trace_xfs_file_direct_read(ip, count, iocb->ki_pos); if (!count) return 0; /* skip atime */ file_accessed(iocb->ki_filp); if (iocb->ki_flags & IOCB_NOWAIT) { if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) return -EAGAIN; } else { xfs_ilock(ip, XFS_IOLOCK_SHARED); } ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, is_sync_kiocb(iocb)); xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } static noinline ssize_t xfs_file_dax_read( struct kiocb *iocb, struct iov_iter *to) { struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host); size_t count = iov_iter_count(to); ssize_t ret = 0; trace_xfs_file_dax_read(ip, count, iocb->ki_pos); if (!count) return 0; /* skip atime */ if (iocb->ki_flags & IOCB_NOWAIT) { if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) return -EAGAIN; } else { xfs_ilock(ip, XFS_IOLOCK_SHARED); } ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops); xfs_iunlock(ip, XFS_IOLOCK_SHARED); file_accessed(iocb->ki_filp); return ret; } STATIC ssize_t xfs_file_buffered_aio_read( struct kiocb *iocb, struct iov_iter *to) { struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); ssize_t ret; trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos); if (iocb->ki_flags & IOCB_NOWAIT) { if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) return -EAGAIN; } else { xfs_ilock(ip, XFS_IOLOCK_SHARED); } ret = generic_file_read_iter(iocb, to); xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } STATIC ssize_t xfs_file_read_iter( struct kiocb *iocb, struct iov_iter *to) { struct inode *inode = file_inode(iocb->ki_filp); struct xfs_mount *mp = XFS_I(inode)->i_mount; ssize_t ret = 0; XFS_STATS_INC(mp, xs_read_calls); if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; if (IS_DAX(inode)) ret = xfs_file_dax_read(iocb, to); else if (iocb->ki_flags & IOCB_DIRECT) ret = xfs_file_dio_aio_read(iocb, to); else ret = xfs_file_buffered_aio_read(iocb, to); if (ret > 0) XFS_STATS_ADD(mp, xs_read_bytes, ret); return ret; } /* * Common pre-write limit and setup checks. * * Called with the iolocked held either shared and exclusive according to * @iolock, and returns with it held. Might upgrade the iolock to exclusive * if called for a direct write beyond i_size. */ STATIC ssize_t xfs_file_aio_write_checks( struct kiocb *iocb, struct iov_iter *from, int *iolock) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; struct xfs_inode *ip = XFS_I(inode); ssize_t error = 0; size_t count = iov_iter_count(from); bool drained_dio = false; loff_t isize; restart: error = generic_write_checks(iocb, from); if (error <= 0) return error; error = xfs_break_layouts(inode, iolock, BREAK_WRITE); if (error) return error; /* * For changing security info in file_remove_privs() we need i_rwsem * exclusively. */ if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) { xfs_iunlock(ip, *iolock); *iolock = XFS_IOLOCK_EXCL; xfs_ilock(ip, *iolock); goto restart; } /* * 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 zeroing is needed and we are currently holding the * iolock shared, we need to update it to exclusive which implies * having to redo all checks before. * * We need to serialise against EOF updates that occur in IO * completions here. We want to make sure that nobody is changing the * size while we do this check until we have placed an IO barrier (i.e. * hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. * The spinlock effectively forms a memory barrier once we have the * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value * and hence be able to correctly determine if we need to run zeroing. */ spin_lock(&ip->i_flags_lock); isize = i_size_read(inode); if (iocb->ki_pos > isize) { spin_unlock(&ip->i_flags_lock); if (!drained_dio) { if (*iolock == XFS_IOLOCK_SHARED) { xfs_iunlock(ip, *iolock); *iolock = XFS_IOLOCK_EXCL; xfs_ilock(ip, *iolock); iov_iter_reexpand(from, count); } /* * We now have an IO submission barrier in place, but * AIO can do EOF updates during IO completion and hence * we now need to wait for all of them to drain. Non-AIO * DIO will have drained before we are given the * XFS_IOLOCK_EXCL, and so for most cases this wait is a * no-op. */ inode_dio_wait(inode); drained_dio = true; goto restart; } trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize); error = iomap_zero_range(inode, isize, iocb->ki_pos - isize, NULL, &xfs_buffered_write_iomap_ops); if (error) return error; } else spin_unlock(&ip->i_flags_lock); /* * Updating the timestamps will grab the ilock again from * xfs_fs_dirty_inode, so we have to call it after dropping the * lock above. Eventually we should look into a way to avoid * the pointless lock roundtrip. */ return file_modified(file); } static int xfs_dio_write_end_io( struct kiocb *iocb, ssize_t size, int error, unsigned flags) { struct inode *inode = file_inode(iocb->ki_filp); struct xfs_inode *ip = XFS_I(inode); loff_t offset = iocb->ki_pos; unsigned int nofs_flag; trace_xfs_end_io_direct_write(ip, offset, size); if (XFS_FORCED_SHUTDOWN(ip->i_mount)) return -EIO; if (error) return error; if (!size) return 0; /* * Capture amount written on completion as we can't reliably account * for it on submission. */ XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size); /* * We can allocate memory here while doing writeback on behalf of * memory reclaim. To avoid memory allocation deadlocks set the * task-wide nofs context for the following operations. */ nofs_flag = memalloc_nofs_save(); if (flags & IOMAP_DIO_COW) { error = xfs_reflink_end_cow(ip, offset, size); if (error) goto out; } /* * Unwritten conversion updates the in-core isize after extent * conversion but before updating the on-disk size. Updating isize any * earlier allows a racing dio read to find unwritten extents before * they are converted. */ if (flags & IOMAP_DIO_UNWRITTEN) { error = xfs_iomap_write_unwritten(ip, offset, size, true); goto out; } /* * We need to update the in-core inode size here so that we don't end up * with the on-disk inode size being outside the in-core inode size. We * have no other method of updating EOF for AIO, so always do it here * if necessary. * * We need to lock the test/set EOF update as we can be racing with * other IO completions here to update the EOF. Failing to serialise * here can result in EOF moving backwards and Bad Things Happen when * that occurs. */ spin_lock(&ip->i_flags_lock); if (offset + size > i_size_read(inode)) { i_size_write(inode, offset + size); spin_unlock(&ip->i_flags_lock); error = xfs_setfilesize(ip, offset, size); } else { spin_unlock(&ip->i_flags_lock); } out: memalloc_nofs_restore(nofs_flag); return error; } static const struct iomap_dio_ops xfs_dio_write_ops = { .end_io = xfs_dio_write_end_io, }; /* * 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, struct iov_iter *from) { 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; int unaligned_io = 0; int iolock; size_t count = iov_iter_count(from); struct xfs_buftarg *target = xfs_inode_buftarg(ip); /* DIO must be aligned to device logical sector size */ if ((iocb->ki_pos | count) & target->bt_logical_sectormask) return -EINVAL; /* * Don't take the exclusive iolock here unless the I/O is unaligned to * the file system block size. 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 ((iocb->ki_pos & mp->m_blockmask) || ((iocb->ki_pos + count) & mp->m_blockmask)) { unaligned_io = 1; /* * We can't properly handle unaligned direct I/O to reflink * files yet, as we can't unshare a partial block. */ if (xfs_is_cow_inode(ip)) { trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count); return -ENOTBLK; } iolock = XFS_IOLOCK_EXCL; } else { iolock = XFS_IOLOCK_SHARED; } if (iocb->ki_flags & IOCB_NOWAIT) { /* unaligned dio always waits, bail */ if (unaligned_io) return -EAGAIN; if (!xfs_ilock_nowait(ip, iolock)) return -EAGAIN; } else { xfs_ilock(ip, iolock); } ret = xfs_file_aio_write_checks(iocb, from, &iolock); if (ret) goto out; count = iov_iter_count(from); /* * If we are doing unaligned IO, we can't allow any other overlapping IO * in-flight at the same time or we risk data corruption. Wait for all * other IO to drain before we submit. If the IO is aligned, demote the * iolock if we had to take the exclusive lock in * xfs_file_aio_write_checks() for other reasons. */ if (unaligned_io) { inode_dio_wait(inode); } else if (iolock == XFS_IOLOCK_EXCL) { xfs_ilock_demote(ip, XFS_IOLOCK_EXCL); iolock = XFS_IOLOCK_SHARED; } trace_xfs_file_direct_write(ip, count, iocb->ki_pos); /* * If unaligned, this is the only IO in-flight. Wait on it before we * release the iolock to prevent subsequent overlapping IO. */ ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops, &xfs_dio_write_ops, is_sync_kiocb(iocb) || unaligned_io); out: