[PATCH 01/11] xfs: remove xfs_itruncate_data

Christoph Hellwig
2011-12-08T15:59:20Z

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This wrapper isn't overly useful, not to say rather confusing.

Around the call to xfs_itruncate_extents it does:

- add tracing
- add a few asserts in debug builds
- conditionally update the inode size in two places
- log the inode

Both the tracing and the inode logging can be moved to xfs_itruncate_extents
as they are useful for the attribute fork as well - in fact the attr code
already does an equivalent xfs_trans_log_inode call just after calling
xfs_itruncate_extents. The conditional size updates are a mess, and there
was no reason to do them in two places anyway, as the first one was
conditional on the inode having extents - but without extents we
xfs_itruncate_extents would be a no-op and the placement wouldn't matter
anyway. Instead move the size assignments and the asserts that make sense
to the callers that want it.

As a side effect of this clean up xfs_setattr_size by introducing variables
for the old and new inode size, and moving the size updates into a common
place.

Signed-off-by: Christoph Hellwig <hch@lst.de>

---
fs/xfs/xfs_attr.c | 4 -
fs/xfs/xfs_inode.c | 124 +++--------------------------------------------
fs/xfs/xfs_inode.h | 2
fs/xfs/xfs_iops.c | 47 +++++++++++------
fs/xfs/xfs_qm_syscalls.c | 9 +++
fs/xfs/xfs_trace.h | 4 -
fs/xfs/xfs_vnodeops.c | 17 +++++-
7 files changed, 65 insertions(+), 142 deletions(-)

Index: xfs/fs/xfs/xfs_attr.c
===================================================================
--- xfs.orig/fs/xfs/xfs_attr.c 2011-11-30 12:58:07.820044461 +0100
+++ xfs/fs/xfs/xfs_attr.c 2011-11-30 12:58:51.519807719 +0100
@@ -827,10 +827,6 @@ xfs_attr_inactive(xfs_inode_t *dp)
if (error)
goto out;

- /*
- * Commit the last in the sequence of transactions.
- */
- xfs_trans_log_inode(trans, dp, XFS_ILOG_CORE);
error = xfs_trans_commit(trans, XFS_TRANS_RELEASE_LOG_RES);
xfs_iunlock(dp, XFS_ILOCK_EXCL);

Index: xfs/fs/xfs/xfs_inode.c
===================================================================
--- xfs.orig/fs/xfs/xfs_inode.c 2011-11-30 12:58:07.830044408 +0100
+++ xfs/fs/xfs/xfs_inode.c 2011-11-30 12:58:51.519807719 +0100
@@ -1166,52 +1166,6 @@ xfs_ialloc(
}

/*
- * Check to make sure that there are no blocks allocated to the
- * file beyond the size of the file. We don't check this for
- * files with fixed size extents or real time extents, but we
- * at least do it for regular files.
- */
-#ifdef DEBUG
-STATIC void
-xfs_isize_check(
- struct xfs_inode *ip,
- xfs_fsize_t isize)
-{
- struct xfs_mount *mp = ip->i_mount;
- xfs_fileoff_t map_first;
- int nimaps;
- xfs_bmbt_irec_t imaps[2];
- int error;
-
- if (!S_ISREG(ip->i_d.di_mode))
- return;
-
- if (XFS_IS_REALTIME_INODE(ip))
- return;
-
- if (ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE)
- return;
-
- nimaps = 2;
- map_first = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
- /*
- * The filesystem could be shutting down, so bmapi may return
- * an error.
- */
- error = xfs_bmapi_read(ip, map_first,
- (XFS_B_TO_FSB(mp,
- (xfs_ufsize_t)XFS_MAXIOFFSET(mp)) - map_first),
- imaps, &nimaps, XFS_BMAPI_ENTIRE);
- if (error)
- return;
- ASSERT(nimaps == 1);
- ASSERT(imaps[0].br_startblock == HOLESTARTBLOCK);
-}
-#else /* DEBUG */
-#define xfs_isize_check(ip, isize)
-#endif /* DEBUG */
-
-/*
* Free up the underlying blocks past new_size. The new size must be smaller
* than the current size. This routine can be used both for the attribute and
* data fork, and does not modify the inode size, which is left to the caller.
@@ -1258,6 +1212,8 @@ xfs_itruncate_extents(
ASSERT(ip->i_itemp->ili_lock_flags == 0);
ASSERT(!XFS_NOT_DQATTACHED(mp, ip));

