From 33a266dda9fbbe72dd978a451a8ee33c59da5e9c Mon Sep 17 00:00:00 2001 From: David Chinner Date: Mon, 12 Feb 2007 00:51:41 -0800 Subject: [PATCH] Make BH_Unwritten a first class bufferhead flag V2 Currently, XFS uses BH_PrivateStart for flagging unwritten extent state in a bufferhead. Recently, I found the long standing mmap/unwritten extent conversion bug, and it was to do with partial page invalidation not clearing the unwritten flag from bufferheads attached to the page but beyond EOF. See here for a full explaination: http://oss.sgi.com/archives/xfs/2006-12/msg00196.html The solution I have checked into the XFS dev tree involves duplicating code from block_invalidatepage to clear the unwritten flag from the bufferhead(s), and then calling block_invalidatepage() to do the rest. Christoph suggested that this would be better solved by pushing the unwritten flag into the common buffer head flags and just adding the call to discard_buffer(): http://oss.sgi.com/archives/xfs/2006-12/msg00239.html The following patch makes BH_Unwritten a first class citizen. Signed-off-by: Dave Chinner Acked-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/buffer_head.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/buffer_head.h') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 5d9fb0e94156..ffbdb6621f52 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -34,6 +34,7 @@ enum bh_state_bits { BH_Write_EIO, /* I/O error on write */ BH_Ordered, /* ordered write */ BH_Eopnotsupp, /* operation not supported (barrier) */ + BH_Unwritten, /* Buffer is allocated on disk but not written */ BH_PrivateStart,/* not a state bit, but the first bit available * for private allocation by other entities @@ -126,6 +127,7 @@ BUFFER_FNS(Boundary, boundary) BUFFER_FNS(Write_EIO, write_io_error) BUFFER_FNS(Ordered, ordered) BUFFER_FNS(Eopnotsupp, eopnotsupp) +BUFFER_FNS(Unwritten, unwritten) #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK) #define touch_buffer(bh) mark_page_accessed(bh->b_page) -- cgit v1.2.3 From 3991d3bd1506391d8feec209b1d22ccb1c03a0bf Mon Sep 17 00:00:00 2001 From: Tomasz Kvarsin Date: Mon, 12 Feb 2007 00:52:14 -0800 Subject: [PATCH] warning fix: unsigned->signed While compiling my code with -Wconversion using gcc-trunk, I always get a bunch of warrning from headers, here is fix for them: __getblk is alawys called with unsigned argument, but it takes signed, the same story with __bread,__breadahead and so on. Signed-off-by: Tomasz Kvarsin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/buffer.c | 12 ++++++------ include/linux/buffer_head.h | 10 ++++++---- 2 files changed, 12 insertions(+), 10 deletions(-) (limited to 'include/linux/buffer_head.h') diff --git a/fs/buffer.c b/fs/buffer.c index a4b824234fb9..f99c509697cd 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1283,11 +1283,11 @@ static void bh_lru_install(struct buffer_head *bh) * Look up the bh in this cpu's LRU. If it's there, move it to the head. */ static struct buffer_head * -lookup_bh_lru(struct block_device *bdev, sector_t block, int size) +lookup_bh_lru(struct block_device *bdev, sector_t block, unsigned size) { struct buffer_head *ret = NULL; struct bh_lru *lru; - int i; + unsigned int i; check_irqs_on(); bh_lru_lock(); @@ -1319,7 +1319,7 @@ lookup_bh_lru(struct block_device *bdev, sector_t block, int size) * NULL */ struct buffer_head * -__find_get_block(struct block_device *bdev, sector_t block, int size) +__find_get_block(struct block_device *bdev, sector_t block, unsigned size) { struct buffer_head *bh = lookup_bh_lru(bdev, block, size); @@ -1347,7 +1347,7 @@ EXPORT_SYMBOL(__find_get_block); * attempt is failing. FIXME, perhaps? */ struct buffer_head * -__getblk(struct block_device *bdev, sector_t block, int size) +__getblk(struct block_device *bdev, sector_t block, unsigned size) { struct buffer_head *bh = __find_get_block(bdev, block, size); @@ -1361,7 +1361,7 @@ EXPORT_SYMBOL(__getblk); /* * Do async read-ahead on a buffer.. */ -void __breadahead(struct block_device *bdev, sector_t block, int size) +void __breadahead(struct block_device *bdev, sector_t block, unsigned size) { struct buffer_head *bh = __getblk(bdev, block, size); if (likely(bh)) { @@ -1381,7 +1381,7 @@ EXPORT_SYMBOL(__breadahead); * It returns NULL if the block was unreadable. */ struct buffer_head * -__bread(struct block_device *bdev, sector_t block, int size) +__bread(struct block_device *bdev, sector_t block, unsigned size) { struct buffer_head *bh = __getblk(bdev, block, size); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index ffbdb6621f52..dd27b1c7227f 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -174,12 +174,14 @@ struct super_block *freeze_bdev(struct block_device *); void thaw_bdev(struct block_device *, struct super_block *); int fsync_super(struct super_block *); int fsync_no_super(struct block_device *); -struct buffer_head *__find_get_block(struct block_device *, sector_t, int); -struct buffer_head * __getblk(struct block_device *, sector_t, int); +struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block, + unsigned size); +struct buffer_head *__getblk(struct block_device *bdev, sector_t block, + unsigned size); void __brelse(struct buffer_head *); void __bforget(struct buffer_head *); -void __breadahead(struct block_device *, sector_t block, int size); -struct buffer_head *__bread(struct block_device *, sector_t block, int size); +void __breadahead(struct block_device *, sector_t block, unsigned int size); +struct buffer_head *__bread(struct block_device *, sector_t block, unsigned size); struct buffer_head *alloc_buffer_head(gfp_t gfp_flags); void free_buffer_head(struct buffer_head * bh); void FASTCALL(unlock_buffer(struct buffer_head *bh)); -- cgit v1.2.3