diff options
Diffstat (limited to 'fs/xfs/xfs_file.c')
| -rw-r--r-- | fs/xfs/xfs_file.c | 1207 |
1 files changed, 1207 insertions, 0 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c new file mode 100644 index 000000000..f22acfd53 --- /dev/null +++ b/fs/xfs/xfs_file.c @@ -0,0 +1,1207 @@ +// 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_da_format.h" +#include "xfs_da_btree.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_error.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 <linux/dcache.h> +#include <linux/falloc.h> +#include <linux/pagevec.h> +#include <linux/backing-dev.h> +#include <linux/mman.h> + +static const struct vm_operations_struct xfs_file_vm_ops; + +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); + struct xfs_mount *mp = ip->i_mount; + xfs_lsn_t lsn = 0; + + trace_xfs_dir_fsync(ip); + + xfs_ilock(ip, XFS_ILOCK_SHARED); + if (xfs_ipincount(ip)) + lsn = ip->i_itemp->ili_last_lsn; + xfs_iunlock(ip, XFS_ILOCK_SHARED); + + if (!lsn) + return 0; + return xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL); +} + +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; + int error = 0; + int log_flushed = 0; + xfs_lsn_t lsn = 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); + + /* + * 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 the 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. + */ + xfs_ilock(ip, XFS_ILOCK_SHARED); + if (xfs_ipincount(ip)) { + if (!datasync || + (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) + lsn = ip->i_itemp->ili_last_lsn; + } + + if (lsn) { + error = xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed); + ip->i_itemp->ili_fsync_fields = 0; + } + 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 (!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); + + xfs_ilock(ip, XFS_IOLOCK_SHARED); + ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL); + 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_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_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. + */ + if (likely(!(file->f_mode & FMODE_NOCMTIME))) { + error = file_update_time(file); + 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. + */ + if (!IS_NOSEC(inode)) + return file_remove_privs(file); + return 0; +} + +static int +xfs_dio_write_end_io( + struct kiocb *iocb, + ssize_t size, + unsigned flags) +{ + struct inode *inode = file_inode(iocb->ki_filp); + struct xfs_inode *ip = XFS_I(inode); + loff_t offset = iocb->ki_pos; + int error = 0; + + trace_xfs_end_io_direct_write(ip, offset, size); + + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; + + if (size <= 0) + return size; + + /* + * 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); + + if (flags & IOMAP_DIO_COW) { + error = xfs_reflink_end_cow(ip, offset, size); + if (error) + return error; + } + + /* + * 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) + return xfs_iomap_write_unwritten(ip, offset, size, true); + + /* + * 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); + } + + return error; +} + +/* + * 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_IS_REALTIME_INODE(ip) ? + mp->m_rtdev_targp : mp->m_ddev_targp; + + /* 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_reflink_inode(ip)) { + trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count); + return -EREMCHG; + } + 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); + ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io); + + /* + * If unaligned, this is the only IO in-flight. If it has not yet + * completed, wait on it before we release the iolock to prevent + * subsequent overlapping IO. + */ + if (ret == -EIOCBQUEUED && unaligned_io) + inode_dio_wait(inode); +out: + xfs_iunlock(ip, iolock); + + /* + * No fallback to buffered IO on errors for XFS, direct IO will either + * complete fully or fail. + */ + 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_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_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 != -EREMCHG) + 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; + + 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) { + unsigned int blksize_mask = i_blocksize(inode) - 1; + + if (offset & blksize_mask || len & blksize_mask) { + 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) { + unsigned int blksize_mask = i_blocksize(inode) - 1; + loff_t isize = i_size_read(inode); + + if (offset & blksize_mask || len & blksize_mask) { + 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) + error = xfs_zero_file_space(ip, offset, len); + else { + if (mode & FALLOC_FL_UNSHARE_RANGE) { + error = xfs_reflink_unshare(ip, offset, len); + if (error) + goto out_unlock; + } + 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_clone_range( + struct file *file_in, + loff_t pos_in, + struct file *file_out, + loff_t pos_out, + u64 len) +{ + return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out, + len, false); +} + +STATIC int +xfs_file_dedupe_range( + struct file *file_in, + loff_t pos_in, + struct file *file_out, + loff_t pos_out, + u64 len) +{ + return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out, + len, true); +} + +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; + 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_d.di_nextents > 0) + error = xfs_dir3_data_readahead(ip, 0, -1); + 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_iomap_ops); + break; + case SEEK_DATA: + offset = iomap_seek_data(inode, offset, &xfs_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_sem (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, &xfs_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_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 const struct vm_operations_struct xfs_file_vm_ops = { + .fault = xfs_filemap_fault, + .huge_fault = xfs_filemap_huge_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = xfs_filemap_page_mkwrite, + .pfn_mkwrite = xfs_filemap_pfn_mkwrite, +}; + +STATIC int +xfs_file_mmap( + struct file *filp, + struct vm_area_struct *vma) +{ + /* + * We don't support synchronous mappings for non-DAX files. At least + * until someone comes with a sensible use case. + */ + if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC)) + return -EOPNOTSUPP; + + file_accessed(filp); + vma->vm_ops = &xfs_file_vm_ops; + if (IS_DAX(file_inode(filp))) + 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, + .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, + .clone_file_range = xfs_file_clone_range, + .dedupe_file_range = xfs_file_dedupe_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, +}; |