aboutsummaryrefslogtreecommitdiff
path: root/fs/ext4/namei.c
diff options
context:
space:
mode:
authorAndreas Dilger <adilger@clusterfs.com>2007-07-18 08:38:01 -0400
committerTheodore Ts'o <tytso@mit.edu>2007-07-18 08:38:01 -0400
commitf8628a14a27eb4512a1ede43de1d9db4d9f92bc3 (patch)
tree45719452db34112382a1b3e83dc648abe45eac70 /fs/ext4/namei.c
parent6dd4ee7cab7e3a17c571aebd444f4344c8c4946e (diff)
downloadlinux-linaro-f8628a14a27eb4512a1ede43de1d9db4d9f92bc3.tar.gz
ext4: Remove 65000 subdirectory limit
This patch adds support to ext4 for allowing more than 65000 subdirectories. Currently the maximum number of subdirectories is capped at 32000. If we exceed 65000 subdirectories in an htree directory it sets the inode link count to 1 and no longer counts subdirectories. The directory link count is not actually used when determining if a directory is empty, as that only counts subdirectories and not regular files that might be in there. A EXT4_FEATURE_RO_COMPAT_DIR_NLINK flag has been added and it is set if the subdir count for any directory crosses 65000. A later fsck will clear EXT4_FEATURE_RO_COMPAT_DIR_NLINK if there are no longer any directory with >65000 subdirs. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/namei.c')
-rw-r--r--fs/ext4/namei.c60
1 files changed, 46 insertions, 14 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 40106b7ea4b..da224974af7 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1629,6 +1629,35 @@ static int ext4_delete_entry (handle_t *handle,
return -ENOENT;
}
+/*
+ * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
+ * since this indicates that nlinks count was previously 1.
+ */
+static void ext4_inc_count(handle_t *handle, struct inode *inode)
+{
+ inc_nlink(inode);
+ if (is_dx(inode) && inode->i_nlink > 1) {
+ /* limit is 16-bit i_links_count */
+ if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
+ inode->i_nlink = 1;
+ EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
+ }
+ }
+}
+
+/*
+ * If a directory had nlink == 1, then we should let it be 1. This indicates
+ * directory has >EXT4_LINK_MAX subdirs.
+ */
+static void ext4_dec_count(handle_t *handle, struct inode *inode)
+{
+ drop_nlink(inode);
+ if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
+ inc_nlink(inode);
+}
+
+
static int ext4_add_nondir(handle_t *handle,
struct dentry *dentry, struct inode *inode)
{
@@ -1725,7 +1754,7 @@ static int ext4_mkdir(struct inode * dir, struct dentry * dentry, int mode)
struct ext4_dir_entry_2 * de;
int err, retries = 0;
- if (dir->i_nlink >= EXT4_LINK_MAX)
+ if (EXT4_DIR_LINK_MAX(dir))
return -EMLINK;
retry:
@@ -1748,7 +1777,7 @@ retry:
inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
dir_block = ext4_bread (handle, inode, 0, 1, &err);
if (!dir_block) {
- drop_nlink(inode); /* is this nlink == 0? */
+ ext4_dec_count(handle, inode); /* is this nlink == 0? */
ext4_mark_inode_dirty(handle, inode);
iput (inode);
goto out_stop;
@@ -1780,7 +1809,7 @@ retry:
iput (inode);
goto out_stop;
}
- inc_nlink(dir);
+ ext4_inc_count(handle, dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
d_instantiate(dentry, inode);
@@ -2045,9 +2074,9 @@ static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
retval = ext4_delete_entry(handle, dir, de, bh);
if (retval)
goto end_rmdir;
- if (inode->i_nlink != 2)
+ if (!EXT4_DIR_LINK_EMPTY(inode))
ext4_warning (inode->i_sb, "ext4_rmdir",
- "empty directory has nlink!=2 (%d)",
+ "empty directory has too many links (%d)",
inode->i_nlink);
inode->i_version++;
clear_nlink(inode);
@@ -2058,7 +2087,7 @@ static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
ext4_orphan_add(handle, inode);
inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
- drop_nlink(dir);
+ ext4_dec_count(handle, dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
@@ -2109,7 +2138,7 @@ static int ext4_unlink(struct inode * dir, struct dentry *dentry)
dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
ext4_update_dx_flag(dir);
ext4_mark_inode_dirty(handle, dir);
- drop_nlink(inode);
+ ext4_dec_count(handle, inode);
if (!inode->i_nlink)
ext4_orphan_add(handle, inode);
inode->i_ctime = ext4_current_time(inode);
@@ -2159,7 +2188,7 @@ retry:
err = __page_symlink(inode, symname, l,
mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
if (err) {
- drop_nlink(inode);
+ ext4_dec_count(handle, inode);
ext4_mark_inode_dirty(handle, inode);
iput (inode);
goto out_stop;
@@ -2185,8 +2214,9 @@ static int ext4_link (struct dentry * old_dentry,
struct inode *inode = old_dentry->d_inode;
int err, retries = 0;
- if (inode->i_nlink >= EXT4_LINK_MAX)
+ if (EXT4_DIR_LINK_MAX(inode))
return -EMLINK;
+
/*
* Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing
* otherwise has the potential to corrupt the orphan inode list.
@@ -2204,7 +2234,7 @@ retry:
handle->h_sync = 1;
inode->i_ctime = ext4_current_time(inode);
- inc_nlink(inode);
+ ext4_inc_count(handle, inode);
atomic_inc(&inode->i_count);
err = ext4_add_nondir(handle, dentry, inode);
@@ -2337,7 +2367,7 @@ static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
}
if (new_inode) {
- drop_nlink(new_inode);
+ ext4_dec_count(handle, new_inode);
new_inode->i_ctime = ext4_current_time(new_inode);
}
old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
@@ -2348,11 +2378,13 @@ static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
BUFFER_TRACE(dir_bh, "call ext4_journal_dirty_metadata");
ext4_journal_dirty_metadata(handle, dir_bh);
- drop_nlink(old_dir);
+ ext4_dec_count(handle, old_dir);
if (new_inode) {
- drop_nlink(new_inode);
+ /* checked empty_dir above, can't have another parent,
+ * ext3_dec_count() won't work for many-linked dirs */
+ new_inode->i_nlink = 0;
} else {
- inc_nlink(new_dir);
+ ext4_inc_count(handle, new_dir);
ext4_update_dx_flag(new_dir);
ext4_mark_inode_dirty(handle, new_dir);
}