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Diffstat (limited to 'fs/xfs/xfs_file.c')
-rw-r--r--fs/xfs/xfs_file.c168
1 files changed, 125 insertions, 43 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7f7b42469ea7..753ed9b5c70b 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -124,6 +124,35 @@ xfs_iozero(
return (-status);
}
+/*
+ * 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,
@@ -137,6 +166,7 @@ xfs_file_fsync(
struct xfs_trans *tp;
int error = 0;
int log_flushed = 0;
+ xfs_lsn_t lsn = 0;
trace_xfs_file_fsync(ip);
@@ -149,10 +179,6 @@ xfs_file_fsync(
xfs_iflags_clear(ip, XFS_ITRUNCATED);
- xfs_ilock(ip, XFS_IOLOCK_SHARED);
- xfs_ioend_wait(ip);
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-
if (mp->m_flags & XFS_MOUNT_BARRIER) {
/*
* If we have an RT and/or log subvolume we need to make sure
@@ -216,11 +242,11 @@ xfs_file_fsync(
* transaction. So we play it safe and fire off the
* transaction anyway.
*/
- xfs_trans_ijoin(tp, ip);
+ xfs_trans_ijoin(tp, ip, 0);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
- xfs_trans_set_sync(tp);
- error = _xfs_trans_commit(tp, 0, &log_flushed);
+ error = xfs_trans_commit(tp, 0);
+ lsn = ip->i_itemp->ili_last_lsn;
xfs_iunlock(ip, XFS_ILOCK_EXCL);
} else {
/*
@@ -231,14 +257,14 @@ xfs_file_fsync(
* disk yet, the inode will be still be pinned. If it is,
* force the log.
*/
- if (xfs_ipincount(ip)) {
- error = _xfs_log_force_lsn(mp,
- ip->i_itemp->ili_last_lsn,
- XFS_LOG_SYNC, &log_flushed);
- }
+ if (xfs_ipincount(ip))
+ lsn = ip->i_itemp->ili_last_lsn;
xfs_iunlock(ip, XFS_ILOCK_SHARED);
}
+ if (!error && 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.
@@ -317,7 +343,19 @@ xfs_file_aio_read(
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
- if (unlikely(ioflags & IO_ISDIRECT)) {
+ /*
+ * 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 & 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) {
@@ -330,8 +368,7 @@ xfs_file_aio_read(
}
}
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
- } else
- xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+ }
trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags);
@@ -407,11 +444,13 @@ xfs_aio_write_isize_update(
*/
STATIC void
xfs_aio_write_newsize_update(
- struct xfs_inode *ip)
+ struct xfs_inode *ip,
+ xfs_fsize_t new_size)
{
- if (ip->i_new_size) {
+ if (new_size == ip->i_new_size) {
xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
- ip->i_new_size = 0;
+ if (new_size == ip->i_new_size)
+ ip->i_new_size = 0;
if (ip->i_d.di_size > ip->i_size)
ip->i_d.di_size = ip->i_size;
xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
@@ -462,7 +501,7 @@ xfs_file_splice_write(
ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
xfs_aio_write_isize_update(inode, ppos, ret);
- xfs_aio_write_newsize_update(ip);
+ xfs_aio_write_newsize_update(ip, new_size);
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
}
@@ -500,11 +539,9 @@ xfs_zero_last_block(
last_fsb = XFS_B_TO_FSBT(mp, isize);
nimaps = 1;
- error = xfs_bmapi(NULL, ip, last_fsb, 1, 0, NULL, 0, &imap,
- &nimaps, NULL);
- if (error) {
+ error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
+ if (error)
return error;
- }
ASSERT(nimaps > 0);
/*
* If the block underlying isize is just a hole, then there
@@ -595,8 +632,8 @@ xfs_zero_eof(
while (start_zero_fsb <= end_zero_fsb) {
nimaps = 1;
zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
- error = xfs_bmapi(NULL, ip, start_zero_fsb, zero_count_fsb,
- 0, NULL, 0, &imap, &nimaps, NULL);
+ error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
+ &imap, &nimaps, 0);
if (error) {
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
return error;
@@ -659,6 +696,7 @@ xfs_file_aio_write_checks(
struct file *file,
loff_t *pos,
size_t *count,
+ xfs_fsize_t *new_sizep,
int *iolock)
{
struct inode *inode = file->f_mapping->host;
@@ -666,6 +704,9 @@ xfs_file_aio_write_checks(
xfs_fsize_t new_size;
int error = 0;
+ xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
+ *new_sizep = 0;
+restart:
error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
if (error) {
xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
@@ -673,20 +714,41 @@ xfs_file_aio_write_checks(
return error;
}
- new_size = *pos + *count;
- if (new_size > ip->i_size)
- ip->i_new_size = new_size;
-
if (likely(!(file->f_mode & FMODE_NOCMTIME)))
file_update_time(file);
/*
* 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.
