mirror of
https://github.com/torvalds/linux.git
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7ea65c89d8
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZem3wQAKCRCRxhvAZXjc otRMAQDeo8qsuuIAcS2KUicKqZR5yMVvrY9r4sQzf7YRcJo5HQD+NQXkKwQuv1VO OUeScsic/+I+136AgdjWnlEYO5dp0go= =4WKU -----END PGP SIGNATURE----- Merge tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Misc features, cleanups, and fixes for vfs and individual filesystems. Features: - Support idmapped mounts for hugetlbfs. - Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug where the passed offset is ignored if the file is O_APPEND. The new flag allows a caller to enforce that the offset is honored to conform to posix even if the file was opened in append mode. - Move i_mmap_rwsem in struct address_space to avoid false sharing between i_mmap and i_mmap_rwsem. - Convert efs, qnx4, and coda to use the new mount api. - Add a generic is_dot_dotdot() helper that's used by various filesystems and the VFS code instead of open-coding it multiple times. - Recently we've added stable offsets which allows stable ordering when iterating directories exported through NFS on e.g., tmpfs filesystems. Originally an xarray was used for the offset map but that caused slab fragmentation issues over time. This switches the offset map to the maple tree which has a dense mode that handles this scenario a lot better. Includes tests. - Finally merge the case-insensitive improvement series Gabriel has been working on for a long time. This cleanly propagates case insensitive operations through ->s_d_op which in turn allows us to remove the quite ugly generic_set_encrypted_ci_d_ops() operations. It also improves performance by trying a case-sensitive comparison first and then fallback to case-insensitive lookup if that fails. This also fixes a bug where overlayfs would be able to be mounted over a case insensitive directory which would lead to all sort of odd behaviors. Cleanups: - Make file_dentry() a simple accessor now that ->d_real() is simplified because of the backing file work we did the last two cycles. - Use the dedicated file_mnt_idmap helper in ntfs3. - Use smp_load_acquire/store_release() in the i_size_read/write helpers and thus remove the hack to handle i_size reads in the filemap code. - The SLAB_MEM_SPREAD is a nop now. Remove it from various places in fs/ - It's no longer necessary to perform a second built-in initramfs unpack call because we retain the contents of the previous extraction. Remove it. - Now that we have removed various allocators kfree_rcu() always works with kmem caches and kmalloc(). So simplify various places that only use an rcu callback in order to handle the kmem cache case. - Convert the pipe code to use a lockdep comparison function instead of open-coding the nesting making lockdep validation easier. - Move code into fs-writeback.c that was located in a header but can be made static as it's only used in that one file. - Rewrite the alignment checking iterators for iovec and bvec to be easier to read, and also significantly more compact in terms of generated code. This saves 270 bytes of text on x86-64 (with clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also saves a bit of time for the same workload. - Switch various places to use KMEM_CACHE instead of kmem_cache_create(). - Use inode_set_ctime_to_ts() in inode_set_ctime_current() - Use kzalloc() in name_to_handle_at() to avoid kernel infoleak. - Various smaller cleanups for eventfds. Fixes: - Fix various comments and typos, and unneeded initializations. - Fix stack allocation hack for clang in the select code. - Improve dump_mapping() debug code on a best-effort basis. - Fix build errors in various selftests. - Avoid wrap-around instrumentation in various places. - Don't allow user namespaces without an idmapping to be used for idmapped mounts. - Fix sysv sb_read() call. - Fix fallback implementation of the get_name() export operation" * tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits) hugetlbfs: support idmapped mounts qnx4: convert qnx4 to use the new mount api fs: use inode_set_ctime_to_ts to set inode ctime to current time libfs: Drop generic_set_encrypted_ci_d_ops ubifs: Configure dentry operations at dentry-creation time f2fs: Configure dentry operations at dentry-creation time ext4: Configure dentry operations at dentry-creation time libfs: Add helper to choose dentry operations at mount-time libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops fscrypt: Drop d_revalidate once the key is added fscrypt: Drop d_revalidate for valid dentries during lookup fscrypt: Factor out a helper to configure the lookup dentry ovl: Always reject mounting over case-insensitive directories libfs: Attempt exact-match comparison first during casefolded lookup efs: remove SLAB_MEM_SPREAD flag usage jfs: remove SLAB_MEM_SPREAD flag usage minix: remove SLAB_MEM_SPREAD flag usage openpromfs: remove SLAB_MEM_SPREAD flag usage proc: remove SLAB_MEM_SPREAD flag usage qnx6: remove SLAB_MEM_SPREAD flag usage ...
1107 lines
27 KiB
C
1107 lines
27 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/blkdev.h>
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#include <linux/wait.h>
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#include <linux/rbtree.h>
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#include <linux/kthread.h>
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#include <linux/backing-dev.h>
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#include <linux/blk-cgroup.h>
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#include <linux/freezer.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/mm.h>
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#include <linux/sched/mm.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/writeback.h>
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#include <linux/device.h>
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#include <trace/events/writeback.h>
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#include "internal.h"
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struct backing_dev_info noop_backing_dev_info;
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EXPORT_SYMBOL_GPL(noop_backing_dev_info);
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static const char *bdi_unknown_name = "(unknown)";
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/*
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* bdi_lock protects bdi_tree and updates to bdi_list. bdi_list has RCU
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* reader side locking.
