diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/super.c | 102 |
1 files changed, 40 insertions, 62 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index c64d07134122..7dfe5005129a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -28,7 +28,6 @@ #include <linux/btrfs.h> #include <linux/security.h> #include <linux/fs_parser.h> -#include <linux/swap.h> #include "messages.h" #include "delayed-inode.h" #include "ctree.h" @@ -946,8 +945,7 @@ static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objec } static int btrfs_fill_super(struct super_block *sb, - struct btrfs_fs_devices *fs_devices, - void *data) + struct btrfs_fs_devices *fs_devices) { struct inode *inode; struct btrfs_fs_info *fs_info = btrfs_sb(sb); @@ -971,7 +969,7 @@ static int btrfs_fill_super(struct super_block *sb, return err; } - err = open_ctree(sb, fs_devices, (char *)data); + err = open_ctree(sb, fs_devices); if (err) { btrfs_err(fs_info, "open_ctree failed"); return err; @@ -1887,18 +1885,21 @@ static int btrfs_get_tree_super(struct fs_context *fc) if (sb->s_root) { btrfs_close_devices(fs_devices); - if ((fc->sb_flags ^ sb->s_flags) & SB_RDONLY) - ret = -EBUSY; + /* + * At this stage we may have RO flag mismatch between + * fc->sb_flags and sb->s_flags. Caller should detect such + * mismatch and reconfigure with sb->s_umount rwsem held if + * needed. + */ } else { snprintf(sb->s_id, sizeof(sb->s_id), "%pg", bdev); shrinker_debugfs_rename(sb->s_shrink, "sb-btrfs:%s", sb->s_id); btrfs_sb(sb)->bdev_holder = &btrfs_fs_type; - ret = btrfs_fill_super(sb, fs_devices, NULL); - } - - if (ret) { - deactivate_locked_super(sb); - return ret; + ret = btrfs_fill_super(sb, fs_devices); + if (ret) { + deactivate_locked_super(sb); + return ret; + } } btrfs_clear_oneshot_options(fs_info); @@ -1984,39 +1985,18 @@ error: * btrfs or not, setting the whole super block RO. To make per-subvolume mounting * work with different options work we need to keep backward compatibility. */ -static struct vfsmount *btrfs_reconfigure_for_mount(struct fs_context *fc) +static int btrfs_reconfigure_for_mount(struct fs_context *fc, struct vfsmount *mnt) { - struct vfsmount *mnt; - int ret; - const bool ro2rw = !(fc->sb_flags & SB_RDONLY); - - /* - * We got an EBUSY because our SB_RDONLY flag didn't match the existing - * super block, so invert our setting here and retry the mount so we - * can get our vfsmount. - */ - if (ro2rw) - fc->sb_flags |= SB_RDONLY; - else - fc->sb_flags &= ~SB_RDONLY; - - mnt = fc_mount(fc); - if (IS_ERR(mnt)) - return mnt; + int ret = 0; - if (!ro2rw) - return mnt; + if (fc->sb_flags & SB_RDONLY) + return ret; - /* We need to convert to rw, call reconfigure. */ - fc->sb_flags &= ~SB_RDONLY; down_write(&mnt->mnt_sb->s_umount); - ret = btrfs_reconfigure(fc); + if (!(fc->sb_flags & SB_RDONLY) && (mnt->mnt_sb->s_flags & SB_RDONLY)) + ret = btrfs_reconfigure(fc); up_write(&mnt->mnt_sb->s_umount); - if (ret) { - mntput(mnt); - return ERR_PTR(ret); - } - return mnt; + return ret; } static int btrfs_get_tree_subvol(struct fs_context *fc) @@ -2026,6 +2006,7 @@ static int btrfs_get_tree_subvol(struct fs_context *fc) struct fs_context *dup_fc; struct dentry *dentry; struct vfsmount *mnt; + int ret = 0; /* * Setup a dummy root and fs_info for test/set super. This is because @@ -2068,11 +2049,16 @@ static int btrfs_get_tree_subvol(struct fs_context *fc) fc->security = NULL; mnt = fc_mount(dup_fc); - if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) - mnt = btrfs_reconfigure_for_mount(dup_fc); - put_fs_context(dup_fc); - if (IS_ERR(mnt)) + if (IS_ERR(mnt)) { + put_fs_context(dup_fc); return PTR_ERR(mnt); + } + ret = btrfs_reconfigure_for_mount(dup_fc, mnt); + put_fs_context(dup_fc); + if (ret) { + mntput(mnt); + return ret; + } /* * This free's ->subvol_name, because if it isn't set we have to @@ -2191,7 +2177,8 @@ static struct file_system_type btrfs_fs_type = { .init_fs_context = btrfs_init_fs_context, .parameters = btrfs_fs_parameters, .kill_sb = btrfs_kill_super, - .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP, + .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | + FS_ALLOW_IDMAP | FS_MGTIME, }; MODULE_ALIAS_FS("btrfs"); @@ -2256,7 +2243,10 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false); if (IS_ERR_OR_NULL(device)) { mutex_unlock(&uuid_mutex); - ret = PTR_ERR(device); + if (IS_ERR(device)) + ret = PTR_ERR(device); + else + ret = 0; break; } ret = !(device->fs_devices->num_devices == @@ -2395,13 +2385,7 @@ static long btrfs_nr_cached_objects(struct super_block *sb, struct shrink_contro trace_btrfs_extent_map_shrinker_count(fs_info, nr); - /* - * Only report the real number for DEBUG builds, as there are reports of - * serious performance degradation caused by too frequent shrinks. - */ - if (IS_ENABLED(CONFIG_BTRFS_DEBUG)) - return nr; - return 0; + return nr; } static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_control *sc) @@ -2409,16 +2393,10 @@ static long btrfs_free_cached_objects(struct super_block *sb, struct shrink_cont const long nr_to_scan = min_t(unsigned long, LONG_MAX, sc->nr_to_scan); struct btrfs_fs_info *fs_info = btrfs_sb(sb); - /* - * We may be called from any task trying to allocate memory and we don't - * want to slow it down with scanning and dropping extent maps. It would - * also cause heavy lock contention if many tasks concurrently enter - * here. Therefore only allow kswapd tasks to scan and drop extent maps. - */ - if (!current_is_kswapd()) - return 0; + btrfs_free_extent_maps(fs_info, nr_to_scan); - return btrfs_free_extent_maps(fs_info, nr_to_scan); + /* The extent map shrinker runs asynchronously, so always return 0. */ + return 0; } static const struct super_operations btrfs_super_ops = { |