| /* |
| * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
| * All Rights Reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| #include "xfs.h" |
| #include "xfs_fs.h" |
| #include "xfs_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 <linux/dcache.h> |
| #include <linux/falloc.h> |
| #include <linux/pagevec.h> |
| #include <linux/backing-dev.h> |
| |
| static const struct vm_operations_struct xfs_file_vm_ops; |
| |
| /* |
| * Locking primitives for read and write IO paths to ensure we consistently use |
| * and order the inode->i_mutex, ip->i_lock and ip->i_iolock. |
| */ |
| static inline void |
| xfs_rw_ilock( |
| struct xfs_inode *ip, |
| int type) |
| { |
| if (type & XFS_IOLOCK_EXCL) |
| inode_lock(VFS_I(ip)); |
| xfs_ilock(ip, type); |
| } |
| |
| static inline void |
| xfs_rw_iunlock( |
| struct xfs_inode *ip, |
| int type) |
| { |
| xfs_iunlock(ip, type); |
| if (type & XFS_IOLOCK_EXCL) |
| inode_unlock(VFS_I(ip)); |
| } |
| |
| static inline void |
| xfs_rw_ilock_demote( |
| struct xfs_inode *ip, |
| int type) |
| { |
| xfs_ilock_demote(ip, type); |
| if (type & XFS_IOLOCK_EXCL) |
| inode_unlock(VFS_I(ip)); |
| } |
| |
| /* |
| * xfs_iozero clears the specified range supplied via the page cache (except in |
| * the DAX case). Writes through the page cache will allocate blocks over holes, |
| * though the callers usually map the holes first and avoid them. If a block is |
| * not completely zeroed, then it will be read from disk before being partially |
| * zeroed. |
| * |
| * In the DAX case, we can just directly write to the underlying pages. This |
| * will not allocate blocks, but will avoid holes and unwritten extents and so |
| * not do unnecessary work. |
| */ |
| int |
| xfs_iozero( |
| struct xfs_inode *ip, /* inode */ |
| loff_t pos, /* offset in file */ |
| size_t count) /* size of data to zero */ |
| { |
| struct page *page; |
| struct address_space *mapping; |
| int status = 0; |
| |
| |
| mapping = VFS_I(ip)->i_mapping; |
| do { |
| unsigned offset, bytes; |
| void *fsdata; |
| |
| offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ |
| bytes = PAGE_CACHE_SIZE - offset; |
| if (bytes > count) |
| bytes = count; |
| |
| if (IS_DAX(VFS_I(ip))) { |
| status = dax_zero_page_range(VFS_I(ip), pos, bytes, |
| xfs_get_blocks_direct); |
| if (status) |
| break; |
| } else { |
| status = pagecache_write_begin(NULL, mapping, pos, bytes, |
| AOP_FLAG_UNINTERRUPTIBLE, |
| &page, &fsdata); |
| if (status) |
| break; |
| |
| zero_user(page, offset, bytes); |
| |
| status = pagecache_write_end(NULL, mapping, pos, bytes, |
| bytes, page, fsdata); |
| WARN_ON(status <= 0); /* can't return less than zero! */ |
| status = 0; |
| } |
| pos += bytes; |
| count -= bytes; |
| } while (count); |
| |
| return status; |
| } |
| |
| int |
| xfs_update_prealloc_flags( |
| struct xfs_inode *ip, |
| enum xfs_prealloc_flags flags) |
| { |
| struct xfs_trans *tp; |
| int error; |
| |
| tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID); |
| error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0); |
| if (error) { |
| xfs_trans_cancel(tp); |
| return error; |
| } |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); |
| |
| if (!(flags & XFS_PREALLOC_INVISIBLE)) { |
| ip->i_d.di_mode &= ~S_ISUID; |
| if (ip->i_d.di_mode & S_IXGRP) |
| ip->i_d.di_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 = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| if (error) |
| return error; |
| |
| if (XFS_FORCED_SHUTDOWN(mp)) |
| return -EIO; |
| |
| xfs_iflags_clear(ip, XFS_ITRUNCATED); |
| |
| if (mp->m_flags & XFS_MOUNT_BARRIER) { |
| /* |
| * If we have an RT and/or log subvolume we need to make sure |
| * to flush the write cache the device used for file data |
| * first. This is to ensure newly written file data make |
| * it to disk before logging the new inode size in case of |
| * an extending write. |
| */ |
| if (XFS_IS_REALTIME_INODE(ip)) |
| xfs_blkdev_issue_flush(mp->m_rtdev_targp); |
| else if (mp->m_logdev_targp != mp->m_ddev_targp) |
| xfs_blkdev_issue_flush(mp->m_ddev_targp); |
| } |
| |
| /* |
| * 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 ((mp->m_flags & XFS_MOUNT_BARRIER) && |
| mp->m_logdev_targp == mp->m_ddev_targp && |
| !XFS_IS_REALTIME_INODE(ip) && |
| !log_flushed) |
| xfs_blkdev_issue_flush(mp->m_ddev_targp); |
| |
| return error; |
| } |
| |
| STATIC ssize_t |
| xfs_file_read_iter( |
| struct kiocb *iocb, |
| struct iov_iter *to) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file->f_mapping->host; |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_mount *mp = ip->i_mount; |
