1 files changed, 67 insertions, 51 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 24b776c08d99..0e92e5763005 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -52,6 +52,7 @@
 #include "locking.h"
 #include "inode-map.h"
 #include "backref.h"
+#include "rcu-string.h"
 
 /* Mask out flags that are inappropriate for the given type of inode. */
 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
@@ -785,39 +786,57 @@ none:
         return -ENOENT;
 }
 
-/*
- * Validaty check of prev em and next em:
- * 1) no prev/next em
- * 2) prev/next em is an hole/inline extent
- */
-static int check_adjacent_extents(struct inode *inode, struct extent_map *em)
+static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 {
         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
-        struct extent_map *prev = NULL, *next = NULL;
-        int ret = 0;
+        struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+        struct extent_map *em;
+        u64 len = PAGE_CACHE_SIZE;
 
+        /*
+         * hopefully we have this extent in the tree already, try without
+         * the full extent lock
+         */
         read_lock(&em_tree->lock);
-        prev = lookup_extent_mapping(em_tree, em->start - 1, (u64)-1);
-        next = lookup_extent_mapping(em_tree, em->start + em->len, (u64)-1);
+        em = lookup_extent_mapping(em_tree, start, len);
         read_unlock(&em_tree->lock);
 
-        if ((!prev || prev->block_start >= EXTENT_MAP_LAST_BYTE) &&
-            (!next || next->block_start >= EXTENT_MAP_LAST_BYTE))
-                ret = 1;
-        free_extent_map(prev);
-        free_extent_map(next);
+        if (!em) {
+                /* get the big lock and read metadata off disk */
+                lock_extent(io_tree, start, start + len - 1);
+                em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
+                unlock_extent(io_tree, start, start + len - 1);
+
+                if (IS_ERR(em))
+                        return NULL;
+        }
+
+        return em;
+}
+
+static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
+{
+        struct extent_map *next;
+        bool ret = true;
 
+        /* this is the last extent */
+        if (em->start + em->len >= i_size_read(inode))
+                return false;
+
+        next = defrag_lookup_extent(inode, em->start + em->len);
+        if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
+                ret = false;
+
+        free_extent_map(next);
         return ret;
 }
 
-static int should_defrag_range(struct inode *inode, u64 start, u64 len,
-                               int thresh, u64 *last_len, u64 *skip,
-                               u64 *defrag_end)
+static int should_defrag_range(struct inode *inode, u64 start, int thresh,
+                               u64 *last_len, u64 *skip, u64 *defrag_end)
 {
-        struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
-        struct extent_map *em = NULL;
-        struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+        struct extent_map *em;
         int ret = 1;
+        bool next_mergeable = true;
 
         /*
          * make sure that once we start defragging an extent, we keep on
@@ -828,23 +847,9 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 
         *skip = 0;
 
-        /*
-         * hopefully we have this extent in the tree already, try without
-         * the full extent lock
-         */
-        read_lock(&em_tree->lock);
-        em = lookup_extent_mapping(em_tree, start, len);
-        read_unlock(&em_tree->lock);
-
-        if (!em) {
-                /* get the big lock and read metadata off disk */
-                lock_extent(io_tree, start, start + len - 1);
-                em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
-                unlock_extent(io_tree, start, start + len - 1);
-
-                if (IS_ERR(em))
-                        return 0;
-        }
+        em = defrag_lookup_extent(inode, start);
+        if (!em)
+                return 0;
 
         /* this will cover holes, and inline extents */
         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
@@ -852,18 +857,15 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
                 goto out;
         }
 
-        /* If we have nothing to merge with us, just skip. */
-        if (check_adjacent_extents(inode, em)) {
-                ret = 0;
-                goto out;
-        }
+        next_mergeable = defrag_check_next_extent(inode, em);
 
         /*
-         * we hit a real extent, if it is big don't bother defragging it again
+         * we hit a real extent, if it is big or the next extent is not a
+         * real extent, don't bother defragging it
          */
-        if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
+        if ((*last_len == 0 || *last_len >= thresh) &&
+            (em->len >= thresh || !next_mergeable))
                 ret = 0;
-
 out:
         /*
          * last_len ends up being a counter of how many bytes we've defragged.
@@ -1142,8 +1144,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
                         break;
 
                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
-                                         PAGE_CACHE_SIZE, extent_thresh,
-                                         &last_len, &skip, &defrag_end)) {
+                                         extent_thresh, &last_len, &skip,
+                                         &defrag_end)) {
                         unsigned long next;
                         /*
                          * the should_defrag function tells us how much to skip
@@ -1304,6 +1306,14 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
                 ret = -EINVAL;
                 goto out_free;
         }
+        if (device->fs_devices && device->fs_devices->seeding) {
+                printk(KERN_INFO "btrfs: resizer unable to apply on "
+                       "seeding device %llu\n",
+                       (unsigned long long)devid);
+                ret = -EINVAL;
+                goto out_free;
+        }
+
         if (!strcmp(sizestr, "max"))
                 new_size = device->bdev->bd_inode->i_size;
         else {
@@ -1345,8 +1355,9 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
         do_div(new_size, root->sectorsize);
         new_size *= root->sectorsize;
 
-        printk(KERN_INFO "btrfs: new size for %s is %llu\n",
-                device->name, (unsigned long long)new_size);
+        printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
+                      rcu_str_deref(device->name),
+                      (unsigned long long)new_size);
 
         if (new_size > old_size) {
                 trans = btrfs_start_transaction(root, 0);
@@ -2264,7 +2275,12 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
         di_args->total_bytes = dev->total_bytes;
         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
         if (dev->name) {
-                strncpy(di_args->path, dev->name, sizeof(di_args->path));
+                struct rcu_string *name;
+
+                rcu_read_lock();
+                name = rcu_dereference(dev->name);
+                strncpy(di_args->path, name->str, sizeof(di_args->path));
+                rcu_read_unlock();
                 di_args->path[sizeof(di_args->path) - 1] = 0;
         } else {
                 di_args->path[0] = '\0';