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*/
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DEFINE_SPINLOCK(bdi_lock);
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static u64 bdi_id_cursor;
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static struct rb_root bdi_tree = RB_ROOT;
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LIST_HEAD(bdi_list);
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/* bdi_wq serves all asynchronous writeback tasks */
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struct workqueue_struct *bdi_wq;
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#ifdef CONFIG_DEBUG_FS
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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static struct dentry *bdi_debug_root;
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static void bdi_debug_init(void)
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{
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bdi_debug_root = debugfs_create_dir("bdi", NULL);
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}
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static int bdi_debug_stats_show(struct seq_file *m, void *v)
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{
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struct backing_dev_info *bdi = m->private;
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struct bdi_writeback *wb = &bdi->wb;
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unsigned long background_thresh;
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unsigned long dirty_thresh;
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unsigned long wb_thresh;
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unsigned long nr_dirty, nr_io, nr_more_io, nr_dirty_time;
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struct inode *inode;
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nr_dirty = nr_io = nr_more_io = nr_dirty_time = 0;
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spin_lock(&wb->list_lock);
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list_for_each_entry(inode, &wb->b_dirty, i_io_list)
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nr_dirty++;
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list_for_each_entry(inode, &wb->b_io, i_io_list)
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nr_io++;
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list_for_each_entry(inode, &wb->b_more_io, i_io_list)
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nr_more_io++;
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list_for_each_entry(inode, &wb->b_dirty_time, i_io_list)
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if (inode->i_state & I_DIRTY_TIME)
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nr_dirty_time++;
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spin_unlock(&wb->list_lock);
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global_dirty_limits(&background_thresh, &dirty_thresh);
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wb_thresh = wb_calc_thresh(wb, dirty_thresh);
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seq_printf(m,
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"BdiWriteback: %10lu kB\n"
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"BdiReclaimable: %10lu kB\n"
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"BdiDirtyThresh: %10lu kB\n"
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"DirtyThresh: %10lu kB\n"
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"BackgroundThresh: %10lu kB\n"
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"BdiDirtied: %10lu kB\n"
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"BdiWritten: %10lu kB\n"
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"BdiWriteBandwidth: %10lu kBps\n"
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"b_dirty: %10lu\n"
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"b_io: %10lu\n"
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"b_more_io: %10lu\n"
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"b_dirty_time: %10lu\n"
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"bdi_list: %10u\n"
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"state: %10lx\n",
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(unsigned long) K(wb_stat(wb, WB_WRITEBACK)),
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(unsigned long) K(wb_stat(wb, WB_RECLAIMABLE)),
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K(wb_thresh),
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K(dirty_thresh),
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K(background_thresh),
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(unsigned long) K(wb_stat(wb, WB_DIRTIED)),
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(unsigned long) K(wb_stat(wb, WB_WRITTEN)),
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(unsigned long) K(wb->write_bandwidth),
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nr_dirty,
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nr_io,
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nr_more_io,
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nr_dirty_time,
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!list_empty(&bdi->bdi_list), bdi->wb.state);
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return 0;
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}
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DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats);
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static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
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{
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bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
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debugfs_create_file("stats", 0444, bdi->debug_dir, bdi,
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&bdi_debug_stats_fops);
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}
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static void bdi_debug_unregister(struct backing_dev_info *bdi)
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{
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debugfs_remove_recursive(bdi->debug_dir);
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}
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#else
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static inline void bdi_debug_init(void)
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{
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}
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static inline void bdi_debug_register(struct backing_dev_info *bdi,
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const char *name)
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{
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}
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static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
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{
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}
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#endif
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static ssize_t read_ahead_kb_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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unsigned long read_ahead_kb;
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ssize_t ret;
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ret = kstrtoul(buf, 10, &read_ahead_kb);
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if (ret < 0)
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return ret;
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bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
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return count;
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}
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#define BDI_SHOW(name, expr) \
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static ssize_t name##_show(struct device *dev, \
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struct device_attribute *attr, char *buf) \
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{ \
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struct backing_dev_info *bdi = dev_get_drvdata(dev); \
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\
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return sysfs_emit(buf, "%lld\n", (long long)expr); \
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} \
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static DEVICE_ATTR_RW(name);
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BDI_SHOW(read_ahead_kb, K(bdi->ra_pages))
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static ssize_t min_ratio_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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unsigned int ratio;
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ssize_t ret;
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ret = kstrtouint(buf, 10, &ratio);
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if (ret < 0)
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return ret;
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ret = bdi_set_min_ratio(bdi, ratio);
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if (!ret)
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ret = count;
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return ret;
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}
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BDI_SHOW(min_ratio, bdi->min_ratio / BDI_RATIO_SCALE)
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static ssize_t min_ratio_fine_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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unsigned int ratio;
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ssize_t ret;
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ret = kstrtouint(buf, 10, &ratio);
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if (ret < 0)
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return ret;
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ret = bdi_set_min_ratio_no_scale(bdi, ratio);
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if (!ret)
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ret = count;
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return ret;
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}
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BDI_SHOW(min_ratio_fine, bdi->min_ratio)
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static ssize_t max_ratio_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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unsigned int ratio;
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ssize_t ret;
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ret = kstrtouint(buf, 10, &ratio);
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if (ret < 0)
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return ret;
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ret = bdi_set_max_ratio(bdi, ratio);
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if (!ret)
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ret = count;
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return ret;
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}
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BDI_SHOW(max_ratio, bdi->max_ratio / BDI_RATIO_SCALE)
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static ssize_t max_ratio_fine_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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unsigned int ratio;