| size_t size = iov_iter_count(to); |
| ssize_t ret = 0; |
| int ioflags = 0; |
| xfs_fsize_t n; |
| loff_t pos = iocb->ki_pos; |
| |
| XFS_STATS_INC(mp, xs_read_calls); |
| |
| if (unlikely(iocb->ki_flags & IOCB_DIRECT)) |
| ioflags |= XFS_IO_ISDIRECT; |
| if (file->f_mode & FMODE_NOCMTIME) |
| ioflags |= XFS_IO_INVIS; |
| |
| if ((ioflags & XFS_IO_ISDIRECT) && !IS_DAX(inode)) { |
| xfs_buftarg_t *target = |
| XFS_IS_REALTIME_INODE(ip) ? |
| mp->m_rtdev_targp : mp->m_ddev_targp; |
| /* DIO must be aligned to device logical sector size */ |
| if ((pos | size) & target->bt_logical_sectormask) { |
| if (pos == i_size_read(inode)) |
| return 0; |
| return -EINVAL; |
| } |
| } |
| |
| n = mp->m_super->s_maxbytes - pos; |
| if (n <= 0 || size == 0) |
| return 0; |
| |
| if (n < size) |
| size = n; |
| |
| if (XFS_FORCED_SHUTDOWN(mp)) |
| return -EIO; |
| |
| /* |
| * Locking is a bit tricky here. If we take an exclusive lock for direct |
| * IO, we effectively serialise all new concurrent read IO to this file |
| * and block it behind IO that is currently in progress because IO in |
| * progress holds the IO lock shared. We only need to hold the lock |
| * exclusive to blow away the page cache, so only take lock exclusively |
| * if the page cache needs invalidation. This allows the normal direct |
| * IO case of no page cache pages to proceeed concurrently without |
| * serialisation. |
| */ |
| xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); |
| if ((ioflags & XFS_IO_ISDIRECT) && inode->i_mapping->nrpages) { |
| xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); |
| xfs_rw_ilock(ip, XFS_IOLOCK_EXCL); |
| |
| /* |
| * The generic dio code only flushes the range of the particular |
| * I/O. Because we take an exclusive lock here, this whole |
| * sequence is considerably more expensive for us. This has a |
| * noticeable performance impact for any file with cached pages, |
| * even when outside of the range of the particular I/O. |
| * |
| * Hence, amortize the cost of the lock against a full file |
| * flush and reduce the chances of repeated iolock cycles going |
| * forward. |
| */ |
| if (inode->i_mapping->nrpages) { |
| ret = filemap_write_and_wait(VFS_I(ip)->i_mapping); |
| if (ret) { |
| xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL); |
| return ret; |
| } |
| |
| /* |
| * Invalidate whole pages. This can return an error if |
| * we fail to invalidate a page, but this should never |
| * happen on XFS. Warn if it does fail. |
| */ |
| ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping); |
| WARN_ON_ONCE(ret); |
| ret = 0; |
| } |
| xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); |
| } |
| |
| trace_xfs_file_read(ip, size, pos, ioflags); |
| |
| ret = generic_file_read_iter(iocb, to); |
| if (ret > 0) |
| XFS_STATS_ADD(mp, xs_read_bytes, ret); |
| |
| xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); |
| return ret; |
| } |
| |
| STATIC ssize_t |
| xfs_file_splice_read( |
| struct file *infilp, |
| loff_t *ppos, |
| struct pipe_inode_info *pipe, |
| size_t count, |
| unsigned int flags) |
| { |
| struct xfs_inode *ip = XFS_I(infilp->f_mapping->host); |
| int ioflags = 0; |
| ssize_t ret; |
| |
| XFS_STATS_INC(ip->i_mount, xs_read_calls); |
| |
| if (infilp->f_mode & FMODE_NOCMTIME) |
| ioflags |= XFS_IO_INVIS; |
| |
| if (XFS_FORCED_SHUTDOWN(ip->i_mount)) |
| return -EIO; |
| |
| trace_xfs_file_splice_read(ip, count, *ppos, ioflags); |
| |
| /* |
| * DAX inodes cannot ues the page cache for splice, so we have to push |
| * them through the VFS IO path. This means it goes through |
| * ->read_iter, which for us takes the XFS_IOLOCK_SHARED. Hence we |
| * cannot lock the splice operation at this level for DAX inodes. |
| */ |
| if (IS_DAX(VFS_I(ip))) { |
| ret = default_file_splice_read(infilp, ppos, pipe, count, |
| flags); |
| goto out; |
| } |
| |
| xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); |
| ret = generic_file_splice_read(infilp, ppos, pipe, count, flags); |
| xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); |
| out: |
| if (ret > 0) |
| XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret); |
| return ret; |
| } |
| |
| /* |
| * This routine is called to handle zeroing any space in the last block of the |
| * file that is beyond the EOF. We do this since the size is being increased |
| * without writing anything to that block and we don't want to read the |
| * garbage on the disk. |
| */ |
| STATIC int /* error (positive) */ |