xfs_iunlock(ip, iolock); /* * No fallback to buffered IO after short writes for XFS, direct I/O * will either complete fully or return an error. */ ASSERT(ret < 0 || ret == count); return ret; } static noinline ssize_t xfs_file_dax_write( struct kiocb *iocb, struct iov_iter *from) { struct inode *inode = iocb->ki_filp->f_mapping->host; struct xfs_inode *ip = XFS_I(inode); int iolock = XFS_IOLOCK_EXCL; ssize_t ret, error = 0; size_t count; loff_t pos; if (iocb->ki_flags & IOCB_NOWAIT) { if (!xfs_ilock_nowait(ip, iolock)) return -EAGAIN; } else { xfs_ilock(ip, iolock); } ret = xfs_file_aio_write_checks(iocb, from, &iolock); if (ret) goto out; pos = iocb->ki_pos; count = iov_iter_count(from); trace_xfs_file_dax_write(ip, count, pos); ret = dax_iomap_rw(iocb, from, &xfs_direct_write_iomap_ops); if (ret > 0 && iocb->ki_pos > i_size_read(inode)) { i_size_write(inode, iocb->ki_pos); error = xfs_setfilesize(ip, pos, ret); } out: xfs_iunlock(ip, iolock); if (error) return error; if (ret > 0) { XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret); /* Handle various SYNC-type writes */ ret = generic_write_sync(iocb, ret); } return ret; } STATIC ssize_t xfs_file_buffered_aio_write( struct kiocb *iocb, struct iov_iter *from) { 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; int iolock; if (iocb->ki_flags & IOCB_NOWAIT) return -EOPNOTSUPP; write_retry: iolock = XFS_IOLOCK_EXCL; xfs_ilock(ip, iolock); ret = xfs_file_aio_write_checks(iocb, from, &iolock); if (ret) goto out; /* We can write back this queue in page reclaim */ current->backing_dev_info = inode_to_bdi(inode); trace_xfs_file_buffered_write(ip, iov_iter_count(from), iocb->ki_pos); ret = iomap_file_buffered_write(iocb, from, &xfs_buffered_write_iomap_ops); if (likely(ret >= 0)) iocb->ki_pos += ret; /* * If we hit a space limit, try to free up some lingering preallocated * space before returning an error. In the case of ENOSPC, first try to * write back all dirty inodes to free up some of the excess reserved * metadata space. This reduces the chances that the eofblocks scan * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this * also behaves as a filter to prevent too many eofblocks scans from * running at the same time. */ if (ret == -EDQUOT && !enospc) { xfs_iunlock(ip, iolock); enospc = xfs_inode_free_quota_eofblocks(ip); if (enospc) goto write_retry; enospc = xfs_inode_free_quota_cowblocks(ip); if (enospc) goto write_retry; iolock = 0; } else if (ret == -ENOSPC && !enospc) { struct xfs_eofblocks eofb = {0}; enospc = 1; xfs_flush_inodes(ip->i_mount); xfs_iunlock(ip, iolock); eofb.eof_flags = XFS_EOF_FLAGS_SYNC; xfs_icache_free_eofblocks(ip->i_mount, &eofb); xfs_icache_free_cowblocks(ip->i_mount, &eofb); goto write_retry; } current->backing_dev_info = NULL; out: if (iolock) xfs_iunlock(ip, iolock); if (ret > 0) { XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret); /* Handle various SYNC-type writes */ ret = generic_write_sync(iocb, ret); } return ret; } STATIC ssize_t xfs_file_write_iter( struct kiocb *iocb, struct iov_iter *from) { 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; size_t ocount = iov_iter_count(from); XFS_STATS_INC(ip->i_mount, xs_write_calls); if (ocount == 0) return 0; if (XFS_FORCED_SHUTDOWN(ip->i_mount)) return -EIO; if (IS_DAX(inode)) return xfs_file_dax_write(iocb, from); if (iocb->ki_flags & IOCB_DIRECT) { /* * Allow a directio write to fall back to a buffered * write *only* in the case that we're doing a reflink * CoW. In all other directio scenarios we do not * allow an operation to fall back to buffered mode. */ ret = xfs_file_dio_aio_write(iocb, from); if (ret != -ENOTBLK) return ret; } return xfs_file_buffered_aio_write(iocb, from); } static void xfs_wait_dax_page( struct inode *inode) { struct xfs_inode *ip = XFS_I(inode); xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); schedule(); xfs_ilock(ip, XFS_MMAPLOCK_EXCL); } static int xfs_break_dax_layouts( struct inode *inode, bool *retry) { struct page *page; ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL)); page = dax_layout_busy_page(inode->i_mapping); if (!page) return 0; *retry = true; return ___wait_var_event(&page->_refcount, atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, 0, 0, xfs_wait_dax_page(inode)); } int