From: Joel Becker Date: Thu, 29 Mar 2007 01:27:07 +0000 (-0700) Subject: ocfs2: Wrap access of directory allocations with ip_alloc_sem. X-Git-Tag: v2.6.22-rc1~1033^2~6 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=ee19a77956cb65c5da54d85a5efefe50b39fa6e5;p=linux-2.6-omap-h63xx.git ocfs2: Wrap access of directory allocations with ip_alloc_sem. OCFS2_I(inode)->ip_alloc_sem is a read-write semaphore protecting local concurrent access of ocfs2 inodes. However, ocfs2 directories were not taking the semaphore while they accessed or modified the allocation tree. ocfs2_extend_dir() needs to take the semaphore in a write mode when it adds to the allocation. All other directory users get there via ocfs2_bread(), which takes the semaphore in read mode. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 67e6866a2a4..c441ef1f2ba 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -403,7 +403,7 @@ static int ocfs2_extend_dir(struct ocfs2_super *osb, struct buffer_head **new_de_bh) { int status = 0; - int credits, num_free_extents; + int credits, num_free_extents, drop_alloc_sem = 0; loff_t dir_i_size; struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data; struct ocfs2_alloc_context *data_ac = NULL; @@ -452,6 +452,9 @@ static int ocfs2_extend_dir(struct ocfs2_super *osb, credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS; } + down_write(&OCFS2_I(dir)->ip_alloc_sem); + drop_alloc_sem = 1; + handle = ocfs2_start_trans(osb, credits); if (IS_ERR(handle)) { status = PTR_ERR(handle); @@ -497,6 +500,8 @@ static int ocfs2_extend_dir(struct ocfs2_super *osb, *new_de_bh = new_bh; get_bh(*new_de_bh); bail: + if (drop_alloc_sem) + up_write(&OCFS2_I(dir)->ip_alloc_sem); if (handle) ocfs2_commit_trans(osb, handle); diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 21a605079c6..58ec54b6003 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -1106,8 +1106,10 @@ struct buffer_head *ocfs2_bread(struct inode *inode, return NULL; } + down_read(&OCFS2_I(inode)->ip_alloc_sem); tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL); + up_read(&OCFS2_I(inode)->ip_alloc_sem); if (tmperr < 0) { mlog_errno(tmperr); goto fail;