| xfs_zero_last_block( |
| struct xfs_inode *ip, |
| xfs_fsize_t offset, |
| xfs_fsize_t isize, |
| bool *did_zeroing) |
| { |
| struct xfs_mount *mp = ip->i_mount; |
| xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize); |
| int zero_offset = XFS_B_FSB_OFFSET(mp, isize); |
| int zero_len; |
| int nimaps = 1; |
| int error = 0; |
| struct xfs_bmbt_irec imap; |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0); |
| xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| if (error) |
| return error; |
| |
| ASSERT(nimaps > 0); |
| |
| /* |
| * If the block underlying isize is just a hole, then there |
| * is nothing to zero. |
| */ |
| if (imap.br_startblock == HOLESTARTBLOCK) |
| return 0; |
| |
| zero_len = mp->m_sb.sb_blocksize - zero_offset; |
| if (isize + zero_len > offset) |
| zero_len = offset - isize; |
| *did_zeroing = true; |
| return xfs_iozero(ip, isize, zero_len); |
| } |
| |
| /* |
| * Zero any on disk space between the current EOF and the new, larger EOF. |
| * |
| * This handles the normal case of zeroing the remainder of the last block in |
| * the file and the unusual case of zeroing blocks out beyond the size of the |
| * file. This second case only happens with fixed size extents and when the |
| * system crashes before the inode size was updated but after blocks were |
| * allocated. |
| * |
| * Expects the iolock to be held exclusive, and will take the ilock internally. |
| */ |
| int /* error (positive) */ |
| xfs_zero_eof( |
| struct xfs_inode *ip, |
| xfs_off_t offset, /* starting I/O offset */ |
| xfs_fsize_t isize, /* current inode size */ |
| bool *did_zeroing) |
| { |
| struct xfs_mount *mp = ip->i_mount; |
| xfs_fileoff_t start_zero_fsb; |
| xfs_fileoff_t end_zero_fsb; |
| xfs_fileoff_t zero_count_fsb; |
| xfs_fileoff_t last_fsb; |
| xfs_fileoff_t zero_off; |
| xfs_fsize_t zero_len; |
| int nimaps; |
| int error = 0; |
| struct xfs_bmbt_irec imap; |
| |
| ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); |
| ASSERT(offset > isize); |
| |
| trace_xfs_zero_eof(ip, isize, offset - isize); |
| |
| /* |
| * First handle zeroing the block on which isize resides. |
| * |
| * We only zero a part of that block so it is handled specially. |
| */ |
| if (XFS_B_FSB_OFFSET(mp, isize) != 0) { |
| error = xfs_zero_last_block(ip, offset, isize, did_zeroing); |
| if (error) |
| return error; |
| } |
| |
| /* |
| * Calculate the range between the new size and the old where blocks |
| * needing to be zeroed may exist. |
| * |
| * To get the block where the last byte in the file currently resides, |
| * we need to subtract one from the size and truncate back to a block |
| * boundary. We subtract 1 in case the size is exactly on a block |
| * boundary. |
| */ |
| last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1; |
| start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize); |
| end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1); |
| ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb); |
| if (last_fsb == end_zero_fsb) { |
| /* |
| * The size was only incremented on its last block. |
| * We took care of that above, so just return. |
| */ |
| return 0; |
| } |
| |
| ASSERT(start_zero_fsb <= end_zero_fsb); |
| while (start_zero_fsb <= end_zero_fsb) { |
| nimaps = 1; |
| zero_count_fsb = end_zero_fsb - start_zero_fsb + 1; |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb, |
| &imap, &nimaps, 0); |
| xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| if (error) |
| return error; |
| |
| ASSERT(nimaps > 0); |
| |
| if (imap.br_state == XFS_EXT_UNWRITTEN || |
| imap.br_startblock == HOLESTARTBLOCK) { |
| start_zero_fsb = imap.br_startoff + imap.br_blockcount; |
| ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); |
| continue; |
| } |
| |
| /* |
| * There are blocks we need to zero. |
| */ |
| zero_off = XFS_FSB_TO_B(mp, start_zero_fsb); |
| zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount); |
| |
| if ((zero_off + zero_len) > offset) |
| zero_len = offset - zero_off; |
| |
| error = xfs_iozero(ip, zero_off, zero_len); |
| if (error) |
| return error; |
| |
| *did_zeroing = true; |
| start_zero_fsb = imap.br_startoff + imap.br_blockcount; |
| ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * 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; |
| |
| restart: |
| error = generic_write_checks(iocb, from); |
| if (error <= 0) |
| return error; |
| |
| error = xfs_break_layouts(inode, iolock, true); |
| if (error) |
| return error; |
| |
| /* For changing security info in file_remove_privs() we need i_mutex */ |
