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authorWolfram Sang <wsa+renesas@sang-engineering.com>2025-05-23 17:18:16 +0200
committerWolfram Sang <wsa+renesas@sang-engineering.com>2025-05-23 17:18:16 +0200
commit9c7dcf4c16ef521657450a82dc26775d6f556209 (patch)
tree1b230b5520ed028e615032a64e8d2bbb088897ec /fs/buffer.c
parent17a3a30e8e3df77d1d1f5bc705b903604a1eedc9 (diff)
parent2b2805404c926b8dcd5c5c13d240722da714906e (diff)
downloadnet-9c7dcf4c16ef521657450a82dc26775d6f556209.tar.gz
Merge tag 'i2c-host-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-mergewindow
i2c-host updates for v6.16 Cleanups and refactorings - Many drivers switched to dev_err_probe() - Generic cleanups applied to designware, iproc, ismt, mlxbf, npcm7xx, qcom-geni, pasemi, and thunderx - davinci: declare I2C mangling support among I2C features - designware: clean up DTS handling - designware: fix PM runtime on driver unregister - imx: improve error logging during probe - lpc2k: improve checks in probe error path - xgene-slimpro: improve PCC shared memory handling - pasemi: improve error handling in reset, smbus clear, timeouts - tegra: validate buffer length during transfers - wmt: convert binding to YAML format Improvements and extended support: - microchip-core: add SMBus support - mlxbf: add support for repeated start in block transfers - mlxbf: improve timer configuration - npcm: attempt clock toggle recovery before failing init - octeon: add support for block mode operations - pasemi: add support for unjam device feature - riic: add support for bus recovery New device support: - MediaTek Dimensity 1200 (MT6893) - Sophgo SG2044 - Renesas RZ/V2N (R9A09G056) - Rockchip RK3528 - AMD ISP (new driver) Misc changes: - core: add support for Write Disable-aware SPD
Diffstat (limited to 'fs/buffer.c')
-rw-r--r--fs/buffer.c77
1 files changed, 55 insertions, 22 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index c7abb4a029dc84..7ba1807145aa8b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -176,18 +176,8 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
}
EXPORT_SYMBOL(end_buffer_write_sync);
-/*
- * Various filesystems appear to want __find_get_block to be non-blocking.
- * But it's the page lock which protects the buffers. To get around this,
- * we get exclusion from try_to_free_buffers with the blockdev mapping's
- * i_private_lock.
- *
- * Hack idea: for the blockdev mapping, i_private_lock contention
- * may be quite high. This code could TryLock the page, and if that
- * succeeds, there is no need to take i_private_lock.
- */
static struct buffer_head *
-__find_get_block_slow(struct block_device *bdev, sector_t block)
+__find_get_block_slow(struct block_device *bdev, sector_t block, bool atomic)
{
struct address_space *bd_mapping = bdev->bd_mapping;
const int blkbits = bd_mapping->host->i_blkbits;
@@ -204,10 +194,28 @@ __find_get_block_slow(struct block_device *bdev, sector_t block)
if (IS_ERR(folio))
goto out;
- spin_lock(&bd_mapping->i_private_lock);
+ /*
+ * Folio lock protects the buffers. Callers that cannot block
+ * will fallback to serializing vs try_to_free_buffers() via
+ * the i_private_lock.
+ */
+ if (atomic)
+ spin_lock(&bd_mapping->i_private_lock);
+ else
+ folio_lock(folio);
+
head = folio_buffers(folio);
if (!head)
goto out_unlock;
+ /*
+ * Upon a noref migration, the folio lock serializes here;
+ * otherwise bail.
+ */
+ if (test_bit_acquire(BH_Migrate, &head->b_state)) {
+ WARN_ON(!atomic);
+ goto out_unlock;
+ }
+
bh = head;
do {
if (!buffer_mapped(bh))
@@ -236,7 +244,10 @@ __find_get_block_slow(struct block_device *bdev, sector_t block)
1 << blkbits);
}
out_unlock:
- spin_unlock(&bd_mapping->i_private_lock);
+ if (atomic)
+ spin_unlock(&bd_mapping->i_private_lock);
+ else
+ folio_unlock(folio);
folio_put(folio);
out:
return ret;
@@ -656,7 +667,9 @@ EXPORT_SYMBOL(generic_buffers_fsync);
void write_boundary_block(struct block_device *bdev,
sector_t bblock, unsigned blocksize)
{
- struct buffer_head *bh = __find_get_block(bdev, bblock + 1, blocksize);
+ struct buffer_head *bh;
+
+ bh = __find_get_block_nonatomic(bdev, bblock + 1, blocksize);
if (bh) {
if (buffer_dirty(bh))
write_dirty_buffer(bh, 0);
@@ -1207,10 +1220,8 @@ void mark_buffer_write_io_error(struct buffer_head *bh)
/* FIXME: do we need to set this in both places? */
if (bh->b_folio && bh->b_folio->mapping)
mapping_set_error(bh->b_folio->mapping, -EIO);
- if (bh->b_assoc_map) {
+ if (bh->b_assoc_map)
mapping_set_error(bh->b_assoc_map, -EIO);
- errseq_set(&bh->b_assoc_map->host->i_sb->s_wb_err, -EIO);
- }
}
EXPORT_SYMBOL(mark_buffer_write_io_error);
@@ -1386,16 +1397,18 @@ lookup_bh_lru(struct block_device *bdev, sector_t block, unsigned size)
/*
* Perform a pagecache lookup for the matching buffer. If it's there, refresh
* it in the LRU and mark it as accessed. If it is not present then return
- * NULL
+ * NULL. Atomic context callers may also return NULL if the buffer is being
+ * migrated; similarly the page is not marked accessed either.
*/
-struct buffer_head *
-__find_get_block(struct block_device *bdev, sector_t block, unsigned size)
+static struct buffer_head *
+find_get_block_common(struct block_device *bdev, sector_t block,
+ unsigned size, bool atomic)
{
struct buffer_head *bh = lookup_bh_lru(bdev, block, size);
if (bh == NULL) {
/* __find_get_block_slow will mark the page accessed */
- bh = __find_get_block_slow(bdev, block);
+ bh = __find_get_block_slow(bdev, block, atomic);
if (bh)
bh_lru_install(bh);
} else
@@ -1403,8 +1416,23 @@ __find_get_block(struct block_device *bdev, sector_t block, unsigned size)
return bh;
}
+
+struct buffer_head *
+__find_get_block(struct block_device *bdev, sector_t block, unsigned size)
+{
+ return find_get_block_common(bdev, block, size, true);
+}
EXPORT_SYMBOL(__find_get_block);
+/* same as __find_get_block() but allows sleeping contexts */
+struct buffer_head *
+__find_get_block_nonatomic(struct block_device *bdev, sector_t block,
+ unsigned size)
+{
+ return find_get_block_common(bdev, block, size, false);
+}
+EXPORT_SYMBOL(__find_get_block_nonatomic);
+
/**
* bdev_getblk - Get a buffer_head in a block device's buffer cache.
* @bdev: The block device.
@@ -1422,7 +1450,12 @@ EXPORT_SYMBOL(__find_get_block);
struct buffer_head *bdev_getblk(struct block_device *bdev, sector_t block,
unsigned size, gfp_t gfp)
{
- struct buffer_head *bh = __find_get_block(bdev, block, size);
+ struct buffer_head *bh;
+
+ if (gfpflags_allow_blocking(gfp))
+ bh = __find_get_block_nonatomic(bdev, block, size);
+ else
+ bh = __find_get_block(bdev, block, size);
might_alloc(gfp);
if (bh)