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ssize_t ret;
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ret = kstrtouint(buf, 10, &ratio);
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if (ret < 0)
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return ret;
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ret = bdi_set_max_ratio_no_scale(bdi, ratio);
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if (!ret)
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ret = count;
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return ret;
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}
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BDI_SHOW(max_ratio_fine, bdi->max_ratio)
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static ssize_t min_bytes_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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return sysfs_emit(buf, "%llu\n", bdi_get_min_bytes(bdi));
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}
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static ssize_t min_bytes_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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u64 bytes;
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ssize_t ret;
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ret = kstrtoull(buf, 10, &bytes);
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if (ret < 0)
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return ret;
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ret = bdi_set_min_bytes(bdi, bytes);
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if (!ret)
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ret = count;
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return ret;
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}
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static DEVICE_ATTR_RW(min_bytes);
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static ssize_t max_bytes_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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return sysfs_emit(buf, "%llu\n", bdi_get_max_bytes(bdi));
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}
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static ssize_t max_bytes_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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u64 bytes;
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ssize_t ret;
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ret = kstrtoull(buf, 10, &bytes);
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if (ret < 0)
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return ret;
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ret = bdi_set_max_bytes(bdi, bytes);
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if (!ret)
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ret = count;
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return ret;
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}
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static DEVICE_ATTR_RW(max_bytes);
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static ssize_t stable_pages_required_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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dev_warn_once(dev,
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"the stable_pages_required attribute has been removed. Use the stable_writes queue attribute instead.\n");
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return sysfs_emit(buf, "%d\n", 0);
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}
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static DEVICE_ATTR_RO(stable_pages_required);
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static ssize_t strict_limit_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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unsigned int strict_limit;
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ssize_t ret;
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ret = kstrtouint(buf, 10, &strict_limit);
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if (ret < 0)
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return ret;
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ret = bdi_set_strict_limit(bdi, strict_limit);
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if (!ret)
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ret = count;
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return ret;
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}
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static ssize_t strict_limit_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct backing_dev_info *bdi = dev_get_drvdata(dev);
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return sysfs_emit(buf, "%d\n",
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!!(bdi->capabilities & BDI_CAP_STRICTLIMIT));
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}
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static DEVICE_ATTR_RW(strict_limit);
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static struct attribute *bdi_dev_attrs[] = {
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&dev_attr_read_ahead_kb.attr,
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&dev_attr_min_ratio.attr,
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&dev_attr_min_ratio_fine.attr,
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&dev_attr_max_ratio.attr,
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&dev_attr_max_ratio_fine.attr,
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&dev_attr_min_bytes.attr,
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&dev_attr_max_bytes.attr,
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&dev_attr_stable_pages_required.attr,
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&dev_attr_strict_limit.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(bdi_dev);
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static const struct class bdi_class = {
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.name = "bdi",
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.dev_groups = bdi_dev_groups,
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};
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static __init int bdi_class_init(void)
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{
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int ret;
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ret = class_register(&bdi_class);
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if (ret)
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return ret;
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bdi_debug_init();
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return 0;
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}
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postcore_initcall(bdi_class_init);
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static int __init default_bdi_init(void)
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{
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bdi_wq = alloc_workqueue("writeback", WQ_MEM_RECLAIM | WQ_UNBOUND |
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WQ_SYSFS, 0);
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if (!bdi_wq)
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return -ENOMEM;
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return 0;
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}
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subsys_initcall(default_bdi_init);
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static void wb_update_bandwidth_workfn(struct work_struct *work)
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{
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struct bdi_writeback *wb = container_of(to_delayed_work(work),
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struct bdi_writeback, bw_dwork);
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wb_update_bandwidth(wb);
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}
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/*
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* Initial write bandwidth: 100 MB/s
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*/
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#define INIT_BW (100 << (20 - PAGE_SHIFT))
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static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
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gfp_t gfp)
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{
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int i, err;
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memset(wb, 0, sizeof(*wb));
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wb->bdi = bdi;
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wb->last_old_flush = jiffies;
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INIT_LIST_HEAD(&wb->b_dirty);
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INIT_LIST_HEAD(&wb->b_io);
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INIT_LIST_HEAD(&wb->b_more_io);
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INIT_LIST_HEAD(&wb->b_dirty_time);
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spin_lock_init(&wb->list_lock);
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atomic_set(&wb->writeback_inodes, 0);
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wb->bw_time_stamp = jiffies;
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wb->balanced_dirty_ratelimit = INIT_BW;
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wb->dirty_ratelimit = INIT_BW;
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wb->write_bandwidth = INIT_BW;
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wb->avg_write_bandwidth = INIT_BW;
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spin_lock_init(&wb->work_lock);
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INIT_LIST_HEAD(&wb->work_list);
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INIT_DELAYED_WORK(&wb->dwork, wb_workfn);
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INIT_DELAYED_WORK(&wb->bw_dwork, wb_update_bandwidth_workfn);
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err = fprop_local_init_percpu(&wb->completions, gfp);
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if (err)
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return err;
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for (i = 0; i < NR_WB_STAT_ITEMS; i++) {
|
|
err = percpu_counter_init(&wb->stat[i], 0, gfp);
|
|
if (err)
|
|
goto out_destroy_stat;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_destroy_stat:
|
|
while (i--)
|
|
percpu_counter_destroy(&wb->stat[i]);
|
|
fprop_local_destroy_percpu(&wb->completions);
|
|
return err;
|
|
}
|
|
|
|
static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb);
|
|
|
|
/*
|
|
* Remove bdi from the global list and shutdown any threads we have running
|
|
*/
|
|
static void wb_shutdown(struct bdi_writeback *wb)
|
|
{
|
|
/* Make sure nobody queues further work */
|
|
spin_lock_irq(&wb->work_lock);
|
|
if (!test_and_clear_bit(WB_registered, &wb->state)) {
|
|
spin_unlock_irq(&wb->work_lock);
|
|
return;
|
|
}
|
|
spin_unlock_irq(&wb->work_lock);
|
|
|
|
cgwb_remove_from_bdi_list(wb);
|
|
/*
|
|
* Drain work list and shutdown the delayed_work. !WB_registered
|
|
* tells wb_workfn() that @wb is dying and its work_list needs to
|
|
* be drained no matter what.