+ * write. There is no need to issue zeroing if another in-flght IO ends
+ * at or before this one If zeronig is needed and we are currently
+ * holding the iolock shared, we need to update it to exclusive which
+ * involves dropping all locks and relocking to maintain correct locking
+ * order. If we do this, restart the function to ensure all checks and
+ * values are still valid.
*/
- if (*pos > ip->i_size)
+ if ((ip->i_new_size && *pos > ip->i_new_size) ||
+ (!ip->i_new_size && *pos > ip->i_size)) {
+ if (*iolock == XFS_IOLOCK_SHARED) {
+ xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
+ *iolock = XFS_IOLOCK_EXCL;
+ xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
+ goto restart;
+ }
error = -xfs_zero_eof(ip, *pos, ip->i_size);
+ }
+
+ /*
+ * If this IO extends beyond EOF, we may need to update ip->i_new_size.
+ * We have already zeroed space beyond EOF (if necessary). Only update
+ * ip->i_new_size if this IO ends beyond any other in-flight writes.
+ */
+ new_size = *pos + *count;
+ if (new_size > ip->i_size) {
+ if (new_size > ip->i_new_size)
+ ip->i_new_size = new_size;
+ *new_sizep = new_size;
+ }
xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
@@ -721,7 +783,7 @@ xfs_file_aio_write_checks(
* 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. xfs_ioend_wait()).
+ * 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.
@@ -733,6 +795,7 @@ xfs_file_dio_aio_write(
unsigned long nr_segs,
loff_t pos,
size_t ocount,
+ xfs_fsize_t *new_size,
int *iolock)
{
struct file *file = iocb->ki_filp;
@@ -753,18 +816,35 @@ xfs_file_dio_aio_write(
if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
unaligned_io = 1;
- if (unaligned_io || mapping->nrpages || pos > ip->i_size)
+ /*
+ * 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, XFS_ILOCK_EXCL | *iolock);
+ xfs_rw_ilock(ip, *iolock);
- ret = xfs_file_aio_write_checks(file, &pos, &count, 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(file, &pos, &count, new_size, iolock);
if (ret)
return ret;
if (mapping->nrpages) {
- WARN_ON(*iolock != XFS_IOLOCK_EXCL);
ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1,
FI_REMAPF_LOCKED);
if (ret)
@@ -776,7 +856,7 @@ xfs_file_dio_aio_write(
* otherwise demote the lock if we had to flush cached pages
*/
if (unaligned_io)
- xfs_ioend_wait(ip);
+ inode_dio_wait(inode);
else if (*iolock == XFS_IOLOCK_EXCL) {
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
*iolock = XFS_IOLOCK_SHARED;
@@ -798,6 +878,7 @@ xfs_file_buffered_aio_write(
unsigned long nr_segs,
loff_t pos,
size_t ocount,
+ xfs_fsize_t *new_size,
int *iolock)
{
struct file *file = iocb->ki_filp;
@@ -809,9 +890,9 @@ xfs_file_buffered_aio_write(
size_t count = ocount;
*iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
+ xfs_rw_ilock(ip, *iolock);
- ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
+ ret = xfs_file_aio_write_checks(file, &pos, &count, new_size, iolock);
if (ret)
return ret;
@@ -851,6 +932,7 @@ xfs_file_aio_write(
ssize_t ret;
int iolock;
size_t ocount = 0;
+ xfs_fsize_t new_size = 0;
XFS_STATS_INC(xs_write_calls);
@@ -870,10 +952,10 @@ xfs_file_aio_write(
if (unlikely(file->f_flags & O_DIRECT))
ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos,
- ocount, &iolock);
+ ocount, &new_size, &iolock);
else
ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
- ocount, &iolock);
+ ocount, &new_size, &iolock);
xfs_aio_write_isize_update(inode, &iocb->ki_pos, ret);
@@ -894,7 +976,7 @@ xfs_file_aio_write(
}
out_unlock:
- xfs_aio_write_newsize_update(ip);
+ xfs_aio_write_newsize_update(ip, new_size);
xfs_rw_iunlock(ip, iolock);
return ret;
}
@@ -1087,7 +1169,7 @@ const struct file_operations xfs_dir_file_operations = {
#ifdef CONFIG_COMPAT
.compat_ioctl = xfs_file_compat_ioctl,
#endif
- .fsync = xfs_file_fsync,
+ .fsync = xfs_dir_fsync,
};
static const struct vm_operations_struct xfs_file_vm_ops = {