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author | Jan Kara <jack@suse.cz> | 2016-05-13 00:38:15 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2016-05-13 00:38:15 -0400 |
commit | aef39ab1534d1a07061e0ee7e428499e127232eb (patch) | |
tree | 9a749224ef5cf24d556f5f08bcae93714520c3c8 /fs/dax.c | |
parent | 816cd71b0c723a7296d14aadb8ff1ba42f6181d2 (diff) | |
download | linux-aef39ab1534d1a07061e0ee7e428499e127232eb.tar.bz2 |
dax: call get_blocks() with create == 1 for write faults to unwritten extents
Currently, __dax_fault() does not call get_blocks() callback with create
argument set, when we got back unwritten extent from the initial
get_blocks() call during a write fault. This is because originally
filesystems were supposed to convert unwritten extents to written ones
using complete_unwritten() callback. Later this was abandoned in favor of
using pre-zeroed blocks however the condition whether get_blocks() needs
to be called with create == 1 remained.
Fix the condition so that filesystems are not forced to zero-out and
convert unwritten extents when get_blocks() is called with create == 0
(which introduces unnecessary overhead for read faults and can be
problematic as the filesystem may possibly be read-only).
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/dax.c')
-rw-r--r-- | fs/dax.c | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -667,7 +667,7 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, if (error) goto unlock_page; - if (!buffer_mapped(&bh) && !buffer_unwritten(&bh) && !vmf->cow_page) { + if (!buffer_mapped(&bh) && !vmf->cow_page) { if (vmf->flags & FAULT_FLAG_WRITE) { error = get_block(inode, block, &bh, 1); count_vm_event(PGMAJFAULT); |