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authorRoss Zwisler <ross.zwisler@linux.intel.com>2016-02-26 15:19:46 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-02-27 10:28:52 -0800
commit0a6cf9137ded4856b41910a4336677ee0ffa6736 (patch)
tree17e6633746bb665e35f9d682c626def34033ca31
parent03cdadb04077b9311bbc67d98cc5401aff76482d (diff)
downloadlinux-0a6cf9137ded4856b41910a4336677ee0ffa6736.tar.bz2
ext2, ext4: only set S_DAX for regular inodes
When S_DAX is set on an inode we assume that if there are pages attached to the mapping (mapping->nrpages != 0), those pages are clean zero pages that were used to service reads from holes. Any dirty data associated with the inode should be in the form of DAX exceptional entries (mapping->nrexceptional) that is written back via dax_writeback_mapping_range(). With the current code, though, this isn't always true. For example, ext2 and ext4 directory inodes can have S_DAX set, but have their dirty data stored as dirty page cache entries. For these types of inodes, having S_DAX set doesn't really make sense since their I/O doesn't actually happen through the DAX code path. Instead, only allow S_DAX to be set for regular inodes for ext2 and ext4. This allows us to have strict DAX vs non-DAX paths in the writeback code. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jens Axboe <axboe@fb.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ext2/inode.c2
-rw-r--r--fs/ext4/inode.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 338eefda70c6..27e2cdd4999b 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1296,7 +1296,7 @@ void ext2_set_inode_flags(struct inode *inode)
inode->i_flags |= S_NOATIME;
if (flags & EXT2_DIRSYNC_FL)
inode->i_flags |= S_DIRSYNC;
- if (test_opt(inode->i_sb, DAX))
+ if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
inode->i_flags |= S_DAX;
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9cc57c3b4661..5708e689e63d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4155,7 +4155,7 @@ void ext4_set_inode_flags(struct inode *inode)
new_fl |= S_NOATIME;
if (flags & EXT4_DIRSYNC_FL)
new_fl |= S_DIRSYNC;
- if (test_opt(inode->i_sb, DAX))
+ if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
new_fl |= S_DAX;
inode_set_flags(inode, new_fl,
S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);