| if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) { |
| xfs_rw_iunlock(ip, *iolock); |
| *iolock = XFS_IOLOCK_EXCL; |
| xfs_rw_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); |
| if (iocb->ki_pos > i_size_read(inode)) { |
| bool zero = false; |
| |
| spin_unlock(&ip->i_flags_lock); |
| if (!drained_dio) { |
| if (*iolock == XFS_IOLOCK_SHARED) { |
| xfs_rw_iunlock(ip, *iolock); |
| *iolock = XFS_IOLOCK_EXCL; |
| xfs_rw_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; |
| } |
| error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero); |
| 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; |
| } |
| |
| /* |
| * 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); |
| loff_t pos = iocb->ki_pos; |
| loff_t end; |
| struct iov_iter data; |
| 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 (!IS_DAX(inode) && ((pos | count) & target->bt_logical_sectormask)) |
| return -EINVAL; |
| |
| /* "unaligned" here means not aligned to a filesystem block */ |
| if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask)) |
| unaligned_io = 1; |
| |
| /* |
| * We don't need to take an exclusive lock unless there page cache needs |
| * to be invalidated or unaligned IO is being executed. We don't need to |
| * consider the EOF extension case here because |
| * xfs_file_aio_write_checks() will relock the inode as necessary for |
| * EOF zeroing cases and fill out the new inode size as appropriate. |
| */ |
| if (unaligned_io || mapping->nrpages) |
| iolock = XFS_IOLOCK_EXCL; |
| else |
| iolock = XFS_IOLOCK_SHARED; |
| xfs_rw_ilock(ip, iolock); |
| |
| /* |
| * Recheck if there are cached pages that need invalidate after we got |
| * the iolock to protect against other threads adding new pages while |
| * we were waiting for the iolock. |
| */ |
| if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) { |
| xfs_rw_iunlock(ip, iolock); |
| iolock = XFS_IOLOCK_EXCL; |
| xfs_rw_ilock(ip, iolock); |
| } |
| |
| ret = xfs_file_aio_write_checks(iocb, from, &iolock); |
| if (ret) |
| goto out; |
| count = iov_iter_count(from); |
| pos = iocb->ki_pos; |
| end = pos + count - 1; |
| |
| /* |
| * See xfs_file_read_iter() for why we do a full-file flush here. |
| */ |
| if (mapping->nrpages) { |
| ret = filemap_write_and_wait(VFS_I(ip)->i_mapping); |
| if (ret) |
| goto out; |
| /* |
| * Invalidate whole pages. This can return an error if we fail |
| * to invalidate a page, but this should never happen on XFS. |
| * Warn if it does fail. |
| */ |
| ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping); |
| WARN_ON_ONCE(ret); |
| ret = 0; |
| } |
| |
| /* |
| * If we are doing unaligned IO, wait for all other IO to drain, |
| * otherwise demote the lock if we had to flush cached pages |
| */ |
| if (unaligned_io) |
| inode_dio_wait(inode); |
| else if (iolock == XFS_IOLOCK_EXCL) { |
| xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); |
| iolock = XFS_IOLOCK_SHARED; |
| } |
| |
| trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0); |
| |
| data = *from; |
| ret = mapping->a_ops->direct_IO(iocb, &data, pos); |
| |
| /* see generic_file_direct_write() for why this is necessary */ |
| if (mapping->nrpages) { |
| invalidate_inode_pages2_range(mapping, |
| pos >> PAGE_CACHE_SHIFT, |
| end >> PAGE_CACHE_SHIFT); |
| } |
| |
| if (ret > 0) { |
| pos += ret; |
| iov_iter_advance(from, ret); |
| iocb->ki_pos = pos; |
| } |
| out: |
| xfs_rw_iunlock(ip, iolock); |
| |
| /* |
| * No fallback to buffered IO on errors for XFS. DAX can result in |
| * partial writes, but direct IO will either complete fully or fail. |
| */ |
| ASSERT(ret < 0 || ret == count || IS_DAX(VFS_I(ip))); |
| 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 = XFS_IOLOCK_EXCL; |
| |
| xfs_rw_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); |
| |
| write_retry: |
| trace_xfs_file_buffered_write(ip, iov_iter_count(from), |
| iocb->ki_pos, 0); |
| ret = generic_perform_write(file, from, iocb->ki_pos); |
| 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) { |
| enospc = xfs_inode_free_quota_eofblocks(ip); |
| if (enospc) |
| goto write_retry; |
| } else if (ret == -ENOSPC && !enospc) { |
| struct xfs_eofblocks eofb = {0}; |
| |
| enospc = 1; |
| xfs_flush_inodes(ip->i_mount); |
| eofb.eof_scan_owner = ip->i_ino; /* for locking */ |
| eofb.eof_flags = XFS_EOF_FLAGS_SYNC; |
| xfs_icache_free_eofblocks(ip->i_mount, &eofb); |
| goto write_retry; |
| } |
| |
| current->backing_dev_info = NULL; |
| out: |
| xfs_rw_iunlock(ip, iolock); |