|
|
*/
|
|
mod_delayed_work(bdi_wq, &wb->dwork, 0);
|
|
flush_delayed_work(&wb->dwork);
|
|
WARN_ON(!list_empty(&wb->work_list));
|
|
flush_delayed_work(&wb->bw_dwork);
|
|
}
|
|
|
|
static void wb_exit(struct bdi_writeback *wb)
|
|
{
|
|
int i;
|
|
|
|
WARN_ON(delayed_work_pending(&wb->dwork));
|
|
|
|
for (i = 0; i < NR_WB_STAT_ITEMS; i++)
|
|
percpu_counter_destroy(&wb->stat[i]);
|
|
|
|
fprop_local_destroy_percpu(&wb->completions);
|
|
}
|
|
|
|
#ifdef CONFIG_CGROUP_WRITEBACK
|
|
|
|
#include <linux/memcontrol.h>
|
|
|
|
/*
|
|
* cgwb_lock protects bdi->cgwb_tree, blkcg->cgwb_list, offline_cgwbs and
|
|
* memcg->cgwb_list. bdi->cgwb_tree is also RCU protected.
|
|
*/
|
|
static DEFINE_SPINLOCK(cgwb_lock);
|
|
static struct workqueue_struct *cgwb_release_wq;
|
|
|
|
static LIST_HEAD(offline_cgwbs);
|
|
static void cleanup_offline_cgwbs_workfn(struct work_struct *work);
|
|
static DECLARE_WORK(cleanup_offline_cgwbs_work, cleanup_offline_cgwbs_workfn);
|
|
|
|
static void cgwb_free_rcu(struct rcu_head *rcu_head)
|
|
{
|
|
struct bdi_writeback *wb = container_of(rcu_head,
|
|
struct bdi_writeback, rcu);
|
|
|
|
percpu_ref_exit(&wb->refcnt);
|
|
kfree(wb);
|
|
}
|
|
|
|
static void cgwb_release_workfn(struct work_struct *work)
|
|
{
|
|
struct bdi_writeback *wb = container_of(work, struct bdi_writeback,
|
|
release_work);
|
|
struct backing_dev_info *bdi = wb->bdi;
|
|
|
|
mutex_lock(&wb->bdi->cgwb_release_mutex);
|
|
wb_shutdown(wb);
|
|
|
|
css_put(wb->memcg_css);
|
|
css_put(wb->blkcg_css);
|
|
mutex_unlock(&wb->bdi->cgwb_release_mutex);
|
|
|
|
/* triggers blkg destruction if no online users left */
|
|
blkcg_unpin_online(wb->blkcg_css);
|
|
|
|
fprop_local_destroy_percpu(&wb->memcg_completions);
|
|
|
|
spin_lock_irq(&cgwb_lock);
|
|
list_del(&wb->offline_node);
|
|
spin_unlock_irq(&cgwb_lock);
|
|
|
|
wb_exit(wb);
|
|
bdi_put(bdi);
|
|
WARN_ON_ONCE(!list_empty(&wb->b_attached));
|
|
call_rcu(&wb->rcu, cgwb_free_rcu);
|
|
}
|
|
|
|
static void cgwb_release(struct percpu_ref *refcnt)
|
|
{
|
|
struct bdi_writeback *wb = container_of(refcnt, struct bdi_writeback,
|
|
refcnt);
|
|
queue_work(cgwb_release_wq, &wb->release_work);
|
|
}
|
|
|
|
static void cgwb_kill(struct bdi_writeback *wb)
|
|
{
|
|
lockdep_assert_held(&cgwb_lock);
|
|
|
|
WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id));
|
|
list_del(&wb->memcg_node);
|
|
list_del(&wb->blkcg_node);
|
|
list_add(&wb->offline_node, &offline_cgwbs);
|
|
percpu_ref_kill(&wb->refcnt);
|
|
}
|
|
|
|
static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb)
|
|
{
|
|
spin_lock_irq(&cgwb_lock);
|
|
list_del_rcu(&wb->bdi_node);
|
|
spin_unlock_irq(&cgwb_lock);
|
|
}
|
|
|
|
static int cgwb_create(struct backing_dev_info *bdi,
|
|
struct cgroup_subsys_state *memcg_css, gfp_t gfp)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct cgroup_subsys_state *blkcg_css;
|
|
struct list_head *memcg_cgwb_list, *blkcg_cgwb_list;
|
|
struct bdi_writeback *wb;
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
memcg = mem_cgroup_from_css(memcg_css);
|
|
blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
|
|
memcg_cgwb_list = &memcg->cgwb_list;
|
|
blkcg_cgwb_list = blkcg_get_cgwb_list(blkcg_css);
|
|
|
|
/* look up again under lock and discard on blkcg mismatch */
|
