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-rw-r--r--fs/ext4/ext4.h17
-rw-r--r--fs/ext4/extents.c73
-rw-r--r--fs/ext4/extents_status.c72
-rw-r--r--fs/ext4/ioctl.c3
4 files changed, 136 insertions, 29 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index c74b194..635135e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -561,15 +561,16 @@ enum {
#define EXT4_GET_BLOCKS_NO_PUT_HOLE 0x0200
/*
- * The bit position of this flag must not overlap with any of the
- * EXT4_GET_BLOCKS_*. It is used by ext4_ext_find_extent(),
+ * The bit position of these flags must not overlap with any of the
+ * EXT4_GET_BLOCKS_*. They are used by ext4_ext_find_extent(),
* read_extent_tree_block(), ext4_split_extent_at(),
- * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf() to
- * indicate that the we shouldn't be caching the extents when reading
- * from the extent tree while a truncate or punch hole operation
- * is in progress.
+ * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
+ * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
+ * caching the extents when reading from the extent tree while a
+ * truncate or punch hole operation is in progress.
*/
#define EXT4_EX_NOCACHE 0x0400
+#define EXT4_EX_FORCE_CACHE 0x0800
/*
* Flags used by ext4_free_blocks
@@ -601,6 +602,7 @@ enum {
#define EXT4_IOC_MOVE_EXT _IOWR('f', 15, struct move_extent)
#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
#define EXT4_IOC_SWAP_BOOT _IO('f', 17)
+#define EXT4_IOC_PRECACHE_EXTENTS _IO('f', 18)
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
@@ -1386,6 +1388,7 @@ enum {
nolocking */
EXT4_STATE_MAY_INLINE_DATA, /* may have in-inode data */
EXT4_STATE_ORDERED_MODE, /* data=ordered mode */
+ EXT4_STATE_EXT_PRECACHED, /* extents have been precached */
};
#define EXT4_INODE_BIT_FNS(name, field, offset) \
@@ -2705,7 +2708,7 @@ extern int ext4_find_delalloc_range(struct inode *inode,
extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len);
-
+extern int ext4_ext_precache(struct inode *inode);
/* move_extent.c */
extern void ext4_double_down_write_data_sem(struct inode *first,
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 08c1ac9..0183887 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -482,7 +482,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
if (err < 0)
goto errout;
}
- if (buffer_verified(bh))
+ if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
return bh;
err = __ext4_ext_check(function, line, inode,
ext_block_hdr(bh), depth, pblk);
@@ -526,6 +526,71 @@ errout:
__read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
(depth), (flags))
+/*
+ * This function is called to cache a file's extent information in the
+ * extent status tree
+ */
+int ext4_ext_precache(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_ext_path *path = NULL;
+ struct buffer_head *bh;
+ int i = 0, depth, ret = 0;
+
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return 0; /* not an extent-mapped inode */
+
+ down_read(&ei->i_data_sem);
+ depth = ext_depth(inode);
+
+ path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
+ GFP_NOFS);
+ if (path == NULL) {
+ up_read(&ei->i_data_sem);
+ return -ENOMEM;
+ }
+
+ /* Don't cache anything if there are no external extent blocks */
+ if (depth == 0)
+ goto out;
+ path[0].p_hdr = ext_inode_hdr(inode);
+ ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
+ if (ret)
+ goto out;
+ path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
+ while (i >= 0) {
+ /*
+ * If this is a leaf block or we've reached the end of
+ * the index block, go up
+ */
+ if ((i == depth) ||
+ path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
+ brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ continue;
+ }
+ bh = read_extent_tree_block(inode,
+ ext4_idx_pblock(path[i].p_idx++),
+ depth - i - 1,
+ EXT4_EX_FORCE_CACHE);
+ if (IS_ERR(bh)) {
+ ret = PTR_ERR(bh);
+ break;
+ }
+ i++;
+ path[i].p_bh = bh;
+ path[i].p_hdr = ext_block_hdr(bh);
+ path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
+ }
+ ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
+out:
+ up_read(&ei->i_data_sem);
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ return ret;
+}
+
#ifdef EXT_DEBUG
static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
{
@@ -4766,6 +4831,12 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
return error;
}
+ if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
+ error = ext4_ext_precache(inode);
+ if (error)
+ return error;
+ }
+
/* fallback to generic here if not in extents fmt */
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
return generic_block_fiemap(inode, fieinfo, start, len,
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 1dc5df0..0e88a36 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -710,11 +710,8 @@ void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
write_lock(&EXT4_I(inode)->i_es_lock);
es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
- if (es && ((es->es_lblk <= lblk) || (es->es_lblk <= end)))
- goto out;
-
- __es_insert_extent(inode, &newes);
-out:
+ if (!es || es->es_lblk > end)
+ __es_insert_extent(inode, &newes);
write_unlock(&EXT4_I(inode)->i_es_lock);
}
@@ -930,6 +927,12 @@ static int ext4_inode_touch_time_cmp(void *priv, struct list_head *a,
eia = list_entry(a, struct ext4_inode_info, i_es_lru);
eib = list_entry(b, struct ext4_inode_info, i_es_lru);
+ if (ext4_test_inode_state(&eia->vfs_inode, EXT4_STATE_EXT_PRECACHED) &&
+ !ext4_test_inode_state(&eib->vfs_inode, EXT4_STATE_EXT_PRECACHED))
+ return 1;
+ if (!ext4_test_inode_state(&eia->vfs_inode, EXT4_STATE_EXT_PRECACHED) &&
+ ext4_test_inode_state(&eib->vfs_inode, EXT4_STATE_EXT_PRECACHED))
+ return -1;
if (eia->i_touch_when == eib->i_touch_when)
return 0;
if (time_after(eia->i_touch_when, eib->i_touch_when))
@@ -943,21 +946,13 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
{
struct ext4_inode_info *ei;
struct list_head *cur, *tmp;
- LIST_HEAD(skiped);
+ LIST_HEAD(skipped);
int ret, nr_shrunk = 0;
+ int retried = 0, skip_precached = 1, nr_skipped = 0;
spin_lock(&sbi->s_es_lru_lock);
- /*
- * If the inode that is at the head of LRU list is newer than
- * last_sorted time, that means that we need to sort this list.