+ trace_xfs_itruncate_extents_start(ip, new_size);
+
/*
* Since it is possible for space to become allocated beyond
* the end of the file (in a crash where the space is allocated
@@ -1325,6 +1281,14 @@ xfs_itruncate_extents(
goto out;
}

+ /*
+ * Always re-log the inode so that our permanent transaction can keep
+ * on rolling it forward in the log.
+ */
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ trace_xfs_itruncate_extents_end(ip, new_size);
+
out:
*tpp = tp;
return error;
@@ -1338,74 +1302,6 @@ out_bmap_cancel:
goto out;
}

-int
-xfs_itruncate_data(
- struct xfs_trans **tpp,
- struct xfs_inode *ip,
- xfs_fsize_t new_size)
-{
- int error;
-
- trace_xfs_itruncate_data_start(ip, new_size);
-
- /*
- * The first thing we do is set the size to new_size permanently on
- * disk. This way we don't have to worry about anyone ever being able
- * to look at the data being freed even in the face of a crash.
- * What we're getting around here is the case where we free a block, it
- * is allocated to another file, it is written to, and then we crash.
- * If the new data gets written to the file but the log buffers
- * containing the free and reallocation don't, then we'd end up with
- * garbage in the blocks being freed. As long as we make the new_size
- * permanent before actually freeing any blocks it doesn't matter if
- * they get written to.
- */
- if (ip->i_d.di_nextents > 0) {
- /*
- * If we are not changing the file size then do not update
- * the on-disk file size - we may be called from
- * xfs_inactive_free_eofblocks(). If we update the on-disk
- * file size and then the system crashes before the contents
- * of the file are flushed to disk then the files may be
- * full of holes (ie NULL files bug).
- */
- if (ip->i_size != new_size) {
- ip->i_d.di_size = new_size;
- ip->i_size = new_size;
- xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE);
- }
- }
-
- error = xfs_itruncate_extents(tpp, ip, XFS_DATA_FORK, new_size);
- if (error)
- return error;
-
- /*
- * If we are not changing the file size then do not update the on-disk
- * file size - we may be called from xfs_inactive_free_eofblocks().
- * If we update the on-disk file size and then the system crashes
- * before the contents of the file are flushed to disk then the files
- * may be full of holes (ie NULL files bug).
- */
- xfs_isize_check(ip, new_size);
- if (ip->i_size != new_size) {
- ip->i_d.di_size = new_size;
- ip->i_size = new_size;
- }
-
- ASSERT(new_size != 0 || ip->i_delayed_blks == 0);
- ASSERT(new_size != 0 || ip->i_d.di_nextents == 0);
-
- /*
- * Always re-log the inode so that our permanent transaction can keep
- * on rolling it forward in the log.
- */
- xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE);
-
- trace_xfs_itruncate_data_end(ip, new_size);
- return 0;
-}
-
/*
* This is called when the inode's link count goes to 0.
* We place the on-disk inode on a list in the AGI. It
Index: xfs/fs/xfs/xfs_inode.h
===================================================================
--- xfs.orig/fs/xfs/xfs_inode.h 2011-11-30 12:58:08.843372251 +0100
+++ xfs/fs/xfs/xfs_inode.h 2011-11-30 12:58:51.523141034 +0100
@@ -491,8 +491,6 @@ int xfs_ifree(struct xfs_trans *, xfs_i
struct xfs_bmap_free *);
int xfs_itruncate_extents(struct xfs_trans **, struct xfs_inode *,
int, xfs_fsize_t);
-int xfs_itruncate_data(struct xfs_trans **, struct xfs_inode *,
- xfs_fsize_t);
int xfs_iunlink(struct xfs_trans *, xfs_inode_t *);

