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authorSteven Whitehouse <swhiteho@redhat.com>2010-07-28 17:56:23 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2010-07-28 11:10:03 -0700
commitd2a97a4e99ff0ffdccd1fc46f22fb34270ef1e56 (patch)
treef9ac90f438bb3221a6e383e7f1c9c817e95ad44b
parentfc0f5ac8fe693d1b05f5a928cc48135d1c8b7f2e (diff)
GFS2: Use kmalloc when possible for ->readdir()
If we don't need a huge amount of memory in ->readdir() then we can use kmalloc rather than vmalloc to allocate it. This should cut down on the greater overheads associated with vmalloc for smaller directories. We may be able to eliminate vmalloc entirely at some stage, but this is easy to do right away. Also using GFP_NOFS to avoid any issues wrt to deleting inodes while under a glock, and suggestion from Linus to factor out the alloc/dealloc. I've given this a test with a variety of different sized directories and it seems to work ok. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/gfs2/dir.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 26ca3361a8bc..6b48d7c268b2 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -1231,6 +1231,25 @@ static int do_filldir_main(struct gfs2_inode *dip, u64 *offset,
return 0;
}
+static void *gfs2_alloc_sort_buffer(unsigned size)
+{
+ void *ptr = NULL;
+
+ if (size < KMALLOC_MAX_SIZE)
+ ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN);
+ if (!ptr)
+ ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL);
+ return ptr;
+}
+
+static void gfs2_free_sort_buffer(void *ptr)
+{
+ if (is_vmalloc_addr(ptr))
+ vfree(ptr);
+ else
+ kfree(ptr);
+}
+
static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
filldir_t filldir, int *copied, unsigned *depth,
u64 leaf_no)
@@ -1271,7 +1290,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
* 99 is the maximum number of entries that can fit in a single
* leaf block.
*/
- larr = vmalloc((leaves + entries + 99) * sizeof(void *));
+ larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *));
if (!larr)
goto out;
darr = (const struct gfs2_dirent **)(larr + leaves);
@@ -1282,7 +1301,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
do {
error = get_leaf(ip, lfn, &bh);
if (error)
- goto out_kfree;
+ goto out_free;
lf = (struct gfs2_leaf *)bh->b_data;
lfn = be64_to_cpu(lf->lf_next);
if (lf->lf_entries) {
@@ -1291,7 +1310,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
gfs2_dirent_gather, NULL, &g);
error = PTR_ERR(dent);
if (IS_ERR(dent))
- goto out_kfree;
+ goto out_free;
if (entries2 != g.offset) {
fs_warn(sdp, "Number of entries corrupt in dir "
"leaf %llu, entries2 (%u) != "
@@ -1300,7 +1319,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
entries2, g.offset);
error = -EIO;
- goto out_kfree;
+ goto out_free;
}
error = 0;
larr[leaf++] = bh;
@@ -1312,10 +1331,10 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque,
BUG_ON(entries2 != entries);
error = do_filldir_main(ip, offset, opaque, filldir, darr,
entries, copied);
-out_kfree:
+out_free:
for(i = 0; i < leaf; i++)
brelse(larr[i]);
- vfree(larr);
+ gfs2_free_sort_buffer(larr);
out:
return error;
}

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