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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /fs/xfs/xfs_file.c
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'fs/xfs/xfs_file.c')
-rw-r--r--fs/xfs/xfs_file.c116
1 files changed, 89 insertions, 27 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index e78feb400..f5392ab2d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -242,19 +242,30 @@ xfs_file_fsync(
}
/*
- * All metadata updates are logged, which means that we just have
- * to flush the log up to the latest LSN that touched the inode.
+ * 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_fields & ~XFS_ILOG_TIMESTAMP))
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
lsn = ip->i_itemp->ili_last_lsn;
}
- xfs_iunlock(ip, XFS_ILOCK_SHARED);
- if (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
@@ -287,7 +298,7 @@ xfs_file_read_iter(
xfs_fsize_t n;
loff_t pos = iocb->ki_pos;
- XFS_STATS_INC(xs_read_calls);
+ XFS_STATS_INC(mp, xs_read_calls);
if (unlikely(iocb->ki_flags & IOCB_DIRECT))
ioflags |= XFS_IO_ISDIRECT;
@@ -365,7 +376,7 @@ xfs_file_read_iter(
ret = generic_file_read_iter(iocb, to);
if (ret > 0)
- XFS_STATS_ADD(xs_read_bytes, ret);
+ XFS_STATS_ADD(mp, xs_read_bytes, ret);
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
@@ -383,7 +394,7 @@ xfs_file_splice_read(
int ioflags = 0;
ssize_t ret;
- XFS_STATS_INC(xs_read_calls);
+ XFS_STATS_INC(ip->i_mount, xs_read_calls);
if (infilp->f_mode & FMODE_NOCMTIME)
ioflags |= XFS_IO_INVIS;
@@ -401,7 +412,7 @@ xfs_file_splice_read(
else
ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
if (ret > 0)
- XFS_STATS_ADD(xs_read_bytes, ret);
+ XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret);
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
@@ -482,6 +493,8 @@ xfs_zero_eof(
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.
*
@@ -574,6 +587,7 @@ xfs_file_aio_write_checks(
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);
@@ -611,12 +625,13 @@ restart:
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);
-
+ 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
@@ -626,6 +641,7 @@ restart:
* no-op.
*/
inode_dio_wait(inode);
+ drained_dio = true;
goto restart;
}
error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero);
@@ -867,7 +883,7 @@ xfs_file_write_iter(
ssize_t ret;
size_t ocount = iov_iter_count(from);
- XFS_STATS_INC(xs_write_calls);
+ XFS_STATS_INC(ip->i_mount, xs_write_calls);
if (ocount == 0)
return 0;
@@ -883,7 +899,7 @@ xfs_file_write_iter(
if (ret > 0) {
ssize_t err;
- XFS_STATS_ADD(xs_write_bytes, ret);
+ 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);
@@ -1477,7 +1493,7 @@ xfs_file_llseek(
*
* mmap_sem (MM)
* sb_start_pagefault(vfs, freeze)
- * i_mmap_lock (XFS - truncate serialisation)
+ * i_mmaplock (XFS - truncate serialisation)
* page_lock (MM)
* i_lock (XFS - extent map serialisation)
*/
@@ -1503,10 +1519,9 @@ xfs_filemap_page_mkwrite(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_direct,
- xfs_end_io_dax_write);
+ 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(vma, vmf, xfs_get_blocks);
ret = block_page_mkwrite_return(ret);
}
@@ -1538,7 +1553,7 @@ xfs_filemap_fault(
* 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_direct, NULL);
+ 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);
@@ -1546,6 +1561,13 @@ xfs_filemap_fault(
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,
@@ -1562,15 +1584,54 @@ xfs_filemap_pmd_fault(
trace_xfs_filemap_pmd_fault(ip);
- sb_start_pagefault(inode->i_sb);
- file_update_time(vma->vm_file);
+ 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_direct,
- xfs_end_io_dax_write);
+ ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault,
+ NULL);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
+ 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 open-code dax_pfn_mkwrite()
+ * here and 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;
+ xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+ sb_end_pagefault(inode->i_sb);
return ret;
+
}
static const struct vm_operations_struct xfs_file_vm_ops = {
@@ -1578,6 +1639,7 @@ static const struct vm_operations_struct xfs_file_vm_ops = {
.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