void xfs_iext_realloc(xfs_inode_t *, int, int);
Index: xfs/fs/xfs/xfs_iops.c
===================================================================
--- xfs.orig/fs/xfs/xfs_iops.c 2011-11-30 12:58:07.856710929 +0100
+++ xfs/fs/xfs/xfs_iops.c 2011-11-30 12:58:51.523141034 +0100
@@ -750,6 +750,7 @@ xfs_setattr_size(
struct xfs_mount *mp = ip->i_mount;
struct inode *inode = VFS_I(ip);
int mask = iattr->ia_valid;
+ xfs_off_t oldsize, newsize;
struct xfs_trans *tp;
int error;
uint lock_flags;
@@ -777,11 +778,13 @@ xfs_setattr_size(
lock_flags |= XFS_IOLOCK_EXCL;
xfs_ilock(ip, lock_flags);

+ oldsize = ip->i_size;
+ newsize = iattr->ia_size;
+
/*
* Short circuit the truncate case for zero length files.
*/
- if (iattr->ia_size == 0 &&
- ip->i_size == 0 && ip->i_d.di_nextents == 0) {
+ if (newsize == 0 && oldsize == 0 && ip->i_d.di_nextents == 0) {
if (!(mask & (ATTR_CTIME|ATTR_MTIME)))
goto out_unlock;

@@ -807,14 +810,14 @@ xfs_setattr_size(
* the inode to the transaction, because the inode cannot be unlocked
* once it is a part of the transaction.
*/
- if (iattr->ia_size > ip->i_size) {
+ if (newsize > oldsize) {
/*
* Do the first part of growing a file: zero any data in the
* last block that is beyond the old EOF. We need to do this
* before the inode is joined to the transaction to modify
* i_size.
*/
- error = xfs_zero_eof(ip, iattr->ia_size, ip->i_size);
+ error = xfs_zero_eof(ip, newsize, oldsize);
if (error)
goto out_unlock;
}
@@ -833,8 +836,8 @@ xfs_setattr_size(
* here and prevents waiting for other data not within the range we
* care about here.
*/
- if (ip->i_size != ip->i_d.di_size && iattr->ia_size > ip->i_d.di_size) {
- error = xfs_flush_pages(ip, ip->i_d.di_size, iattr->ia_size, 0,
+ if (oldsize != ip->i_d.di_size && newsize > ip->i_d.di_size) {
+ error = xfs_flush_pages(ip, ip->i_d.di_size, newsize, 0,
FI_NONE);
if (error)
goto out_unlock;
@@ -845,8 +848,7 @@ xfs_setattr_size(
*/
inode_dio_wait(inode);

- error = -block_truncate_page(inode->i_mapping, iattr->ia_size,
- xfs_get_blocks);
+ error = -block_truncate_page(inode->i_mapping, newsize, xfs_get_blocks);
if (error)
goto out_unlock;

@@ -857,7 +859,7 @@ xfs_setattr_size(
if (error)
goto out_trans_cancel;

- truncate_setsize(inode, iattr->ia_size);
+ truncate_setsize(inode, newsize);

commit_flags = XFS_TRANS_RELEASE_LOG_RES;
lock_flags |= XFS_ILOCK_EXCL;
@@ -876,19 +878,30 @@ xfs_setattr_size(
* these flags set. For all other operations the VFS set these flags
* explicitly if it wants a timestamp update.
*/
- if (iattr->ia_size != ip->i_size &&
- (!(mask & (ATTR_CTIME | ATTR_MTIME)))) {
+ if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME)))) {
iattr->ia_ctime = iattr->ia_mtime =
current_fs_time(inode->i_sb);
mask |= ATTR_CTIME | ATTR_MTIME;
}

