From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/xfs/xfs_file.c | 1468 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1468 insertions(+) create mode 100644 fs/xfs/xfs_file.c (limited to 'fs/xfs/xfs_file.c') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c new file mode 100644 index 000000000..e462d39c8 --- /dev/null +++ b/fs/xfs/xfs_file.c @@ -0,0 +1,1468 @@ +// 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 +#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); +} + +/* + * 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, err2; + int log_flushed = 0; + + trace_xfs_file_fsync(ip); + + error = file_write_and_wait_range(file, start, end); + if (error) + return error; + + if (xfs_is_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)) + error = blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev); + else if (mp->m_logdev_targp != mp->m_ddev_targp) + error = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev); + + /* + * Any inode that has dirty modifications in the log is pinned. The + * racy check here for a pinned inode will not catch modifications + * that happen concurrently to the fsync call, but fsync semantics + * only require to sync previously completed I/O. + */ + if (xfs_ipincount(ip)) { + err2 = xfs_fsync_flush_log(ip, datasync, &log_flushed); + if (err2 && !error) + error = err2; + } + + /* + * 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) { + err2 = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev); + if (err2 && !error) + error = err2; + } + + return error; +} + +static int +xfs_ilock_iocb( + struct kiocb *iocb, + unsigned int lock_mode) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!xfs_ilock_nowait(ip, lock_mode)) + return -EAGAIN; + } else { + xfs_ilock(ip, lock_mode); + } + + return 0; +} + +STATIC ssize_t +xfs_file_dio_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_direct_read(iocb, to); + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + + file_accessed(iocb->ki_filp); + + ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED); + if (ret) + return ret; + ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, 0, NULL, 0); + 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); + ssize_t ret = 0; + + trace_xfs_file_dax_read(iocb, to); + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + + ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED); + if (ret) + return ret; + 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_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(iocb, to); + + ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED); + if (ret) + return ret; + 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_is_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_read(iocb, to); + else + ret = xfs_file_buffered_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_write_checks( + struct kiocb *iocb, + struct iov_iter *from, + unsigned 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; + + if (iocb->ki_flags & IOCB_NOWAIT) { + error = break_layout(inode, false); + if (error == -EWOULDBLOCK) + error = -EAGAIN; + } else { + 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; + error = xfs_ilock_iocb(iocb, *iolock); + if (error) { + *iolock = 0; + return error; + } + 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. + * + * We can do an unlocked check here safely as IO completion can only + * extend EOF. Truncate is locked out at this point, so the EOF can + * not move backwards, only forwards. Hence we only need to take the + * slow path and spin locks when we are at or beyond the current EOF. + */ + if (iocb->ki_pos <= i_size_read(inode)) + goto out; + + spin_lock(&ip->i_flags_lock); + isize = i_size_read(inode); + if (iocb->ki_pos > isize) { + spin_unlock(&ip->i_flags_lock); + + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + + 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 = xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL); + if (error) + return error; + } else + spin_unlock(&ip->i_flags_lock); + +out: + return kiocb_modified(iocb); +} + +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_is_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. + * + * As IO completion only ever extends EOF, we can do an unlocked check + * here to avoid taking the spinlock. If we land within the current EOF, + * then we do not need to do an extending update at all, and we don't + * need to take the lock to check this. If we race with an update moving + * EOF, then we'll either still be beyond EOF and need to take the lock, + * or we'll be within EOF and we don't need to take it at all. + */ + if (offset + size <= i_size_read(inode)) + goto out; + + 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, +}; + +/* + * Handle block