|
spin_lock_irqsave(&cgwb_lock, flags);
|
|
wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
|
|
if (wb && wb->blkcg_css != blkcg_css) {
|
|
cgwb_kill(wb);
|
|
wb = NULL;
|
|
}
|
|
spin_unlock_irqrestore(&cgwb_lock, flags);
|
|
if (wb)
|
|
goto out_put;
|
|
|
|
/* need to create a new one */
|
|
wb = kmalloc(sizeof(*wb), gfp);
|
|
if (!wb) {
|
|
ret = -ENOMEM;
|
|
goto out_put;
|
|
}
|
|
|
|
ret = wb_init(wb, bdi, gfp);
|
|
if (ret)
|
|
goto err_free;
|
|
|
|
ret = percpu_ref_init(&wb->refcnt, cgwb_release, 0, gfp);
|
|
if (ret)
|
|
goto err_wb_exit;
|
|
|
|
ret = fprop_local_init_percpu(&wb->memcg_completions, gfp);
|
|
if (ret)
|
|
goto err_ref_exit;
|
|
|
|
wb->memcg_css = memcg_css;
|
|
wb->blkcg_css = blkcg_css;
|
|
INIT_LIST_HEAD(&wb->b_attached);
|
|
INIT_WORK(&wb->release_work, cgwb_release_workfn);
|
|
set_bit(WB_registered, &wb->state);
|
|
bdi_get(bdi);
|
|
|
|
/*
|
|
* The root wb determines the registered state of the whole bdi and
|
|
* memcg_cgwb_list and blkcg_cgwb_list's next pointers indicate
|
|
* whether they're still online. Don't link @wb if any is dead.
|
|
* See wb_memcg_offline() and wb_blkcg_offline().
|
|
*/
|
|
ret = -ENODEV;
|
|
spin_lock_irqsave(&cgwb_lock, flags);
|
|
if (test_bit(WB_registered, &bdi->wb.state) &&
|
|
blkcg_cgwb_list->next && memcg_cgwb_list->next) {
|
|
/* we might have raced another instance of this function */
|
|
ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb);
|
|
if (!ret) {
|
|
list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
|
|
list_add(&wb->memcg_node, memcg_cgwb_list);
|
|
list_add(&wb->blkcg_node, blkcg_cgwb_list);
|
|
blkcg_pin_online(blkcg_css);
|
|
css_get(memcg_css);
|
|
css_get(blkcg_css);
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&cgwb_lock, flags);
|
|
if (ret) {
|
|
if (ret == -EEXIST)
|
|
ret = 0;
|
|
goto err_fprop_exit;
|
|
}
|
|
goto out_put;
|
|
|
|
err_fprop_exit:
|
|
bdi_put(bdi);
|
|
fprop_local_destroy_percpu(&wb->memcg_completions);
|
|
err_ref_exit:
|
|
percpu_ref_exit(&wb->refcnt);
|
|
err_wb_exit:
|
|
wb_exit(wb);
|
|
err_free:
|
|
kfree(wb);
|
|
out_put:
|
|
css_put(blkcg_css);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* wb_get_lookup - get wb for a given memcg
|
|
* @bdi: target bdi
|
|
* @memcg_css: cgroup_subsys_state of the target memcg (must have positive ref)
|
|
*
|
|
* Try to get the wb for @memcg_css on @bdi. The returned wb has its
|
|
* refcount incremented.
|
|
*
|
|
* This function uses css_get() on @memcg_css and thus expects its refcnt
|
|
* to be positive on invocation. IOW, rcu_read_lock() protection on
|
|
* @memcg_css isn't enough. try_get it before calling this function.
|
|
*
|
|
* A wb is keyed by its associated memcg. As blkcg implicitly enables
|
|
* memcg on the default hierarchy, memcg association is guaranteed to be
|
|
* more specific (equal or descendant to the associated blkcg) and thus can
|
|
* identify both the memcg and blkcg associations.
|
|
*
|
|
* Because the blkcg associated with a memcg may change as blkcg is enabled
|
|
* and disabled closer to root in the hierarchy, each wb keeps track of
|
|
* both the memcg and blkcg associated with it and verifies the blkcg on
|
|
* each lookup. On mismatch, the existing wb is discarded and a new one is
|
|
* created.
