--- /dev/null
+/*
+ * 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>
+
+static const struct vm_operations_struct xfs_file_vm_ops;
+
+/*
+ * Locking primitives for read and write IO paths to ensure we consistently use
+ * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
+ */
+static inline void
+xfs_rw_ilock(
+ struct xfs_inode *ip,
+ int type)
+{
+ if (type & XFS_IOLOCK_EXCL)
+ mutex_lock(&VFS_I(ip)->i_mutex);
+ xfs_ilock(ip, type);
+}
+
+static inline void
+xfs_rw_iunlock(
+ struct xfs_inode *ip,
+ int type)
+{
+ xfs_iunlock(ip, type);
+ if (type & XFS_IOLOCK_EXCL)
+ mutex_unlock(&VFS_I(ip)->i_mutex);
+}
+
+static inline void
+xfs_rw_ilock_demote(
+ struct xfs_inode *ip,
+ int type)
+{
+ xfs_ilock_demote(ip, type);
+ if (type & XFS_IOLOCK_EXCL)
+ mutex_unlock(&VFS_I(ip)->i_mutex);
+}
+
+/*
+ * xfs_iozero
+ *
+ * xfs_iozero clears the specified range of buffer supplied,
+ * and marks all the affected blocks as valid and modified. If
+ * an affected block is not allocated, it will be allocated. If
+ * an affected block is not completely overwritten, and is not
+ * valid before the operation, it will be read from disk before
+ * being partially zeroed.
+ */
+int
+xfs_iozero(
+ struct xfs_inode *ip, /* inode */
+ loff_t pos, /* offset in file */
+ size_t count) /* size of data to zero */
+{
+ struct page *page;
+ struct address_space *mapping;
+ int status;
+
+ mapping = VFS_I(ip)->i_mapping;
+ do {
+ unsigned offset, bytes;
+ void *fsdata;
+
+ offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
+ bytes = PAGE_CACHE_SIZE - offset;
+ if (bytes > count)
+ bytes = count;
+
+ status = pagecache_write_begin(NULL, mapping, pos, bytes,
+ AOP_FLAG_UNINTERRUPTIBLE,
+ &page, &fsdata);
+ if (status)
+ break;
+
+ zero_user(page, offset, bytes);
+
+ status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
+ page, fsdata);
+ WARN_ON(status <= 0); /* can't return less than zero! */
+ pos += bytes;
+ count -= bytes;
+ status = 0;
+ } while (count);
+
+ return status;
+}
+
+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, 0);
+ 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, 0);
+}
+
+/*
+ * 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.
+ */
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ if (xfs_ipincount(ip)) {
+ if (!datasync ||
+ (ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
+ lsn = ip->i_itemp->ili_last_lsn;
+ }
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+ if (lsn)
+ error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
+
+ /*
+ * If we only have a single device, and the log force about was
+ * a no-op we might have to flush the data device cache here.
+ * This can only happen for fdatasync/O_DSYNC if we were overwriting
+ * an already allocated file and thus do not have any metadata to
+ * commit.
+ */
+ if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
+ mp->m_logdev_targp == mp->m_ddev_targp &&
+ !XFS_IS_REALTIME_INODE(ip) &&
+ !log_flushed)
+ xfs_blkdev_issue_flush(mp->m_ddev_targp);
+
+ return error;
+}
+
+STATIC ssize_t
+xfs_file_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(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 (unlikely(ioflags & XFS_IO_ISDIRECT)) {
+ 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);
+
+ if (inode->i_mapping->nrpages) {
+ ret = filemap_write_and_wait_range(
+ VFS_I(ip)->i_mapping,
+ pos, pos + size - 1);
+ 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_range(VFS_I(ip)->i_mapping,
+ pos >> PAGE_CACHE_SHIFT,
+ (pos + size - 1) >> PAGE_CACHE_SHIFT);
+ 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(xs_read_bytes, ret);
+
+ xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+ return ret;
+}
+
+STATIC ssize_t
+xfs_file_splice_read(
+ struct file *infilp,
+ loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t count,
+ unsigned int flags)
+{
+ struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
+ int ioflags = 0;
+ ssize_t ret;
+
+ XFS_STATS_INC(xs_read_calls);
+
+ if (infilp->f_mode & FMODE_NOCMTIME)
+ ioflags |= XFS_IO_INVIS;
+
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return -EIO;
+
+ xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+
+ trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
+
+ ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
+ if (ret > 0)
+ XFS_STATS_ADD(xs_read_bytes, ret);
+
+ xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+ return ret;
+}
+
+/*
+ * 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);
+
+ /*
+ * 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);
+
+restart:
+ error = generic_write_checks(iocb, from);
+ if (error <= 0)
+ return error;
+
+ error = xfs_break_layouts(inode, iolock, true);
+ if (error)
+ return error;
+
+ /*
+ * 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 (*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);
+ 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.