| 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 ((iocb->ki_flags & IOCB_DIRECT) || IS_DAX(inode)) |
| ret = xfs_file_dio_aio_write(iocb, from); |
| else |
| ret = xfs_file_buffered_aio_write(iocb, from); |
| |
| if (ret > 0) { |
| ssize_t err; |
| |
| XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret); |
| |
| /* Handle various SYNC-type writes */ |
| err = generic_write_sync(file, iocb->ki_pos - ret, ret); |
| if (err < 0) |
| ret = err; |
| } |
| return ret; |
| } |
| |
| #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) |
| |
| 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; |
| loff_t new_size = 0; |
| bool do_file_insert = 0; |
| |
| 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, false); |
| if (error) |
| goto out_unlock; |
| |
| xfs_ilock(ip, XFS_MMAPLOCK_EXCL); |
| iolock |= XFS_MMAPLOCK_EXCL; |
| |
| 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 blksize_mask = (1 << inode->i_blkbits) - 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 blksize_mask = (1 << inode->i_blkbits) - 1; |
| |
| new_size = i_size_read(inode) + len; |
| if (offset & blksize_mask || len & blksize_mask) { |
| error = -EINVAL; |
| goto out_unlock; |
| } |
| |
| /* check the new inode size does not wrap through zero */ |
| if (new_size > inode->i_sb->s_maxbytes) { |
| error = -EFBIG; |
| goto out_unlock; |
| } |
| |
| /* Offset should be less than i_size */ |
| if (offset >= i_size_read(inode)) { |
| error = -EINVAL; |
| goto out_unlock; |
| } |
| do_file_insert = 1; |
| } 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 |
| 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_setattr_size(ip, &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_open( |
| struct inode *inode, |
| struct file *file) |
| { |
| if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) |
| return -EFBIG; |
| if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb))) |
| return -EIO; |
| return 0; |
| } |
| |
| STATIC int |
| xfs_dir_open( |
| struct inode *inode, |
| struct file *file) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| int mode; |
| int error; |
| |
| error = xfs_file_open(inode, file); |
| if (error) |
| return error; |
| |
| /* |
| * If there are any blocks, read-ahead block 0 as we're almost |
| * certain to have the next operation be a read there. |
| */ |
| mode = xfs_ilock_data_map_shared(ip); |
| if (ip->i_d.di_nextents > 0) |
| xfs_dir3_data_readahead(ip, 0, -1); |
| xfs_iunlock(ip, mode); |
| return 0; |
| } |
| |
| STATIC int |
| xfs_file_release( |
| struct inode *inode, |
| struct file *filp) |
| { |
| return xfs_release(XFS_I(inode)); |
| } |
| |
| STATIC int |
| xfs_file_readdir( |
| struct file *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, 32768, ip->i_d.di_size); |
| |
| return xfs_readdir(ip, ctx, bufsize); |
| } |
| |
| /* |
| * This type is designed to indicate the type of offset we would like |
| * to search from page cache for xfs_seek_hole_data(). |
| */ |
| enum { |
| HOLE_OFF = 0, |
| DATA_OFF, |
| }; |
| |
| /* |
| * Lookup the desired type of offset from the given page. |
| * |
| * On success, return true and the offset argument will point to the |
| * start of the region that was found. Otherwise this function will |
| * return false and keep the offset argument unchanged. |
| */ |
| STATIC bool |
| xfs_lookup_buffer_offset( |
| struct page *page, |
| loff_t *offset, |
| unsigned int type) |
| { |
| loff_t lastoff = page_offset(page); |
| bool found = false; |
| struct buffer_head *bh, *head; |
| |
| bh = head = page_buffers(page); |
| do { |
| /* |
| * Unwritten extents that have data in the page |
| * cache covering them can be identified by the |
| * BH_Unwritten state flag. Pages with multiple |
| * buffers might have a mix of holes, data and |
| * unwritten extents - any buffer with valid |
| * data in it should have BH_Uptodate flag set |
| * on it. |
| */ |
| if (buffer_unwritten(bh) || |
| buffer_uptodate(bh)) { |
| if (type == DATA_OFF) |
| found = true; |
| } else { |
| if (type == HOLE_OFF) |
| found = true; |
| } |
| |
| if (found) { |
| *offset = lastoff; |
| break; |
| } |
| lastoff += bh->b_size; |
| } while ((bh = bh->b_this_page) != head); |
| |
| return found; |
| } |
| |
| /* |
| * This routine is called to find out and return a data or hole offset |
| * from the page cache for unwritten extents according to the desired |
| * type for xfs_seek_hole_data(). |
| * |
| * The argument offset is used to tell where we start to search from the |
| * page cache. Map is used to figure out the end points of the range to |
