From 970e4936d7d15f35d00fd15a14f5343ba78b2fc8 Mon Sep 17 00:00:00 2001 From: Joel Becker Date: Thu, 13 Nov 2008 14:49:19 -0800 Subject: ocfs2: Validate metadata only when it's read from disk. Add an optional validation hook to ocfs2_read_blocks(). Now the validation function is only called when a block was actually read off of disk. It is not called when the buffer was in cache. We add a buffer state bit BH_NeedsValidate to flag these buffers. It must always be one higher than the last JBD2 buffer state bit. The dinode, dirblock, extent_block, and xattr_block validators are lifted to this scheme directly. The group_descriptor validator needs to be split into two pieces. The first part only needs the gd buffer and is passed to ocfs2_read_block(). The second part requires the dinode as well, and is called every time. It's only 3 compares, so it's tiny. This also allows us to clean up the non-fatal gd check used by resize.c. It now has no magic argument. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- fs/ocfs2/buffer_head_io.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'fs/ocfs2/buffer_head_io.c') diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c index 3a178ec48d7..0e9eed0c223 100644 --- a/fs/ocfs2/buffer_head_io.c +++ b/fs/ocfs2/buffer_head_io.c @@ -39,6 +39,19 @@ #include "buffer_head_io.h" +/* + * Bits on bh->b_state used by ocfs2. + * + * These MUST be after the JBD2 bits. Currently BH_Unshadow is the last + * JBD2 bit. + */ +enum ocfs2_state_bits { + BH_NeedsValidate = BH_Unshadow + 1, +}; + +/* Expand the magic b_state functions */ +BUFFER_FNS(NeedsValidate, needs_validate); + int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh, struct inode *inode) { @@ -166,7 +179,9 @@ bail: } int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, - struct buffer_head *bhs[], int flags) + struct buffer_head *bhs[], int flags, + int (*validate)(struct super_block *sb, + struct buffer_head *bh)) { int status = 0; int i, ignore_cache = 0; @@ -298,6 +313,8 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, clear_buffer_uptodate(bh); get_bh(bh); /* for end_buffer_read_sync() */ + if (validate) + set_buffer_needs_validate(bh); bh->b_end_io = end_buffer_read_sync; submit_bh(READ, bh); continue; @@ -328,6 +345,20 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, bhs[i] = NULL; continue; } + + if (buffer_needs_validate(bh)) { + /* We never set NeedsValidate if the + * buffer was held by the journal, so + * that better not have changed */ + BUG_ON(buffer_jbd(bh)); + clear_buffer_needs_validate(bh); + status = validate(inode->i_sb, bh); + if (status) { + put_bh(bh); + bhs[i] = NULL; + continue; + } + } } /* Always set the buffer in the cache, even if it was -- cgit v1.2.3