- */
- ei = list_first_entry(&sbi->s_es_lru, struct ext4_inode_info, i_es_lru);
- if (sbi->s_es_last_sorted < ei->i_touch_when) {
- list_sort(NULL, &sbi->s_es_lru, ext4_inode_touch_time_cmp);
- sbi->s_es_last_sorted = jiffies;
- }
-
+retry:
list_for_each_safe(cur, tmp, &sbi->s_es_lru) {
/*
* If we have already reclaimed all extents from extent
@@ -968,9 +963,16 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
ei = list_entry(cur, struct ext4_inode_info, i_es_lru);
- /* Skip the inode that is newer than the last_sorted time */
- if (sbi->s_es_last_sorted < ei->i_touch_when) {
- list_move_tail(cur, &skiped);
+ /*
+ * Skip the inode that is newer than the last_sorted
+ * time. Normally we try hard to avoid shrinking
+ * precached inodes, but we will as a last resort.
+ */
+ if ((sbi->s_es_last_sorted < ei->i_touch_when) ||
+ (skip_precached && ext4_test_inode_state(&ei->vfs_inode,
+ EXT4_STATE_EXT_PRECACHED))) {
+ nr_skipped++;
+ list_move_tail(cur, &skipped);
continue;
}
@@ -990,11 +992,33 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
}
/* Move the newer inodes into the tail of the LRU list. */
- list_splice_tail(&skiped, &sbi->s_es_lru);
+ list_splice_tail(&skipped, &sbi->s_es_lru);
+ INIT_LIST_HEAD(&skipped);
+
+ /*
+ * If we skipped any inodes, and we weren't able to make any
+ * forward progress, sort the list and try again.
+ */
+ if ((nr_shrunk == 0) && nr_skipped && !retried) {
+ retried++;
+ list_sort(NULL, &sbi->s_es_lru, ext4_inode_touch_time_cmp);
+ sbi->s_es_last_sorted = jiffies;
+ ei = list_first_entry(&sbi->s_es_lru, struct ext4_inode_info,
+ i_es_lru);
+ /*
+ * If there are no non-precached inodes left on the
+ * list, start releasing precached extents.
+ */
+ if (ext4_test_inode_state(&ei->vfs_inode,
+ EXT4_STATE_EXT_PRECACHED))
+ skip_precached = 0;
+ goto retry;
+ }
+
spin_unlock(&sbi->s_es_lru_lock);
if (locked_ei && nr_shrunk == 0)
- nr_shrunk = __es_try_to_reclaim_extents(ei, nr_to_scan);
+ nr_shrunk = __es_try_to_reclaim_extents(locked_ei, nr_to_scan);
return nr_shrunk;
}
@@ -1069,10 +1093,16 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
struct rb_node *node;
struct extent_status *es;
int nr_shrunk = 0;
+ static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
if (ei->i_es_lru_nr == 0)
return 0;
+ if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
+ __ratelimit(&_rs))
+ ext4_warning(inode->i_sb, "forced shrink of precached extents");
+
node = rb_first(&tree->root);
while (node != NULL) {
es = rb_entry(node, struct extent_status, rb_node);
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index c0427e2..5498f75 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -624,6 +624,8 @@ resizefs_out:
return 0;
}
+ case EXT4_IOC_PRECACHE_EXTENTS:
+ return ext4_ext_precache(inode);
default:
return -ENOTTY;
@@ -688,6 +690,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case EXT4_IOC_MOVE_EXT:
case FITRIM:
case EXT4_IOC_RESIZE_FS:
+ case EXT4_IOC_PRECACHE_EXTENTS:
break;
default:
return -ENOIOCTLCMD;