| * lookup pages. |
| * |
| * Return true if the desired type of offset was found, and the argument |
| * offset is filled with that address. Otherwise, return false and keep |
| * offset unchanged. |
| */ |
| STATIC bool |
| xfs_find_get_desired_pgoff( |
| struct inode *inode, |
| struct xfs_bmbt_irec *map, |
| unsigned int type, |
| loff_t *offset) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_mount *mp = ip->i_mount; |
| struct pagevec pvec; |
| pgoff_t index; |
| pgoff_t end; |
| loff_t endoff; |
| loff_t startoff = *offset; |
| loff_t lastoff = startoff; |
| bool found = false; |
| |
| pagevec_init(&pvec, 0); |
| |
| index = startoff >> PAGE_CACHE_SHIFT; |
| endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount); |
| end = endoff >> PAGE_CACHE_SHIFT; |
| do { |
| int want; |
| unsigned nr_pages; |
| unsigned int i; |
| |
| want = min_t(pgoff_t, end - index, PAGEVEC_SIZE); |
| nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index, |
| want); |
| /* |
| * No page mapped into given range. If we are searching holes |
| * and if this is the first time we got into the loop, it means |
| * that the given offset is landed in a hole, return it. |
| * |
| * If we have already stepped through some block buffers to find |
| * holes but they all contains data. In this case, the last |
| * offset is already updated and pointed to the end of the last |
| * mapped page, if it does not reach the endpoint to search, |
| * that means there should be a hole between them. |
| */ |
| if (nr_pages == 0) { |
| /* Data search found nothing */ |
| if (type == DATA_OFF) |
| break; |
| |
| ASSERT(type == HOLE_OFF); |
| if (lastoff == startoff || lastoff < endoff) { |
| found = true; |
| *offset = lastoff; |
| } |
| break; |
| } |
| |
| /* |
| * At lease we found one page. If this is the first time we |
| * step into the loop, and if the first page index offset is |
| * greater than the given search offset, a hole was found. |
| */ |
| if (type == HOLE_OFF && lastoff == startoff && |
| lastoff < page_offset(pvec.pages[0])) { |
| found = true; |
| break; |
| } |
| |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| loff_t b_offset; |
| |
| /* |
| * At this point, the page may be truncated or |
| * invalidated (changing page->mapping to NULL), |
| * or even swizzled back from swapper_space to tmpfs |
| * file mapping. However, page->index will not change |
| * because we have a reference on the page. |
| * |
| * Searching done if the page index is out of range. |
| * If the current offset is not reaches the end of |
| * the specified search range, there should be a hole |
| * between them. |
| */ |
| if (page->index > end) { |
| if (type == HOLE_OFF && lastoff < endoff) { |
| *offset = lastoff; |
| found = true; |
| } |
| goto out; |
| } |
| |
| lock_page(page); |
| /* |
| * Page truncated or invalidated(page->mapping == NULL). |
| * We can freely skip it and proceed to check the next |
| * page. |
| */ |
| if (unlikely(page->mapping != inode->i_mapping)) { |
| unlock_page(page); |
| continue; |
| } |
| |
| if (!page_has_buffers(page)) { |
| unlock_page(page); |
| continue; |
| } |
| |
| found = xfs_lookup_buffer_offset(page, &b_offset, type); |
| if (found) { |
| /* |
| * The found offset may be less than the start |
| * point to search if this is the first time to |
| * come here. |
| */ |
| *offset = max_t(loff_t, startoff, b_offset); |
| unlock_page(page); |
| goto out; |
| } |
| |
| /* |
| * We either searching data but nothing was found, or |
| * searching hole but found a data buffer. In either |
| * case, probably the next page contains the desired |
| * things, update the last offset to it so. |
| */ |
| lastoff = page_offset(page) + PAGE_SIZE; |
| unlock_page(page); |
| } |
| |
| /* |
| * The number of returned pages less than our desired, search |
| * done. In this case, nothing was found for searching data, |
| * but we found a hole behind the last offset. |
| */ |
| if (nr_pages < want) { |
| if (type == HOLE_OFF) { |
| *offset = lastoff; |
| found = true; |
| } |
| break; |
| } |
| |
| index = pvec.pages[i - 1]->index + 1; |
| pagevec_release(&pvec); |
| } while (index <= end); |
| |
| out: |
| pagevec_release(&pvec); |
| return found; |
| } |
| |
| /* |
| * caller must lock inode with xfs_ilock_data_map_shared, |
| * can we craft an appropriate ASSERT? |
| * |
| * end is because the VFS-level lseek interface is defined such that any |
| * offset past i_size shall return -ENXIO, but we use this for quota code |
| * which does not maintain i_size, and we want to SEEK_DATA past i_size. |
