[Ocfs2-devel] [PATCH 14/15] ocfs2: Read support for directories
with inline data
Mark Fasheh
mark.fasheh at oracle.com
Wed Sep 12 13:01:18 PDT 2007
This splits out extent based directory read support and implements
inline-data versions of those functions. All knowledge of inline-data versus
extent based directories is internalized. For lookups the code uses
ocfs2_find_entry_id(), full dir iterations make use of
ocfs2_dir_foreach_blk_id().
Signed-off-by: Mark Fasheh <mark.fasheh at oracle.com>
---
fs/ocfs2/dir.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 168 insertions(+), 8 deletions(-)
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 4c36eae..f7aaf4e 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -81,6 +81,10 @@ static int ocfs2_do_extend_dir(struct super_block *sb,
struct ocfs2_alloc_context *meta_ac,
struct buffer_head **new_bh);
+/*
+ * bh passed here can be an inode block or a dir data block, depending
+ * on the inode inline data flag.
+ */
static int ocfs2_check_dir_entry(struct inode * dir,
struct ocfs2_dir_entry * de,
struct buffer_head * bh,
@@ -125,6 +129,8 @@ static int inline ocfs2_search_dirblock(struct buffer_head *bh,
struct inode *dir,
const char *name, int namelen,
unsigned long offset,
+ char *first_de,
+ unsigned int bytes,
struct ocfs2_dir_entry **res_dir)
{
struct ocfs2_dir_entry *de;
@@ -134,8 +140,8 @@ static int inline ocfs2_search_dirblock(struct buffer_head *bh,
mlog_entry_void();
- de_buf = bh->b_data;
- dlimit = de_buf + dir->i_sb->s_blocksize;
+ de_buf = first_de;
+ dlimit = de_buf + bytes;
while (de_buf < dlimit) {
/* this code is executed quadratically often */
@@ -171,9 +177,39 @@ bail:
return ret;
}
-struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
- struct inode *dir,
- struct ocfs2_dir_entry **res_dir)
+static struct buffer_head *ocfs2_find_entry_id(const char *name,
+ int namelen,
+ struct inode *dir,
+ struct ocfs2_dir_entry **res_dir)
+{
+ int ret, found;
+ struct buffer_head *di_bh = NULL;
+ struct ocfs2_dinode *di;
+ struct ocfs2_inline_data *data;
+
+ ret = ocfs2_read_block(OCFS2_SB(dir->i_sb), OCFS2_I(dir)->ip_blkno,
+ &di_bh, OCFS2_BH_CACHED, dir);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ di = (struct ocfs2_dinode *)di_bh->b_data;
+ data = &di->id2.i_data;
+
+ found = ocfs2_search_dirblock(di_bh, dir, name, namelen, 0,
+ data->id_data, i_size_read(dir), res_dir);
+ if (found == 1)
+ return di_bh;
+
+ brelse(di_bh);
+out:
+ return NULL;
+}
+
+struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen,
+ struct inode *dir,
+ struct ocfs2_dir_entry **res_dir)
{
struct super_block *sb;
struct buffer_head *bh_use[NAMEI_RA_SIZE];
@@ -188,7 +224,6 @@ struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
mlog_entry_void();
- *res_dir = NULL;
sb = dir->i_sb;
nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
@@ -236,6 +271,7 @@ restart:
}
i = ocfs2_search_dirblock(bh, dir, name, namelen,
block << sb->s_blocksize_bits,
+ bh->b_data, sb->s_blocksize,
res_dir);
if (i == 1) {
OCFS2_I(dir)->ip_dir_start_lookup = block;
@@ -271,6 +307,30 @@ cleanup_and_exit:
return ret;
}
+/*
+ * Try to find an entry of the provided name within 'dir'.
+ *
+ * If nothing was found, NULL is returned. Otherwise, a buffer_head
+ * and pointer to the dir entry are passed back.
+ *
+ * Caller can NOT assume anything about the contents of the
+ * buffer_head - it is passed back only so that it can be passed into
+ * any one of the manipulation functions (add entry, delete entry,
+ * etc). As an example, bh in the extent directory case is a data
+ * block, in the inline-data case it actually points to an inode.
