From 15c6fd9786dfaab43547bf60df6fa63170fb64fc Mon Sep 17 00:00:00 2001 From: "npiggin@suse.de" Date: Thu, 27 May 2010 01:05:34 +1000 Subject: kill spurious reference to vmtruncate Lots of filesystems calls vmtruncate despite not implementing the old ->truncate method. Switch them to use simple_setsize and add some comments about the truncate code where it seems fitting. Signed-off-by: Christoph Hellwig Signed-off-by: Nick Piggin Signed-off-by: Al Viro --- fs/ubifs/file.c | 13 ++++++++----- fs/ubifs/ubifs.h | 2 +- 2 files changed, 9 insertions(+), 6 deletions(-) (limited to 'fs/ubifs') diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index c726da6..12f445c 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -967,12 +967,15 @@ static int do_writepage(struct page *page, int len) * the page locked, and it locks @ui_mutex. However, write-back does take inode * @i_mutex, which means other VFS operations may be run on this inode at the * same time. And the problematic one is truncation to smaller size, from where - * we have to call 'vmtruncate()', which first changes @inode->i_size, then + * we have to call 'simple_setsize()', which first changes @inode->i_size, then * drops the truncated pages. And while dropping the pages, it takes the page - * lock. This means that 'do_truncation()' cannot call 'vmtruncate()' with + * lock. This means that 'do_truncation()' cannot call 'simple_setsize()' with * @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'. This * means that @inode->i_size is changed while @ui_mutex is unlocked. * + * XXX: with the new truncate the above is not true anymore, the simple_setsize + * calls can be replaced with the individual components. + * * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond * inode size. How do we do this if @inode->i_size may became smaller while we * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the @@ -1125,7 +1128,7 @@ static int do_truncation(struct ubifs_info *c, struct inode *inode, budgeted = 0; } - err = vmtruncate(inode, new_size); + err = simple_setsize(inode, new_size); if (err) goto out_budg; @@ -1214,7 +1217,7 @@ static int do_setattr(struct ubifs_info *c, struct inode *inode, if (attr->ia_valid & ATTR_SIZE) { dbg_gen("size %lld -> %lld", inode->i_size, new_size); - err = vmtruncate(inode, new_size); + err = simple_setsize(inode, new_size); if (err) goto out; } @@ -1223,7 +1226,7 @@ static int do_setattr(struct ubifs_info *c, struct inode *inode, if (attr->ia_valid & ATTR_SIZE) { /* Truncation changes inode [mc]time */ inode->i_mtime = inode->i_ctime = ubifs_current_time(inode); - /* 'vmtruncate()' changed @i_size, update @ui_size */ + /* 'simple_setsize()' changed @i_size, update @ui_size */ ui->ui_size = inode->i_size; } diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index b090453..2eef553 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -379,7 +379,7 @@ struct ubifs_gced_idx_leb { * The @ui_size is a "shadow" variable for @inode->i_size and UBIFS uses * @ui_size instead of @inode->i_size. The reason for this is that UBIFS cannot * make sure @inode->i_size is always changed under @ui_mutex, because it - * cannot call 'vmtruncate()' with @ui_mutex locked, because it would deadlock + * cannot call 'simple_setsize()' with @ui_mutex locked, because it would deadlock * with 'ubifs_writepage()' (see file.c). All the other inode fields are * changed under @ui_mutex, so they do not need "shadow" fields. Note, one * could consider to rework locking and base it on "shadow" fields. -- cgit v1.1