xfs_break_layouts( struct inode *inode, uint *iolock, enum layout_break_reason reason) { bool retry; int error; ASSERT(xfs_isilocked(XFS_I(inode), XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)); do { retry = false; switch (reason) { case BREAK_UNMAP: error = xfs_break_dax_layouts(inode, &retry); if (error || retry) break; /* fall through */ case BREAK_WRITE: error = xfs_break_leased_layouts(inode, iolock, &retry); break; default: WARN_ON_ONCE(1); error = -EINVAL; } } while (error == 0 && retry); return error; } #define XFS_FALLOC_FL_SUPPORTED \ (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \ FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE) STATIC long xfs_file_fallocate( struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct xfs_inode *ip = XFS_I(inode); long error; enum xfs_prealloc_flags flags = 0; uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL; loff_t new_size = 0; bool do_file_insert = false; if (!S_ISREG(inode->i_mode)) return -EINVAL; if (mode & ~XFS_FALLOC_FL_SUPPORTED) return -EOPNOTSUPP; xfs_ilock(ip, iolock); error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP); if (error) goto out_unlock; /* * Must wait for all AIO to complete before we continue as AIO can * change the file size on completion without holding any locks we * currently hold. We must do this first because AIO can update both * the on disk and in memory inode sizes, and the operations that follow * require the in-memory size to be fully up-to-date. */ inode_dio_wait(inode); /* * Now AIO and DIO has drained we flush and (if necessary) invalidate * the cached range over the first operation we are about to run. * * We care about zero and collapse here because they both run a hole * punch over the range first. Because that can zero data, and the range * of invalidation for the shift operations is much larger, we still do * the required flush for collapse in xfs_prepare_shift(). * * Insert has the same range requirements as collapse, and we extend the * file first which can zero data. Hence insert has the same * flush/invalidate requirements as collapse and so they are both * handled at the right time by xfs_prepare_shift(). */ if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE | FALLOC_FL_COLLAPSE_RANGE)) { error = xfs_flush_unmap_range(ip, offset, len); if (error) goto out_unlock; } if (mode & FALLOC_FL_PUNCH_HOLE) { error = xfs_free_file_space(ip, offset, len); if (error) goto out_unlock; } else if (mode & FALLOC_FL_COLLAPSE_RANGE) { if (!xfs_is_falloc_aligned(ip, offset, len)) { error = -EINVAL; goto out_unlock; } /* * There is no need to overlap collapse range with EOF, * in which case it is effectively a truncate operation */ if (offset + len >= i_size_read(inode)) { error = -EINVAL; goto out_unlock; } new_size = i_size_read(inode) - len; error = xfs_collapse_file_space(ip, offset, len); if (error) goto out_unlock; } else if (mode & FALLOC_FL_INSERT_RANGE) { loff_t isize = i_size_read(inode); if (!xfs_is_falloc_aligned(ip, offset, len)) { error = -EINVAL; goto out_unlock; } /* * New inode size must not exceed ->s_maxbytes, accounting for * possible signed overflow. */ if (inode->i_sb->s_maxbytes - isize < len) { error = -EFBIG; goto out_unlock; } new_size = isize + len; /* Offset should be less than i_size */ if (offset >= isize) { error = -EINVAL; goto out_unlock; } do_file_insert = true; } else { flags |= XFS_PREALLOC_SET; 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 (mode & FALLOC_FL_ZERO_RANGE) { /* * Punch a hole and prealloc the range. We use a hole * punch rather than unwritten extent conversion for two * reasons: * * 1.) Hole punch handles partial block zeroing for us. * 2.) If prealloc returns ENOSPC, the file range is * still zero-valued by virtue of the hole punch. */ unsigned int blksize = i_blocksize(inode); trace_xfs_zero_file_space(ip); error = xfs_free_file_space(ip, offset, len); if (error) goto out_unlock; len = round_up(offset + len, blksize) - round_down(offset, blksize); offset = round_down(offset, blksize); } else if (mode & FALLOC_FL_UNSHARE_RANGE) { error = xfs_reflink_unshare(ip, offset, len); if (error) goto out_unlock; } else { /* * If always_cow mode we can't use preallocations and * thus should not create them. */ if (xfs_is_always_cow_inode(ip)) { error = -EOPNOTSUPP; goto out_unlock; } } if (!xfs_is_always_cow_inode(ip)) { error = xfs_alloc_file_space(ip, offset, len, XFS_BMAPI_PREALLOC); if (error) goto out_unlock; } } if (file->f_flags & O_DSYNC) flags |= XFS_PREALLOC_SYNC; error = xfs_update_prealloc_flags(ip, 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_vn_setattr_size(file_dentry(file), &iattr); if (error) goto out_unlock; } /* * Perform hole insertion now that the file size has been * updated so that if we crash during the operation we don't * leave shifted extents past EOF and hence losing access to * the data that is contained within them. */ if (do_file_insert) error = xfs_insert_file_space(ip, offset, len); out_unlock: xfs_iunlock(ip, iolock); return error; } STATIC int xfs_file_fadvise( struct file *file, loff_t start, loff_t end, int advice) { struct xfs_inode *ip = XFS_I(file_inode(file)); int ret; int lockflags = 0; /* * Operations creating pages in page cache need protection from hole * punching and similar ops */ if (advice == POSIX_FADV_WILLNEED) { lockflags = XFS_IOLOCK_SHARED; xfs_ilock(ip, lockflags); } ret = generic_fadvise(file, start, end, advice); if (lockflags) xfs_iunlock(ip, lockflags); return ret; } /* Does this file, inode, or mount want synchronous writes? */ static inline bool xfs_file_sync_writes(struct file *filp) { struct xfs_inode *ip = XFS_I(file_inode(filp)); if (ip->i_mount->m_flags & XFS_MOUNT_WSYNC) return true; if (filp->f_flags & (__O_SYNC | O_DSYNC)) return true; if (IS_SYNC(file_inode(filp))) return true; return false; } STATIC loff_t xfs_file_remap_range( struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t len, unsigned int remap_flags) { struct inode *inode_in = file_inode(file_in); struct xfs_inode *src = XFS_I(inode_in); struct inode *inode_out = file_inode(file_out); struct xfs_inode *dest = XFS_I(inode_out); struct xfs_mount *mp = src->i_mount; loff_t remapped = 0; xfs_extlen_t cowextsize; int ret; if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) return -EINVAL; if (!xfs_sb_version_hasreflink(&mp->m_sb)) return -EOPNOTSUPP; if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; /* Prepare and then clone file data. */ ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out, &len, remap_flags); if (ret || len == 0) return ret; trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len, &remapped); if (ret) goto out_unlock; /* * Carry the cowextsize hint from src to dest if we're sharing the * entire source file to the entire destination file, the source file * has a cowextsize hint, and the destination file does not. */ cowextsize = 0; if (pos_in == 0 && len == i_size_read(inode_in) && (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && pos_out == 0 && len >= i_size_read(inode_out) && !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) cowextsize = src->i_d.di_cowextsize; ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize, remap_flags); if (ret) goto out_unlock; if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out)) xfs_log_force_inode(dest); out_unlock: xfs_iunlock2_io_mmap(src, dest); if (ret) trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); return remapped > 0 ? remapped : ret; } 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; file->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; 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_data_map_shared(ip); if (ip->i_df.if_nextents > 0) error = xfs_dir3_data_readahead(ip, 0, 0); xfs_iunlock(ip, mode); return error; } STATIC int xfs_file_release( struct inode *inode, struct file *filp) { return xfs_release(XFS_I(inode)); } STATIC int xfs_file_readdir( struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); xfs_inode_t *ip = XFS_I(inode); 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, XFS_READDIR_BUFSIZE, ip->i_d.di_size); return xfs_readdir(NULL, ip, ctx, bufsize); } STATIC loff_t xfs_file_llseek( struct file *file, loff_t offset, int whence) { struct inode *inode = file->f_mapping->host; if (XFS_FORCED_SHUTDOWN(XFS_I(inode)->i_mount)) return -EIO; switch (whence) { default: return generic_file_llseek(file, offset, whence); case SEEK_HOLE: offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops); break; case SEEK_DATA: offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops); break; } if (offset < 0) return offset; return vfs_setpos(file, offset, inode->i_sb->s_maxbytes); } /* * Locking