From 97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 14 Jan 2015 10:42:31 +0100 Subject: fs: kill BDI_CAP_SWAP_BACKED This bdi flag isn't too useful - we can determine that a vma is backed by either swap or shmem trivially in the caller. This also allows removing the backing_dev_info instaces for swap and shmem in favor of noop_backing_dev_info. Signed-off-by: Christoph Hellwig Reviewed-by: Tejun Heo Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- mm/madvise.c | 17 ++++++++++------- mm/shmem.c | 25 +++++++------------------ mm/swap.c | 2 -- mm/swap_state.c | 7 +------ 4 files changed, 18 insertions(+), 33 deletions(-) (limited to 'mm') diff --git a/mm/madvise.c b/mm/madvise.c index a271adc93289..1383a8916bc3 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -222,19 +222,22 @@ static long madvise_willneed(struct vm_area_struct *vma, struct file *file = vma->vm_file; #ifdef CONFIG_SWAP - if (!file || mapping_cap_swap_backed(file->f_mapping)) { + if (!file) { *prev = vma; - if (!file) - force_swapin_readahead(vma, start, end); - else - force_shm_swapin_readahead(vma, start, end, - file->f_mapping); + force_swapin_readahead(vma, start, end); return 0; } -#endif + if (shmem_mapping(file->f_mapping)) { + *prev = vma; + force_shm_swapin_readahead(vma, start, end, + file->f_mapping); + return 0; + } +#else if (!file) return -EBADF; +#endif if (file->f_mapping->a_ops->get_xip_mem) { /* no bad return value, but ignore advice */ diff --git a/mm/shmem.c b/mm/shmem.c index 73ba1df7c8ba..1b77eaf589fd 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -191,11 +191,6 @@ static const struct inode_operations shmem_dir_inode_operations; static const struct inode_operations shmem_special_inode_operations; static const struct vm_operations_struct shmem_vm_ops; -static struct backing_dev_info shmem_backing_dev_info __read_mostly = { - .ra_pages = 0, /* No readahead */ - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, -}; - static LIST_HEAD(shmem_swaplist); static DEFINE_MUTEX(shmem_swaplist_mutex); @@ -765,11 +760,11 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) goto redirty; /* - * shmem_backing_dev_info's capabilities prevent regular writeback or - * sync from ever calling shmem_writepage; but a stacking filesystem - * might use ->writepage of its underlying filesystem, in which case - * tmpfs should write out to swap only in response to memory pressure, - * and not for the writeback threads or sync. + * Our capabilities prevent regular writeback or sync from ever calling + * shmem_writepage; but a stacking filesystem might use ->writepage of + * its underlying filesystem, in which case tmpfs should write out to + * swap only in response to memory pressure, and not for the writeback + * threads or sync. */ if (!wbc->for_reclaim) { WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ @@ -1415,7 +1410,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode inode->i_ino = get_next_ino(); inode_init_owner(inode, dir, mode); inode->i_blocks = 0; - inode->i_mapping->backing_dev_info = &shmem_backing_dev_info; + inode->i_mapping->backing_dev_info = &noop_backing_dev_info; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_generation = get_seconds(); info = SHMEM_I(inode); @@ -1461,7 +1456,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode bool shmem_mapping(struct address_space *mapping) { - return mapping->backing_dev_info == &shmem_backing_dev_info; + return mapping->host->i_sb->s_op == &shmem_ops; } #ifdef CONFIG_TMPFS @@ -3226,10 +3221,6 @@ int __init shmem_init(void) if (shmem_inode_cachep) return 0; - error = bdi_init(&shmem_backing_dev_info); - if (error) - goto out4; - error = shmem_init_inodecache(); if (error) goto out3; @@ -3253,8 +3244,6 @@ out1: out2: shmem_destroy_inodecache(); out3: - bdi_destroy(&shmem_backing_dev_info); -out4: shm_mnt = ERR_PTR(error); return error; } diff --git a/mm/swap.c b/mm/swap.c index 8a12b33936b4..4e0109a2f37b 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -1138,8 +1138,6 @@ void __init swap_setup(void) #ifdef CONFIG_SWAP int i; - if (bdi_init(swapper_spaces[0].backing_dev_info)) - panic("Failed to init swap bdi"); for (i = 0; i < MAX_SWAPFILES; i++) { spin_lock_init(&swapper_spaces[i].tree_lock); INIT_LIST_HEAD(&swapper_spaces[i].i_mmap_nonlinear); diff --git a/mm/swap_state.c b/mm/swap_state.c index 9711342987a0..1c137b69ecde 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -32,17 +32,12 @@ static const struct address_space_operations swap_aops = { #endif }; -static struct backing_dev_info swap_backing_dev_info = { - .name = "swap", - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, -}; - struct address_space swapper_spaces[MAX_SWAPFILES] = { [0 ... MAX_SWAPFILES - 1] = { .page_tree = RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN), .i_mmap_writable = ATOMIC_INIT(0), .a_ops = &swap_aops, - .backing_dev_info = &swap_backing_dev_info, + .backing_dev_info = &noop_backing_dev_info, } }; -- cgit v1.2.3