diff options
author | Josef Bacik <josef@toxicpanda.com> | 2021-02-10 17:14:33 -0500 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2021-04-19 17:25:15 +0200 |
commit | 8318ba79eeeb1ab69bea1cc4386d5a185abc0cb8 (patch) | |
tree | d756fbc9eafc402abbb4b94e3983a760ffbdd5d2 /fs/btrfs/inode.c | |
parent | 5e295768a0c6086901250b6be22f14eb01232ba1 (diff) | |
download | linux-8318ba79eeeb1ab69bea1cc4386d5a185abc0cb8.tar.bz2 |
btrfs: add a i_mmap_lock to our inode
We need to be able to exclude page_mkwrite from happening concurrently
with certain operations. To facilitate this, add a i_mmap_lock to our
inode, down_read() it in our mkwrite, and add a new ILOCK flag to
indicate that we want to take the i_mmap_lock as well. I used pahole to
check the size of the btrfs_inode, the sizes are as follows
no lockdep:
before: 1120 (3 per 4k page)
after: 1160 (3 per 4k page)
lockdep:
before: 2072 (1 per 4k page)
after: 2224 (1 per 4k page)
We're slightly larger but it doesn't change how many objects we can fit
per page.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/inode.c')
-rw-r--r-- | fs/btrfs/inode.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index df38540d7550..93f735ca96cf 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -102,6 +102,7 @@ static void __endio_write_update_ordered(struct btrfs_inode *inode, * BTRFS_ILOCK_SHARED - acquire a shared lock on the inode * BTRFS_ILOCK_TRY - try to acquire the lock, if fails on first attempt * return -EAGAIN + * BTRFS_ILOCK_MMAP - acquire a write lock on the i_mmap_lock */ int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags) { @@ -122,6 +123,8 @@ int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags) } inode_lock(inode); } + if (ilock_flags & BTRFS_ILOCK_MMAP) + down_write(&BTRFS_I(inode)->i_mmap_lock); return 0; } @@ -133,6 +136,8 @@ int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags) */ void btrfs_inode_unlock(struct inode *inode, unsigned int ilock_flags) { + if (ilock_flags & BTRFS_ILOCK_MMAP) + up_write(&BTRFS_I(inode)->i_mmap_lock); if (ilock_flags & BTRFS_ILOCK_SHARED) inode_unlock_shared(inode); else @@ -8540,6 +8545,7 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ again: + down_read(&BTRFS_I(inode)->i_mmap_lock); lock_page(page); size = i_size_read(inode); @@ -8568,6 +8574,7 @@ again: unlock_extent_cached(io_tree, page_start, page_end, &cached_state); unlock_page(page); + up_read(&BTRFS_I(inode)->i_mmap_lock); btrfs_start_ordered_extent(ordered, 1); btrfs_put_ordered_extent(ordered); goto again; @@ -8625,6 +8632,7 @@ again: BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; unlock_extent_cached(io_tree, page_start, page_end, &cached_state); + up_read(&BTRFS_I(inode)->i_mmap_lock); btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); sb_end_pagefault(inode->i_sb); @@ -8633,6 +8641,7 @@ again: out_unlock: unlock_page(page); + up_read(&BTRFS_I(inode)->i_mmap_lock); out: btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start, @@ -8884,6 +8893,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) INIT_LIST_HEAD(&ei->delalloc_inodes); INIT_LIST_HEAD(&ei->delayed_iput); RB_CLEAR_NODE(&ei->rb_node); + init_rwsem(&ei->i_mmap_lock); return inode; } |