for serialisation of IO during page faults. This results in a lock * ordering of: * * mmap_lock (MM) * sb_start_pagefault(vfs, freeze) * i_mmaplock (XFS - truncate serialisation) * page_lock (MM) * i_lock (XFS - extent map serialisation) */ static vm_fault_t __xfs_filemap_fault( struct vm_fault *vmf, enum page_entry_size pe_size, bool write_fault) { struct inode *inode = file_inode(vmf->vma->vm_file); struct xfs_inode *ip = XFS_I(inode); vm_fault_t ret; trace_xfs_filemap_fault(ip, pe_size, write_fault); if (write_fault) { sb_start_pagefault(inode->i_sb); file_update_time(vmf->vma->vm_file); } xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (IS_DAX(inode)) { pfn_t pfn; ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, (write_fault && !vmf->cow_page) ? &xfs_direct_write_iomap_ops : &xfs_read_iomap_ops); if (ret & VM_FAULT_NEEDDSYNC) ret = dax_finish_sync_fault(vmf, pe_size, pfn); } else { if (write_fault) ret = iomap_page_mkwrite(vmf, &xfs_buffered_write_iomap_ops); else ret = filemap_fault(vmf); } xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (write_fault) sb_end_pagefault(inode->i_sb); return ret; } static inline bool xfs_is_write_fault( struct vm_fault *vmf) { return (vmf->flags & FAULT_FLAG_WRITE) && (vmf->vma->vm_flags & VM_SHARED); } static vm_fault_t xfs_filemap_fault( struct vm_fault *vmf) { /* DAX can shortcut the normal fault path on write faults! */ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, IS_DAX(file_inode(vmf->vma->vm_file)) && xfs_is_write_fault(vmf)); } static vm_fault_t xfs_filemap_huge_fault( struct vm_fault *vmf, enum page_entry_size pe_size) { if (!IS_DAX(file_inode(vmf->vma->vm_file))) return VM_FAULT_FALLBACK; /* DAX can shortcut the normal fault path on write faults! */ return __xfs_filemap_fault(vmf, pe_size, xfs_is_write_fault(vmf)); } static vm_fault_t xfs_filemap_page_mkwrite( struct vm_fault *vmf) { return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true); } /* * pfn_mkwrite was originally intended to ensure we capture time stamp updates * on write faults. In reality, it needs to serialise against truncate and * prepare memory for writing so handle is as standard write fault. */ static vm_fault_t xfs_filemap_pfn_mkwrite( struct vm_fault *vmf) { return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true); } static void xfs_filemap_map_pages( struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff) { struct inode *inode = file_inode(vmf->vma->vm_file); xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); filemap_map_pages(vmf, start_pgoff, end_pgoff); xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); } static const struct vm_operations_struct xfs_file_vm_ops = { .fault = xfs_filemap_fault, .huge_fault = xfs_filemap_huge_fault, .map_pages = xfs_filemap_map_pages, .page_mkwrite = xfs_filemap_page_mkwrite, .pfn_mkwrite = xfs_filemap_pfn_mkwrite, }; STATIC int xfs_file_mmap( struct file *file, struct vm_area_struct *vma) { struct inode *inode = file_inode(file); struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode)); /* * We don't support synchronous mappings for non-DAX files and * for DAX files if underneath dax_device is not synchronous. */ if (!daxdev_mapping_supported(vma, target->bt_daxdev)) return -EOPNOTSUPP; file_accessed(file); vma->vm_ops = &xfs_file_vm_ops; if (IS_DAX(inode)) vma->vm_flags |= VM_HUGEPAGE; return 0; } const struct file_operations xfs_file_operations = { .llseek = xfs_file_llseek, .read_iter = xfs_file_read_iter, .write_iter = xfs_file_write_iter, .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .iopoll = iomap_dio_iopoll, .unlocked_ioctl = xfs_file_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = xfs_file_compat_ioctl, #endif .mmap = xfs_file_mmap, .mmap_supported_flags = MAP_SYNC, .open = xfs_file_open, .release = xfs_file_release, .fsync = xfs_file_fsync, .get_unmapped_area = thp_get_unmapped_area, .fallocate = xfs_file_fallocate, .fadvise = xfs_file_fadvise, .remap_file_range = xfs_file_remap_range, }; const struct file_operations xfs_dir_file_operations = { .open = xfs_dir_open, .read = generic_read_dir, .iterate_shared = xfs_file_readdir, .llseek = generic_file_llseek, .unlocked_ioctl = xfs_file_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = xfs_file_compat_ioctl, #endif .fsync = xfs_dir_fsync, };