kernel.git/fs/gfs2/dir.h, branch linux-3.3.y

GFS2: Add readahead to sequential directory traversal

2011-11-08T09:52:12Z

This patch adds read-ahead capability to GFS2's directory hash table management. It greatly improves performance for some directory operations. For example: In one of my file systems that has 1000 directories, each of which has 1000 files, time to execute a recursive ls (time ls -fR /mnt/gfs2 > /dev/null) was reduced from 2m2.814s on a stock kernel to 0m45.938s. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse

GFS2: Cache dir hash table in a contiguous buffer

2011-07-15T08:31:48Z

This patch adds a cache for the hash table to the directory code in order to help simplify the way in which the hash table is accessed. This is intended to be a first step towards introducing some performance improvements in the directory code. There are two follow ups that I'm hoping to see fairly shortly. One is to simplify the hash table reading code now that we always read the complete hash table, whether we want one entry or all of them. The other is to introduce readahead on the heads of the hash chains which are referred to from the table. The hash table is a maximum of 128k in size, so it is not worth trying to read it in small chunks. Signed-off-by: Steven Whitehouse

GFS2: When adding a new dir entry, inc link count if it is a subdir

2011-05-09T15:43:53Z

This adds an increment of the link count when we add a new directory entry, if that entry is itself a directory. This means that we no longer need separate code to perform this operation. Now that both adding and removing directory entries automatically update the parent directory's link count if required, that makes the code shorter and simpler than before. Signed-off-by: Steven Whitehouse

GFS2: Make gfs2_dir_del update link count when required

2011-05-09T15:42:37Z

When we remove an entry from a directory, we can save ourselves some trouble if we know the type of the entry in question, since if it is itself a directory, we can update the link count of the parent at the same time as removing the directory entry. In addition this patch also merges the rmdir and unlink code which was almost identical anyway. This eliminates the calls to remove the . and .. directory entries on each rmdir (not needed since the directory will be deallocated, anyway) which was the only thing preventing passing the dentry to gfs2_dir_del(). The passing of the dentry rather than just the name allows us to figure out the type of the entry which is being removed, and thus adjust the link count when required. Signed-off-by: Steven Whitehouse

GFS2: Make . and .. qstrs constant

2010-09-20T10:21:09Z

Rather than calculating the qstrs for . and .. each time we need them, its better to keep a constant version of these and just refer to them when required. Signed-off-by: Steven Whitehouse Reviewed-by: Christoph Hellwig

GFS2: Fix bug in gfs2_lock_fs_check_clean()

2009-01-05T07:39:11Z

gfs2_lock_fs_check_clean() should not be calling gfs2_jindex_hold() since it doesn't work like rindex hold, despite the comment. That allows gfs2_jindex_hold() to be moved into ops_fstype.c where it can be made static. Signed-off-by: Steven Whitehouse

[GFS2] Clean up inode number handling

2007-07-09T07:22:24Z

This patch cleans up the inode number handling code. The main difference is that instead of looking up the inodes using a struct gfs2_inum_host we now use just the no_addr member of this structure. The tests relating to no_formal_ino can then be done by the calling code. This has advantages in that we want to do different things in different code paths if the no_formal_ino doesn't match. In the NFS patch we want to return -ESTALE, but in the ->lookup() path, its a bug in the fs if the no_formal_ino doesn't match and thus we can withdraw in this case. In order to later fix bz #201012, we need to be able to look up an inode without knowing no_formal_ino, as the only information that is known to us is the on-disk location of the inode in question. This patch will also help us to fix bz #236099 at a later date by cleaning up a lot of the code in that area. There are no user visible changes as a result of this patch and there are no changes to the on-disk format either. Signed-off-by: Steven Whitehouse

[GFS2] Clean up/speed up readdir

2007-02-05T18:37:04Z

This removes the extra filldir callback which gfs2 was using to enclose an attempt at readahead for inodes during readdir. The code was too complicated and also hurts performance badly in the case that the getdents64/readdir call isn't being followed by stat() and it wasn't even getting it right all the time when it was. As a result, on my test box an "ls" of a directory containing 250000 files fell from about 7mins (freshly mounted, so nothing cached) to between about 15 to 25 seconds. When the directory content was cached, the time taken fell from about 3mins to about 4 or 5 seconds. Interestingly in the cached case, running "ls -l" once reduced the time taken for subsequent runs of "ls" to about 6 secs even without this patch. Now it turns out that there was a special case of glocks being used for prefetching the metadata, but because of the timeouts for these locks (set to 10 secs) the metadata was being timed out before it was being used and this the prefetch code was constantly trying to prefetch the same data over and over. Calling "ls -l" meant that the inodes were brought into memory and once the inodes are cached, the glocks are not disposed of until the inodes are pushed out of the cache, thus extending the lifetime of the glocks, and thus bringing down the time for subsequent runs of "ls" considerably. Signed-off-by: Steven Whitehouse

[GFS2] split and annotate gfs2_inum

2006-11-30T15:33:32Z

Signed-off-by: Al Viro Signed-off-by: Steven Whitehouse

[GFS2] Make headers compile on their own

2006-09-05T14:39:21Z

As per Jan Engelhardt's comments, this should make all the headers compile on their own by including and/or declaring structures early. Cc: Jan Engelhardt Signed-off-by: Steven Whitehouse