+ */
+struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
+ struct inode *dir,
+ struct ocfs2_dir_entry **res_dir)
+{
+ *res_dir = NULL;
+
+ if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
+ return ocfs2_find_entry_id(name, namelen, dir, res_dir);
+
+ return ocfs2_find_entry_el(name, namelen, dir, res_dir);
+}
+
int ocfs2_update_entry(struct inode *dir, handle_t *handle,
struct buffer_head *de_bh, struct ocfs2_dir_entry *de,
struct inode *new_entry_inode)
@@ -459,8 +519,98 @@ bail:
return retval;
}
-static int ocfs2_dir_foreach_blk(struct inode *inode, unsigned long *f_version,
- loff_t *f_pos, void *priv, filldir_t filldir)
+static int ocfs2_dir_foreach_blk_id(struct inode *inode,
+ unsigned long *f_version,
+ loff_t *f_pos, void *priv,
+ filldir_t filldir)
+{
+ int ret, i, filldir_ret;
+ unsigned long offset = *f_pos;
+ struct buffer_head *di_bh = NULL;
+ struct ocfs2_dinode *di;
+ struct ocfs2_inline_data *data;
+ struct ocfs2_dir_entry *de;
+
+ ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno,
+ &di_bh, OCFS2_BH_CACHED, inode);
+ if (ret) {
+ mlog(ML_ERROR, "Unable to read inode block for dir %llu\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ goto out;
+ }
+
+ di = (struct ocfs2_dinode *)di_bh->b_data;
+ data = &di->id2.i_data;
+
+ while (*f_pos < i_size_read(inode)) {
+revalidate:
+ /* If the dir block has changed since the last call to
+ * readdir(2), then we might be pointing to an invalid
+ * dirent right now. Scan from the start of the block
+ * to make sure. */
+ if (*f_version != inode->i_version) {
+ for (i = 0; i < i_size_read(inode) && i < offset; ) {
+ de = (struct ocfs2_dir_entry *)
+ (data->id_data + i);
+ /* It's too expensive to do a full
+ * dirent test each time round this
+ * loop, but we do have to test at
+ * least that it is non-zero. A
+ * failure will be detected in the
+ * dirent test below. */
+ if (le16_to_cpu(de->rec_len) <
+ OCFS2_DIR_REC_LEN(1))
+ break;
+ i += le16_to_cpu(de->rec_len);
+ }
+ *f_pos = offset = i;
+ *f_version = inode->i_version;
+ }
+
+ de = (struct ocfs2_dir_entry *) (data->id_data + *f_pos);
+ if (!ocfs2_check_dir_entry(inode, de, di_bh, *f_pos)) {
+ /* On error, skip the f_pos to the end. */
+ *f_pos = i_size_read(inode);
+ goto out;
+ }
+ offset += le16_to_cpu(de->rec_len);
+ if (le64_to_cpu(de->inode)) {
+ /* We might block in the next section
+ * if the data destination is
+ * currently swapped out. So, use a
+ * version stamp to detect whether or
+ * not the directory has been modified
+ * during the copy operation.
+ */
+ unsigned long version = *f_version;
+ unsigned char d_type = DT_UNKNOWN;
+
+ if (de->file_type < OCFS2_FT_MAX)
+ d_type = ocfs2_filetype_table[de->file_type];
+
+ filldir_ret = filldir(priv, de->name,
+ de->name_len,
+ *f_pos,
+ le64_to_cpu(de->inode),
+ d_type);
+ if (filldir_ret)
+ break;
+ if (version != *f_version)
+ goto revalidate;
+ }
+ *f_pos += le16_to_cpu(de->rec_len);
+ }
+
+out:
+ brelse(di_bh);
+
+ return 0;
+}
+
+static int ocfs2_dir_foreach_blk_el(struct inode *inode,
+ unsigned long *f_version,
+ loff_t *f_pos, void *priv,
+ filldir_t filldir)
{
int error = 0;
unsigned long offset, blk, last_ra_blk = 0;
@@ -576,6 +726,16 @@ out:
return stored;
}
+static int ocfs2_dir_foreach_blk(struct inode *inode, unsigned long *f_version,
+ loff_t *f_pos, void *priv, filldir_t filldir)
+{
+ if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
+ return ocfs2_dir_foreach_blk_id(inode, f_version, f_pos, priv,
+ filldir);
+
+ return ocfs2_dir_foreach_blk_el(inode, f_version, f_pos, priv, filldir);
+}
+
/*
* This is intended to be called from inside other kernel functions,
* so we fake some arguments.
--
1.5.0.6
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