- if (iattr->ia_size > ip->i_size) {
- ip->i_d.di_size = iattr->ia_size;
- ip->i_size = iattr->ia_size;
- } else if (iattr->ia_size <= ip->i_size ||
- (iattr->ia_size == 0 && ip->i_d.di_nextents)) {
- error = xfs_itruncate_data(&tp, ip, iattr->ia_size);
+ /*
+ * The first thing we do is set the size to new_size permanently on
+ * disk. This way we don't have to worry about anyone ever being able
+ * to look at the data being freed even in the face of a crash.
+ * What we're getting around here is the case where we free a block, it
+ * is allocated to another file, it is written to, and then we crash.
+ * If the new data gets written to the file but the log buffers
+ * containing the free and reallocation don't, then we'd end up with
+ * garbage in the blocks being freed. As long as we make the new size
+ * permanent before actually freeing any blocks it doesn't matter if
+ * they get written to.
+ */
+ ip->i_d.di_size = newsize;
+ ip->i_size = newsize;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ if (newsize <= oldsize) {
+ error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
if (error)
goto out_trans_abort;

Index: xfs/fs/xfs/xfs_qm_syscalls.c
===================================================================
--- xfs.orig/fs/xfs/xfs_qm_syscalls.c 2011-11-30 12:58:07.866710876 +0100
+++ xfs/fs/xfs/xfs_qm_syscalls.c 2011-11-30 12:58:51.523141034 +0100
@@ -31,6 +31,7 @@
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
+#include "xfs_inode_item.h"
#include "xfs_itable.h"
#include "xfs_bmap.h"
#include "xfs_rtalloc.h"
@@ -263,13 +264,19 @@ xfs_qm_scall_trunc_qfile(
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);

- error = xfs_itruncate_data(&tp, ip, 0);
+ ip->i_d.di_size = 0;
+ ip->i_size = 0;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
if (error) {
xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
XFS_TRANS_ABORT);
goto out_unlock;
}

+ ASSERT(ip->i_d.di_nextents == 0);
+
xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);

Index: xfs/fs/xfs/xfs_trace.h
===================================================================
--- xfs.orig/fs/xfs/xfs_trace.h 2011-11-30 12:58:07.876710822 +0100
+++ xfs/fs/xfs/xfs_trace.h 2011-11-30 12:58:51.523141034 +0100
@@ -1090,8 +1090,8 @@ DECLARE_EVENT_CLASS(xfs_itrunc_class,
DEFINE_EVENT(xfs_itrunc_class, name, \
TP_PROTO(struct xfs_inode *ip, xfs_fsize_t new_size), \
TP_ARGS(ip, new_size))
-DEFINE_ITRUNC_EVENT(xfs_itruncate_data_start);
-DEFINE_ITRUNC_EVENT(xfs_itruncate_data_end);
+DEFINE_ITRUNC_EVENT(xfs_itruncate_extents_start);
+DEFINE_ITRUNC_EVENT(xfs_itruncate_extents_end);

TRACE_EVENT(xfs_pagecache_inval,
TP_PROTO(struct xfs_inode *ip, xfs_off_t start, xfs_off_t finish),
Index: xfs/fs/xfs/xfs_vnodeops.c
===================================================================
--- xfs.orig/fs/xfs/xfs_vnodeops.c 2011-11-30 12:58:07.893377397 +0100
+++ xfs/fs/xfs/xfs_vnodeops.c 2011-11-30 12:58:51.526474350 +0100
@@ -226,7 +226,14 @@ xfs_free_eofblocks(
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);

- error = xfs_itruncate_data(&tp, ip, ip->i_size);
+ /*
+ * Do not update the on-disk file size. If we update the
+ * on-disk file size and then the system crashes before the
+ * contents of the file are flushed to disk then the files
+ * may be full of holes (ie NULL files bug).
+ */
+ error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK,
+ ip->i_size);
if (error) {
/*
* If we get an error at this point we simply don't
@@ -670,13 +677,19 @@ xfs_inactive(
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0);

- error = xfs_itruncate_data(&tp, ip, 0);
+ ip->i_d.di_size = 0;
+ ip->i_size = 0;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
if (error) {
xfs_trans_cancel(tp,
XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
xfs_iunlock(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
return VN_INACTIVE_CACHE;
}
+
+ ASSERT(ip->i_d.di_nextents == 0);
} else if (S_ISLNK(ip->i_d.di_mode)) {

/*