|
|
*/
|
|
struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi,
|
|
struct cgroup_subsys_state *memcg_css)
|
|
{
|
|
struct bdi_writeback *wb;
|
|
|
|
if (!memcg_css->parent)
|
|
return &bdi->wb;
|
|
|
|
rcu_read_lock();
|
|
wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
|
|
if (wb) {
|
|
struct cgroup_subsys_state *blkcg_css;
|
|
|
|
/* see whether the blkcg association has changed */
|
|
blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
|
|
if (unlikely(wb->blkcg_css != blkcg_css || !wb_tryget(wb)))
|
|
wb = NULL;
|
|
css_put(blkcg_css);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return wb;
|
|
}
|
|
|
|
/**
|
|
* wb_get_create - get wb for a given memcg, create if necessary
|
|
* @bdi: target bdi
|
|
* @memcg_css: cgroup_subsys_state of the target memcg (must have positive ref)
|
|
* @gfp: allocation mask to use
|
|
*
|
|
* Try to get the wb for @memcg_css on @bdi. If it doesn't exist, try to
|
|
* create one. See wb_get_lookup() for more details.
|
|
*/
|
|
struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
|
|
struct cgroup_subsys_state *memcg_css,
|
|
gfp_t gfp)
|
|
{
|
|
struct bdi_writeback *wb;
|
|
|
|
might_alloc(gfp);
|
|
|
|
do {
|
|
wb = wb_get_lookup(bdi, memcg_css);
|
|
} while (!wb && !cgwb_create(bdi, memcg_css, gfp));
|
|
|
|
return wb;
|
|
}
|
|
|
|
static int cgwb_bdi_init(struct backing_dev_info *bdi)
|
|
{
|
|
int ret;
|
|
|
|
INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC);
|
|
mutex_init(&bdi->cgwb_release_mutex);
|
|
init_rwsem(&bdi->wb_switch_rwsem);
|
|
|
|
ret = wb_init(&bdi->wb, bdi, GFP_KERNEL);
|
|
if (!ret) {
|
|
bdi->wb.memcg_css = &root_mem_cgroup->css;
|
|
bdi->wb.blkcg_css = blkcg_root_css;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
|
|
{
|
|
struct radix_tree_iter iter;
|
|
void **slot;
|
|
struct bdi_writeback *wb;
|
|
|
|
WARN_ON(test_bit(WB_registered, &bdi->wb.state));
|
|
|
|
spin_lock_irq(&cgwb_lock);
|
|
radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0)
|
|
cgwb_kill(*slot);
|
|
spin_unlock_irq(&cgwb_lock);
|
|
|
|
mutex_lock(&bdi->cgwb_release_mutex);
|
|
spin_lock_irq(&cgwb_lock);
|
|
while (!list_empty(&bdi->wb_list)) {
|
|
wb = list_first_entry(&bdi->wb_list, struct bdi_writeback,
|
|
bdi_node);
|
|
spin_unlock_irq(&cgwb_lock);
|
|
wb_shutdown(wb);
|
|
spin_lock_irq(&cgwb_lock);
|
|
}
|
|
spin_unlock_irq(&cgwb_lock);
|
|
mutex_unlock(&bdi->cgwb_release_mutex);
|
|
}
|
|
|
|
/*
|
|
* cleanup_offline_cgwbs_workfn - try to release dying cgwbs
|
|
*
|
|
* Try to release dying cgwbs by switching attached inodes to the nearest
|
|
* living ancestor's writeback. Processed wbs are placed at the end
|
|
* of the list to guarantee the forward progress.
|
|
*/
|
|
static void cleanup_offline_cgwbs_workfn(struct work_struct *work)
|
|
{
|
|
struct bdi_writeback *wb;
|
|
LIST_HEAD(processed);
|
|
|
|
spin_lock_irq(&cgwb_lock);
|
|
|
|
while (!list_empty(&offline_cgwbs)) {
|
|
wb = list_first_entry(&offline_cgwbs, struct bdi_writeback,
|
|
offline_node);
|
|
list_move(&wb->offline_node, &processed);
|
|
|
|
/*
|
|
* If wb is dirty, cleaning up the writeback by switching
|
|
* attached inodes will result in an effective removal of any
|
|
* bandwidth restrictions, which isn't the goal. Instead,
|
|
* it can be postponed until the next time, when all io
|
|
* will be likely completed. If in the meantime some inodes
|
|
* will get re-dirtied, they should be eventually switched to
|
|
* a new cgwb.
|
|
*/
|
|
if (wb_has_dirty_io(wb))
|
|
continue;
|
|
|
|
if (!wb_tryget(wb))
|
|
continue;
|
|
|
|
spin_unlock_irq(&cgwb_lock);
|
|
while (cleanup_offline_cgwb(wb))
|
|
cond_resched();
|
|
spin_lock_irq(&cgwb_lock);
|
|
|
|
wb_put(wb);
|
|
}
|
|
|
|
if (!list_empty(&processed))
|
|
list_splice_tail(&processed, &offline_cgwbs);
|
|
|
|
spin_unlock_irq(&cgwb_lock);
|
|
}
|
|
|
|
/**
|
|
* wb_memcg_offline - kill all wb's associated with a memcg being offlined
|
|
* @memcg: memcg being offlined
|
|
*
|
|
* Also prevents creation of any new wb's associated with @memcg.