| */ |
| loff_t |
| __xfs_seek_hole_data( |
| struct inode *inode, |
| loff_t start, |
| loff_t end, |
| int whence) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_mount *mp = ip->i_mount; |
| loff_t uninitialized_var(offset); |
| xfs_fileoff_t fsbno; |
| xfs_filblks_t lastbno; |
| int error; |
| |
| if (start >= end) { |
| error = -ENXIO; |
| goto out_error; |
| } |
| |
| /* |
| * Try to read extents from the first block indicated |
| * by fsbno to the end block of the file. |
| */ |
| fsbno = XFS_B_TO_FSBT(mp, start); |
| lastbno = XFS_B_TO_FSB(mp, end); |
| |
| for (;;) { |
| struct xfs_bmbt_irec map[2]; |
| int nmap = 2; |
| unsigned int i; |
| |
| error = xfs_bmapi_read(ip, fsbno, lastbno - fsbno, map, &nmap, |
| XFS_BMAPI_ENTIRE); |
| if (error) |
| goto out_error; |
| |
| /* No extents at given offset, must be beyond EOF */ |
| if (nmap == 0) { |
| error = -ENXIO; |
| goto out_error; |
| } |
| |
| for (i = 0; i < nmap; i++) { |
| offset = max_t(loff_t, start, |
| XFS_FSB_TO_B(mp, map[i].br_startoff)); |
| |
| /* Landed in the hole we wanted? */ |
| if (whence == SEEK_HOLE && |
| map[i].br_startblock == HOLESTARTBLOCK) |
| goto out; |
| |
| /* Landed in the data extent we wanted? */ |
| if (whence == SEEK_DATA && |
| (map[i].br_startblock == DELAYSTARTBLOCK || |
| (map[i].br_state == XFS_EXT_NORM && |
| !isnullstartblock(map[i].br_startblock)))) |
| goto out; |
| |
| /* |
| * Landed in an unwritten extent, try to search |
| * for hole or data from page cache. |
| */ |
| if (map[i].br_state == XFS_EXT_UNWRITTEN) { |
| if (xfs_find_get_desired_pgoff(inode, &map[i], |
| whence == SEEK_HOLE ? HOLE_OFF : DATA_OFF, |
| &offset)) |
| goto out; |
| } |
| } |
| |
| /* |
| * We only received one extent out of the two requested. This |
| * means we've hit EOF and didn't find what we are looking for. |
| */ |
| if (nmap == 1) { |
| /* |
| * If we were looking for a hole, set offset to |
| * the end of the file (i.e., there is an implicit |
| * hole at the end of any file). |
| */ |
| if (whence == SEEK_HOLE) { |
| offset = end; |
| break; |
| } |
| /* |
| * If we were looking for data, it's nowhere to be found |
| */ |
| ASSERT(whence == SEEK_DATA); |
| error = -ENXIO; |
| goto out_error; |
| } |
| |
| ASSERT(i > 1); |
| |
| /* |
| * Nothing was found, proceed to the next round of search |
| * if the next reading offset is not at or beyond EOF. |
| */ |
| fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount; |
| start = XFS_FSB_TO_B(mp, fsbno); |
| if (start >= end) { |
| if (whence == SEEK_HOLE) { |
| offset = end; |
| break; |
| } |
| ASSERT(whence == SEEK_DATA); |
| error = -ENXIO; |
| goto out_error; |
| } |
| } |
| |
| out: |
| /* |
| * If at this point we have found the hole we wanted, the returned |
| * offset may be bigger than the file size as it may be aligned to |
| * page boundary for unwritten extents. We need to deal with this |
| * situation in particular. |
| */ |
| if (whence == SEEK_HOLE) |
| offset = min_t(loff_t, offset, end); |
| |
| return offset; |
| |
| out_error: |
| return error; |
| } |
| |
| STATIC loff_t |
| xfs_seek_hole_data( |
| struct file *file, |
| loff_t start, |
| int whence) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_mount *mp = ip->i_mount; |
| uint lock; |
| loff_t offset, end; |
| int error = 0; |
| |
| if (XFS_FORCED_SHUTDOWN(mp)) |
| return -EIO; |
| |
| lock = xfs_ilock_data_map_shared(ip); |
| |
| end = i_size_read(inode); |
| offset = __xfs_seek_hole_data(inode, start, end, whence); |
| if (offset < 0) { |
| error = offset; |
| goto out_unlock; |
| } |
| |
| offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes); |
| |
| out_unlock: |
| xfs_iunlock(ip, lock); |
| |
| if (error) |
| return error; |
| return offset; |
| } |
| |
| STATIC loff_t |
| xfs_file_llseek( |
| struct file *file, |
| loff_t offset, |
| int whence) |
| { |
| switch (whence) { |
| case SEEK_END: |
| case SEEK_CUR: |
| case SEEK_SET: |
| return generic_file_llseek(file, offset, whence); |
| case SEEK_HOLE: |
| case SEEK_DATA: |
| return xfs_seek_hole_data(file, offset, whence); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| /* |
| * 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) |
| */ |
| |
| /* |
| * mmap()d file has taken write protection fault and is being made writable. We |
| * can set the page state up correctly for a writable page, which means we can |
| * do correct delalloc accounting (ENOSPC checking!) and unwritten extent |
| * mapping. |
| */ |
| STATIC int |
| xfs_filemap_page_mkwrite( |
