diff options
| -rw-r--r-- | fs/gfs2/dir.c | 56 | ||||
| -rw-r--r-- | fs/gfs2/dir.h | 2 | ||||
| -rw-r--r-- | fs/gfs2/export.c | 3 | ||||
| -rw-r--r-- | fs/gfs2/file.c | 2 |
4 files changed, 57 insertions, 6 deletions
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c index 8ccad24..9144117 100644 --- a/fs/gfs2/dir.c +++ b/fs/gfs2/dir.c @@ -76,6 +76,8 @@ #define IS_LEAF 1 /* Hashed (leaf) directory */ #define IS_DINODE 2 /* Linear (stuffed dinode block) directory */ +#define MAX_RA_BLOCKS 32 /* max read-ahead blocks */ + #define gfs2_disk_hash2offset(h) (((u64)(h)) >> 1) #define gfs2_dir_offset2hash(p) ((u32)(((u64)(p)) << 1)) @@ -1376,6 +1378,50 @@ out: return error; } +/* gfs2_dir_readahead - Issue read-ahead requests for leaf blocks. + * + * Note: we can't calculate each index like dir_e_read can because we don't + * have the leaf, and therefore we don't have the depth, and therefore we + * don't have the length. So we have to just read enough ahead to make up + * for the loss of information. */ +static void gfs2_dir_readahead(struct inode *inode, unsigned hsize, u32 index, + struct file_ra_state *f_ra) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_glock *gl = ip->i_gl; + struct buffer_head *bh; + u64 blocknr = 0, last; + unsigned count; + + /* First check if we've already read-ahead for the whole range. */ + if (!f_ra || index + MAX_RA_BLOCKS < f_ra->start) + return; + + f_ra->start = max((pgoff_t)index, f_ra->start); + for (count = 0; count < MAX_RA_BLOCKS; count++) { + if (f_ra->start >= hsize) /* if exceeded the hash table */ + break; + + last = blocknr; + blocknr = be64_to_cpu(ip->i_hash_cache[f_ra->start]); + f_ra->start++; + if (blocknr == last) + continue; + + bh = gfs2_getbuf(gl, blocknr, 1); + if (trylock_buffer(bh)) { + if (buffer_uptodate(bh)) { + unlock_buffer(bh); + brelse(bh); + continue; + } + bh->b_end_io = end_buffer_read_sync; + submit_bh(READA | REQ_META, bh); + continue; + } + brelse(bh); + } +} /** * dir_e_read - Reads the entries from a directory into a filldir buffer @@ -1388,7 +1434,7 @@ out: */ static int dir_e_read(struct inode *inode, u64 *offset, void *opaque, - filldir_t filldir) + filldir_t filldir, struct file_ra_state *f_ra) { struct gfs2_inode *dip = GFS2_I(inode); u32 hsize, len = 0; @@ -1402,10 +1448,14 @@ static int dir_e_read(struct inode *inode, u64 *offset, void *opaque, hash = gfs2_dir_offset2hash(*offset); index = hash >> (32 - dip->i_depth); + if (f_ra && dip->i_hash_cache == NULL) + f_ra->start = 0; lp = gfs2_dir_get_hash_table(dip); if (IS_ERR(lp)) return PTR_ERR(lp); + gfs2_dir_readahead(inode, hsize, index, f_ra); + while (index < hsize) { error = gfs2_dir_read_leaf(inode, offset, opaque, filldir, &copied, &depth, @@ -1423,7 +1473,7 @@ static int dir_e_read(struct inode *inode, u64 *offset, void *opaque, } int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque, - filldir_t filldir) + filldir_t filldir, struct file_ra_state *f_ra) { struct gfs2_inode *dip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); @@ -1437,7 +1487,7 @@ int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque, return 0; if (dip->i_diskflags & GFS2_DIF_EXHASH) - return dir_e_read(inode, offset, opaque, filldir); + return dir_e_read(inode, offset, opaque, filldir, f_ra); if (!gfs2_is_stuffed(dip)) { gfs2_consist_inode(dip); diff --git a/fs/gfs2/dir.h b/fs/gfs2/dir.h index ff5772f..98c960b 100644 --- a/fs/gfs2/dir.h +++ b/fs/gfs2/dir.h @@ -25,7 +25,7 @@ extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename, const struct gfs2_inode *ip); extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry); extern int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque, - filldir_t filldir); + filldir_t filldir, struct file_ra_state *f_ra); extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename, const struct gfs2_inode *nip, unsigned int new_type); diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index fe9945f..70ba891 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -99,6 +99,7 @@ static int gfs2_get_name(struct dentry *parent, char *name, struct gfs2_holder gh; u64 offset = 0; int error; + struct file_ra_state f_ra = { .start = 0 }; if (!dir) return -EINVAL; @@ -118,7 +119,7 @@ static int gfs2_get_name(struct dentry *parent, char *name, if (error) return error; - error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir); + error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir, &f_ra); gfs2_glock_dq_uninit(&gh); diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index ce36a56..46f6f9a 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -105,7 +105,7 @@ static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir) return error; } - error = gfs2_dir_read(dir, &offset, dirent, filldir); + error = gfs2_dir_read(dir, &offset, dirent, filldir, &file->f_ra); gfs2_glock_dq_uninit(&d_gh); |