|
|
*/
|
|
void wb_memcg_offline(struct mem_cgroup *memcg)
|
|
{
|
|
struct list_head *memcg_cgwb_list = &memcg->cgwb_list;
|
|
struct bdi_writeback *wb, *next;
|
|
|
|
spin_lock_irq(&cgwb_lock);
|
|
list_for_each_entry_safe(wb, next, memcg_cgwb_list, memcg_node)
|
|
cgwb_kill(wb);
|
|
memcg_cgwb_list->next = NULL; /* prevent new wb's */
|
|
spin_unlock_irq(&cgwb_lock);
|
|
|
|
queue_work(system_unbound_wq, &cleanup_offline_cgwbs_work);
|
|
}
|
|
|
|
/**
|
|
* wb_blkcg_offline - kill all wb's associated with a blkcg being offlined
|
|
* @css: blkcg being offlined
|
|
*
|
|
* Also prevents creation of any new wb's associated with @blkcg.
|
|
*/
|
|
void wb_blkcg_offline(struct cgroup_subsys_state *css)
|
|
{
|
|
struct bdi_writeback *wb, *next;
|
|
struct list_head *list = blkcg_get_cgwb_list(css);
|
|
|
|
spin_lock_irq(&cgwb_lock);
|
|
list_for_each_entry_safe(wb, next, list, blkcg_node)
|
|
cgwb_kill(wb);
|
|
list->next = NULL; /* prevent new wb's */
|
|
spin_unlock_irq(&cgwb_lock);
|
|
}
|
|
|
|
static void cgwb_bdi_register(struct backing_dev_info *bdi)
|
|
{
|
|
spin_lock_irq(&cgwb_lock);
|
|
list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
|
|
spin_unlock_irq(&cgwb_lock);
|
|
}
|
|
|
|
static int __init cgwb_init(void)
|
|
{
|
|
/*
|
|
* There can be many concurrent release work items overwhelming
|
|
* system_wq. Put them in a separate wq and limit concurrency.
|
|
* There's no point in executing many of these in parallel.
|
|
*/
|
|
cgwb_release_wq = alloc_workqueue("cgwb_release", 0, 1);
|
|
if (!cgwb_release_wq)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
subsys_initcall(cgwb_init);
|
|
|
|
#else /* CONFIG_CGROUP_WRITEBACK */
|
|
|
|
static int cgwb_bdi_init(struct backing_dev_info *bdi)
|
|
{
|
|
return wb_init(&bdi->wb, bdi, GFP_KERNEL);
|
|
}
|
|
|
|
static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { }
|
|
|
|
static void cgwb_bdi_register(struct backing_dev_info *bdi)
|
|
{
|
|
list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
|
|
}
|
|
|
|
static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb)
|
|
{
|
|
list_del_rcu(&wb->bdi_node);
|
|
}
|
|
|
|
#endif /* CONFIG_CGROUP_WRITEBACK */
|
|
|
|
int bdi_init(struct backing_dev_info *bdi)
|
|
{
|
|
bdi->dev = NULL;
|
|
|
|
kref_init(&bdi->refcnt);
|
|
bdi->min_ratio = 0;
|
|
bdi->max_ratio = 100 * BDI_RATIO_SCALE;
|
|
bdi->max_prop_frac = FPROP_FRAC_BASE;
|
|
INIT_LIST_HEAD(&bdi->bdi_list);
|
|
INIT_LIST_HEAD(&bdi->wb_list);
|
|
init_waitqueue_head(&bdi->wb_waitq);
|
|
bdi->last_bdp_sleep = jiffies;
|
|
|
|
return cgwb_bdi_init(bdi);
|
|
}
|
|
|
|
struct backing_dev_info *bdi_alloc(int node_id)
|
|
{
|
|
struct backing_dev_info *bdi;
|
|
|
|
bdi = kzalloc_node(sizeof(*bdi), GFP_KERNEL, node_id);
|
|
if (!bdi)
|
|
return NULL;
|
|
|
|
if (bdi_init(bdi)) {
|
|
kfree(bdi);
|
|
return NULL;
|
|
}
|
|
bdi->capabilities = BDI_CAP_WRITEBACK | BDI_CAP_WRITEBACK_ACCT;
|
|
bdi->ra_pages = VM_READAHEAD_PAGES;
|
|
bdi->io_pages = VM_READAHEAD_PAGES;
|
|
timer_setup(&bdi->laptop_mode_wb_timer, laptop_mode_timer_fn, 0);
|
|
return bdi;
|
|
}
|
|
EXPORT_SYMBOL(bdi_alloc);
|
|
|
|
static struct rb_node **bdi_lookup_rb_node(u64 id, struct rb_node **parentp)
|
|
{
|
|
struct rb_node **p = &bdi_tree.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct backing_dev_info *bdi;
|
|
|
|
lockdep_assert_held(&bdi_lock);
|
|
|
|
while (*p) {
|
|
parent = *p;
|
|
bdi = rb_entry(parent, struct backing_dev_info, rb_node);
|
|
|
|
if (bdi->id > id)
|
|
p = &(*p)->rb_left;
|
|
else if (bdi->id < id)
|
|
p = &(*p)->rb_right;
|
|
else
|
|
break;
|
|
}
|
|
|
|
if (parentp)
|
|
*parentp = parent;
|
|
return p;
|
|
}
|
|
|
|
/**
|
|
* bdi_get_by_id - lookup and get bdi from its id
|
|
* @id: bdi id to lookup
|
|
*
|
|
* Find bdi matching @id and get it. Returns NULL if the matching bdi
|
|
* doesn't exist or is already unregistered.