| struct vm_area_struct *vma, |
| struct vm_fault *vmf) |
| { |
| struct inode *inode = file_inode(vma->vm_file); |
| int ret; |
| |
| trace_xfs_filemap_page_mkwrite(XFS_I(inode)); |
| |
| sb_start_pagefault(inode->i_sb); |
| file_update_time(vma->vm_file); |
| xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); |
| |
| if (IS_DAX(inode)) { |
| ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault, NULL); |
| } else { |
| ret = block_page_mkwrite(vma, vmf, xfs_get_blocks); |
| ret = block_page_mkwrite_return(ret); |
| } |
| |
| xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); |
| sb_end_pagefault(inode->i_sb); |
| |
| return ret; |
| } |
| |
| STATIC int |
| xfs_filemap_fault( |
| struct vm_area_struct *vma, |
| struct vm_fault *vmf) |
| { |
| struct inode *inode = file_inode(vma->vm_file); |
| int ret; |
| |
| trace_xfs_filemap_fault(XFS_I(inode)); |
| |
| /* DAX can shortcut the normal fault path on write faults! */ |
| if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(inode)) |
| return xfs_filemap_page_mkwrite(vma, vmf); |
| |
| xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); |
| if (IS_DAX(inode)) { |
| /* |
| * we do not want to trigger unwritten extent conversion on read |
| * faults - that is unnecessary overhead and would also require |
| * changes to xfs_get_blocks_direct() to map unwritten extent |
| * ioend for conversion on read-only mappings. |
| */ |
| ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault, NULL); |
| } else |
| ret = filemap_fault(vma, vmf); |
| xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); |
| |
| return ret; |
| } |
| |
| /* |
| * Similar to xfs_filemap_fault(), the DAX fault path can call into here on |
| * both read and write faults. Hence we need to handle both cases. There is no |
| * ->pmd_mkwrite callout for huge pages, so we have a single function here to |
| * handle both cases here. @flags carries the information on the type of fault |
| * occuring. |
| */ |
| STATIC int |
| xfs_filemap_pmd_fault( |
| struct vm_area_struct *vma, |
| unsigned long addr, |
| pmd_t *pmd, |
| unsigned int flags) |
| { |
| struct inode *inode = file_inode(vma->vm_file); |
| struct xfs_inode *ip = XFS_I(inode); |
| int ret; |
| |
| if (!IS_DAX(inode)) |
| return VM_FAULT_FALLBACK; |
| |
| trace_xfs_filemap_pmd_fault(ip); |
| |
| if (flags & FAULT_FLAG_WRITE) { |
| sb_start_pagefault(inode->i_sb); |
| file_update_time(vma->vm_file); |
| } |
| |
| xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); |
| ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault, |
| NULL); |
| xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); |
| |
| if (flags & FAULT_FLAG_WRITE) |
| sb_end_pagefault(inode->i_sb); |
| |
| return ret; |
| } |
| |
| /* |
| * pfn_mkwrite was originally inteneded to ensure we capture time stamp |
| * updates on write faults. In reality, it's need to serialise against |
| * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED |
| * to ensure we serialise the fault barrier in place. |
| */ |
| static int |
| xfs_filemap_pfn_mkwrite( |
| struct vm_area_struct *vma, |
| struct vm_fault *vmf) |
| { |
| |
| struct inode *inode = file_inode(vma->vm_file); |
| struct xfs_inode *ip = XFS_I(inode); |
| int ret = VM_FAULT_NOPAGE; |
| loff_t size; |
| |
| trace_xfs_filemap_pfn_mkwrite(ip); |
| |
| sb_start_pagefault(inode->i_sb); |
| file_update_time(vma->vm_file); |
| |
| /* check if the faulting page hasn't raced with truncate */ |
| xfs_ilock(ip, XFS_MMAPLOCK_SHARED); |
| size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| if (vmf->pgoff >= size) |
| ret = VM_FAULT_SIGBUS; |
| else if (IS_DAX(inode)) |
| ret = dax_pfn_mkwrite(vma, vmf); |
| xfs_iunlock(ip, XFS_MMAPLOCK_SHARED); |
| sb_end_pagefault(inode->i_sb); |
| return ret; |
| |
| } |
| |
| static const struct vm_operations_struct xfs_file_vm_ops = { |
| .fault = xfs_filemap_fault, |
| .pmd_fault = xfs_filemap_pmd_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) |
| { |
| file_accessed(filp); |
| vma->vm_ops = &xfs_file_vm_ops; |
| if (IS_DAX(file_inode(filp))) |
| vma->vm_flags |= VM_MIXEDMAP | 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 = xfs_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, |
| .open = xfs_file_open, |
| .release = xfs_file_release, |
| .fsync = xfs_file_fsync, |
| .fallocate = xfs_file_fallocate, |
| }; |
| |
| const struct file_operations xfs_dir_file_operations = { |
| .open = xfs_dir_open, |
| .read = generic_read_dir, |
| .iterate = 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, |
| }; |