aligned direct I/O writes + */ +static noinline ssize_t +xfs_file_dio_write_aligned( + struct xfs_inode *ip, + struct kiocb *iocb, + struct iov_iter *from) +{ + unsigned int iolock = XFS_IOLOCK_SHARED; + ssize_t ret; + + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + return ret; + ret = xfs_file_write_checks(iocb, from, &iolock); + if (ret) + goto out_unlock; + + /* + * We don't need to hold the IOLOCK exclusively across the IO, so demote + * the iolock back to shared if we had to take the exclusive lock in + * xfs_file_write_checks() for other reasons. + */ + if (iolock == XFS_IOLOCK_EXCL) { + xfs_ilock_demote(ip, XFS_IOLOCK_EXCL); + iolock = XFS_IOLOCK_SHARED; + } + trace_xfs_file_direct_write(iocb, from); + ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops, + &xfs_dio_write_ops, 0, NULL, 0); +out_unlock: + if (iolock) + xfs_iunlock(ip, iolock); + return ret; +} + +/* + * Handle block unaligned direct I/O writes + * + * In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing + * them to be done in parallel with reads and other direct I/O writes. However, + * if the I/O is not aligned to filesystem blocks, the direct I/O layer may need + * to do sub-block zeroing and that requires serialisation against other direct + * I/O to the same block. In this case we need to serialise the submission of + * the unaligned I/O so that we don't get racing block zeroing in the dio layer. + * In the case where sub-block zeroing is not required, we can do concurrent + * sub-block dios to the same block successfully. + * + * Optimistically submit the I/O using the shared lock first, but use the + * IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN + * if block allocation or partial block zeroing would be required. In that case + * we try again with the exclusive lock. + */ +static noinline ssize_t +xfs_file_dio_write_unaligned( + struct xfs_inode *ip, + struct kiocb *iocb, + struct iov_iter *from) +{ + size_t isize = i_size_read(VFS_I(ip)); + size_t count = iov_iter_count(from); + unsigned int iolock = XFS_IOLOCK_SHARED; + unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY; + ssize_t ret; + + /* + * Extending writes need exclusivity because of the sub-block zeroing + * that the DIO code always does for partial tail blocks beyond EOF, so + * don't even bother trying the fast path in this case. + */ + if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; +retry_exclusive: + iolock = XFS_IOLOCK_EXCL; + flags = IOMAP_DIO_FORCE_WAIT; + } + + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + return ret; + + /* + * 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(iocb, from); + ret = -ENOTBLK; + goto out_unlock; + } + + ret = xfs_file_write_checks(iocb, from, &iolock); + if (ret) + goto out_unlock; + + /* + * If we are doing exclusive unaligned I/O, this must be the only I/O + * in-flight. Otherwise we risk data corruption due to unwritten extent + * conversions from the AIO end_io handler. Wait for all other I/O to + * drain first. + */ + if (flags & IOMAP_DIO_FORCE_WAIT) + inode_dio_wait(VFS_I(ip)); + + trace_xfs_file_direct_write(iocb, from); + ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops, + &xfs_dio_write_ops, flags, NULL, 0); + + /* + * Retry unaligned I/O with exclusive blocking semantics if the DIO + * layer rejected it for mapping or locking reasons. If we are doing + * nonblocking user I/O, propagate the error. + */ + if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) { + ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY); + xfs_iunlock(ip, iolock); + goto retry_exclusive; + } + +out_unlock: + if (iolock) + xfs_iunlock(ip, iolock); + return ret; +} + +static ssize_t +xfs_file_dio_write( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp)); + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + size_t count = iov_iter_count(from); + + /* direct I/O must be aligned to device logical sector size */ + if ((iocb->ki_pos | count) & target->bt_logical_sectormask) + return -EINVAL; + if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask) + return xfs_file_dio_write_unaligned(ip, iocb, from); + return xfs_file_dio_write_aligned(ip, iocb, from); +} + +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); + unsigned int iolock = XFS_IOLOCK_EXCL; + ssize_t ret, error = 0; + loff_t pos; + + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + return ret; + ret = xfs_file_write_checks(iocb, from, &iolock); + if (ret) + goto out; + + pos = iocb->ki_pos; + + trace_xfs_file_dax_write(iocb, from); + ret = dax_iomap_rw(iocb, from, &xfs_dax_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: + if (iolock) + 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_write( + struct kiocb *iocb, + struct iov_iter *from) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + ssize_t ret; + bool cleared_space = false; + unsigned int iolock; + +write_retry: + iolock = XFS_IOLOCK_EXCL; + ret = xfs_ilock_iocb(iocb, iolock); + if (ret) + return ret; + + ret = xfs_file_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(iocb, from); + 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. Use a synchronous scan to increase the + * effectiveness of the scan. + */ + if (ret == -EDQUOT && !cleared_space) { + xfs_iunlock(ip, iolock); + xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC); + cleared_space = true; + goto write_retry; + } else if (ret == -ENOSPC && !cleared_space) { + struct xfs_icwalk icw = {0}; + + cleared_space = true; + xfs_flush_inodes(ip->i_mount); + + xfs_iunlock(ip, iolock); + icw.icw_flags = XFS_ICWALK_FLAG_SYNC; + xfs_blockgc_free_space(ip->i_mount, &icw); + 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 inode *inode = iocb->ki_filp->f_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_is_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_write(iocb, from); + if (ret != -ENOTBLK) + return ret; + } + + return xfs_file_buffered_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); +} + +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; + fallthrough; + 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; +} + +/* 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 (xfs_has_wsync(ip->i_mount)) + return true; + if (filp->f_flags & (__O_SYNC | O_DSYNC)) + return true; + if (IS_SYNC(file_inode(filp))) + return true; + + return false; +} + +#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; + 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; + } + + error = file_modified(file); + 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 { + 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); + 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_mnt_user_ns(file), + 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); + if (error) + goto out_unlock; + } + + if (xfs_file_sync_writes(file)) + error = xfs_log_force_inode(ip); + +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; +} + +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_has_reflink(mp)) + return -EOPNOTSUPP; + + if (xfs_is_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_diflags2 & XFS_DIFLAG2_COWEXTSIZE) && + pos_out == 0 && len >= i_size_read(inode_out) && + !(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)) + cowextsize = src->i_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 (xfs_is_shutdown(XFS_M(inode->i_sb))) + return -EIO; + file->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_BUF_WASYNC; + return generic_file_open(inode, file); +} + +STATIC int +xfs_dir_open( + struct inode *inode, + struct file *file) +{ + struct xfs_inode *ip = XFS_I(inode); + unsigned 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_disk_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_is_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); +} + +#ifdef CONFIG_FS_DAX +static inline vm_fault_t +xfs_dax_fault( + struct vm_fault *vmf, + enum page_entry_size pe_size, + bool write_fault, + pfn_t *pfn) +{ + return dax_iomap_fault(vmf, pe_size, pfn, NULL, + (write_fault && !vmf->cow_page) ? + &xfs_dax_write_iomap_ops : + &xfs_read_iomap_ops); +} +#else +static inline vm_fault_t +xfs_dax_fault( + struct vm_fault *vmf, + enum page_entry_size pe_size, + bool write_fault, + pfn_t *pfn) +{ + ASSERT(0); + return VM_FAULT_SIGBUS; +} +#endif + +/* + * Locking for serialisation of IO during page faults. This results in a lock + * ordering of: + * + * mmap_lock (MM) + * sb_start_pagefault(vfs, freeze) + * invalidate_lock (vfs/XFS_MMAPLOCK - 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); + } + + if (IS_DAX(inode)) { + pfn_t pfn; + + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + ret = xfs_dax_fault(vmf, pe_size, write_fault, &pfn); + if (ret & VM_FAULT_NEEDDSYNC) + ret = dax_finish_sync_fault(vmf, pe_size, pfn); + xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + } else { + if (write_fault) { + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + ret = iomap_page_mkwrite(vmf, + &xfs_buffered_write_iomap_ops); + xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + } else { + ret = filemap_fault(vmf); + } + } + + 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 vm_fault_t +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); + vm_fault_t ret; + + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + ret = filemap_map_pages(vmf, start_pgoff, end_pgoff); + xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); + return ret; +} + +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 = iocb_bio_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, +}; -- cgit v1.2.3