|
|
*/
|
|
struct backing_dev_info *bdi_get_by_id(u64 id)
|
|
{
|
|
struct backing_dev_info *bdi = NULL;
|
|
struct rb_node **p;
|
|
|
|
spin_lock_bh(&bdi_lock);
|
|
p = bdi_lookup_rb_node(id, NULL);
|
|
if (*p) {
|
|
bdi = rb_entry(*p, struct backing_dev_info, rb_node);
|
|
bdi_get(bdi);
|
|
}
|
|
spin_unlock_bh(&bdi_lock);
|
|
|
|
return bdi;
|
|
}
|
|
|
|
int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args)
|
|
{
|
|
struct device *dev;
|
|
struct rb_node *parent, **p;
|
|
|
|
if (bdi->dev) /* The driver needs to use separate queues per device */
|
|
return 0;
|
|
|
|
vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args);
|
|
dev = device_create(&bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name);
|
|
if (IS_ERR(dev))
|
|
return PTR_ERR(dev);
|
|
|
|
cgwb_bdi_register(bdi);
|
|
bdi->dev = dev;
|
|
|
|
bdi_debug_register(bdi, dev_name(dev));
|
|
set_bit(WB_registered, &bdi->wb.state);
|
|
|
|
spin_lock_bh(&bdi_lock);
|
|
|
|
bdi->id = ++bdi_id_cursor;
|
|
|
|
p = bdi_lookup_rb_node(bdi->id, &parent);
|
|
rb_link_node(&bdi->rb_node, parent, p);
|
|
rb_insert_color(&bdi->rb_node, &bdi_tree);
|
|
|
|
list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
|
|
|
|
spin_unlock_bh(&bdi_lock);
|
|
|
|
trace_writeback_bdi_register(bdi);
|
|
return 0;
|
|
}
|
|
|
|
int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
int ret;
|
|
|
|
va_start(args, fmt);
|
|
ret = bdi_register_va(bdi, fmt, args);
|
|
va_end(args);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(bdi_register);
|
|
|
|
void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner)
|
|
{
|
|
WARN_ON_ONCE(bdi->owner);
|
|
bdi->owner = owner;
|
|
get_device(owner);
|
|
}
|
|
|
|
/*
|
|
* Remove bdi from bdi_list, and ensure that it is no longer visible
|
|
*/
|
|
static void bdi_remove_from_list(struct backing_dev_info *bdi)
|
|
{
|
|
spin_lock_bh(&bdi_lock);
|
|
rb_erase(&bdi->rb_node, &bdi_tree);
|
|
list_del_rcu(&bdi->bdi_list);
|
|
spin_unlock_bh(&bdi_lock);
|
|
|
|
synchronize_rcu_expedited();
|
|
}
|
|
|
|
void bdi_unregister(struct backing_dev_info *bdi)
|
|
{
|
|
del_timer_sync(&bdi->laptop_mode_wb_timer);
|
|
|
|
/* make sure nobody finds us on the bdi_list anymore */
|
|
bdi_remove_from_list(bdi);
|
|
wb_shutdown(&bdi->wb);
|
|
cgwb_bdi_unregister(bdi);
|
|
|
|
/*
|
|
* If this BDI's min ratio has been set, use bdi_set_min_ratio() to
|
|
* update the global bdi_min_ratio.
|
|
*/
|
|
if (bdi->min_ratio)
|
|
bdi_set_min_ratio(bdi, 0);
|
|
|
|
if (bdi->dev) {
|
|
bdi_debug_unregister(bdi);
|
|
device_unregister(bdi->dev);
|
|
bdi->dev = NULL;
|
|
}
|
|
|
|
if (bdi->owner) {
|
|
put_device(bdi->owner);
|
|
bdi->owner = NULL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(bdi_unregister);
|
|
|
|
static void release_bdi(struct kref *ref)
|
|
{
|
|
struct backing_dev_info *bdi =
|
|
container_of(ref, struct backing_dev_info, refcnt);
|
|
|
|
WARN_ON_ONCE(test_bit(WB_registered, &bdi->wb.state));
|
|
WARN_ON_ONCE(bdi->dev);
|
|
wb_exit(&bdi->wb);
|
|
kfree(bdi);
|
|
}
|
|
|
|
void bdi_put(struct backing_dev_info *bdi)
|
|
{
|
|
kref_put(&bdi->refcnt, release_bdi);
|
|
}
|
|
EXPORT_SYMBOL(bdi_put);
|
|
|
|
struct backing_dev_info *inode_to_bdi(struct inode *inode)
|
|
{
|
|
struct super_block *sb;
|
|
|
|
if (!inode)
|
|
return &noop_backing_dev_info;
|
|
|
|
sb = inode->i_sb;
|
|
#ifdef CONFIG_BLOCK
|
|
if (sb_is_blkdev_sb(sb))
|
|
return I_BDEV(inode)->bd_disk->bdi;
|
|
#endif
|
|
return sb->s_bdi;
|
|
}
|
|
EXPORT_SYMBOL(inode_to_bdi);
|
|
|
|
const char *bdi_dev_name(struct backing_dev_info *bdi)
|
|
{
|
|
if (!bdi || !bdi->dev)
|
|
return bdi_unknown_name;
|
|
return bdi->dev_name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bdi_dev_name);
|