+ */
+ return file_remove_suid(file);
+}
+
+/*
+ * xfs_file_dio_aio_write - handle direct IO writes
+ *
+ * Lock the inode appropriately to prepare for and issue a direct IO write.
+ * By separating it from the buffered write path we remove all the tricky to
+ * follow locking changes and looping.
+ *
+ * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
+ * until we're sure the bytes at the new EOF have been zeroed and/or the cached
+ * pages are flushed out.
+ *
+ * In most cases the direct IO writes will be done holding IOLOCK_SHARED
+ * allowing them to be done in parallel with reads and other direct IO writes.
+ * However, if the IO is not aligned to filesystem blocks, the direct IO layer
+ * needs to do sub-block zeroing and that requires serialisation against other
+ * direct IOs to the same block. In this case we need to serialise the
+ * submission of the unaligned IOs so that we don't get racing block zeroing in
+ * the dio layer. To avoid the problem with aio, we also need to wait for
+ * outstanding IOs to complete so that unwritten extent conversion is completed
+ * before we try to map the overlapping block. This is currently implemented by
+ * hitting it with a big hammer (i.e. inode_dio_wait()).
+ *
+ * Returns with locks held indicated by @iolock and errors indicated by
+ * negative return values.
+ */
+STATIC ssize_t
+xfs_file_dio_aio_write(
+ struct kiocb *iocb,
+ 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 ((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;
+
+ if (mapping->nrpages) {
+ ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
+ pos, end);
+ 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_range(VFS_I(ip)->i_mapping,
+ pos >> PAGE_CACHE_SHIFT,
+ end >> PAGE_CACHE_SHIFT);
+ 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. */
+ ASSERT(ret < 0 || ret == count);
+ 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(xs_write_calls);
+
+ if (ocount == 0)
+ return 0;
+
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return -EIO;
+
+ if (unlikely(iocb->ki_flags & IOCB_DIRECT))
+ 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(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);
+}
+
+STATIC int
+xfs_file_mmap(
+ struct file *filp,
+ struct vm_area_struct *vma)
+{
+ vma->vm_ops = &xfs_file_vm_ops;
+
+ file_accessed(filp);
+ return 0;
+}
+
+/*
+ * 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;
+}
+
+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;
+ loff_t uninitialized_var(offset);
+ xfs_fsize_t isize;
+ xfs_fileoff_t fsbno;
+ xfs_filblks_t end;
+ uint lock;
+ int error;
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -EIO;
+
+ lock = xfs_ilock_data_map_shared(ip);
+
+ isize = i_size_read(inode);
+ if (start >= isize) {
+ error = -ENXIO;
+ goto out_unlock;
+ }
+
+ /*
+ * 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);
+ end = XFS_B_TO_FSB(mp, isize);
+
+ for (;;) {
+ struct xfs_bmbt_irec map[2];
+ int nmap = 2;
+ unsigned int i;
+
+ error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
+ XFS_BMAPI_ENTIRE);
+ if (error)
+ goto out_unlock;
+
+ /* No extents at given offset, must be beyond EOF */
+ if (nmap == 0) {
+ error = -ENXIO;
+ goto out_unlock;
+ }
+
+ 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 = isize;
+ break;
+ }
+ /*
+ * If we were looking for data, it's nowhere to be found
+ */
+ ASSERT(whence == SEEK_DATA);
+ error = -ENXIO;
+ goto out_unlock;
+ }
+
+ 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 >= isize) {
+ if (whence == SEEK_HOLE) {
+ offset = isize;
+ break;
+ }
+ ASSERT(whence == SEEK_DATA);
+ error = -ENXIO;
+ goto out_unlock;
+ }
+ }
+
+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, isize);
+ 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)
+ * i_mmap_lock (XFS - truncate serialisation)
+ * page_lock (MM)
+ * i_lock (XFS - extent map serialisation)
+ */
+STATIC int
+xfs_filemap_fault(
+ struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host);
+ int error;
+
+ trace_xfs_filemap_fault(ip);
+
+ xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+ error = filemap_fault(vma, vmf);
+ xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+
+ return error;
+}
+
+/*
+ * 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 xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host);
+ int error;
+
+ trace_xfs_filemap_page_mkwrite(ip);
+
+ xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+ error = block_page_mkwrite(vma, vmf, xfs_get_blocks);
+ xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+
+ return error;
+}
+
+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,
+};
+
+static const struct vm_operations_struct xfs_file_vm_ops = {
+ .fault = xfs_filemap_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = xfs_filemap_page_mkwrite,
+};
Code Review / kvmfornfv.git / blobdiff