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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /fs/ceph/io.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'fs/ceph/io.c')
-rw-r--r--fs/ceph/io.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/fs/ceph/io.c b/fs/ceph/io.c
new file mode 100644
index 000000000..2d10f49c9
--- /dev/null
+++ b/fs/ceph/io.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Trond Myklebust
+ * Copyright (c) 2019 Jeff Layton
+ *
+ * I/O and data path helper functionality.
+ *
+ * Heavily borrowed from equivalent code in fs/nfs/io.c
+ */
+
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/rwsem.h>
+#include <linux/fs.h>
+
+#include "super.h"
+#include "io.h"
+
+/* Call with exclusively locked inode->i_rwsem */
+static void ceph_block_o_direct(struct ceph_inode_info *ci, struct inode *inode)
+{
+ bool is_odirect;
+
+ lockdep_assert_held_write(&inode->i_rwsem);
+
+ spin_lock(&ci->i_ceph_lock);
+ /* ensure that bit state is consistent */
+ smp_mb__before_atomic();
+ is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT;
+ if (is_odirect) {
+ clear_bit(CEPH_I_ODIRECT_BIT, &ci->i_ceph_flags);
+ /* ensure modified bit is visible */
+ smp_mb__after_atomic();
+ }
+ spin_unlock(&ci->i_ceph_lock);
+
+ if (is_odirect)
+ inode_dio_wait(inode);
+}
+
+/**
+ * ceph_start_io_read - declare the file is being used for buffered reads
+ * @inode: file inode
+ *
+ * Declare that a buffered read operation is about to start, and ensure
+ * that we block all direct I/O.
+ * On exit, the function ensures that the CEPH_I_ODIRECT flag is unset,
+ * and holds a shared lock on inode->i_rwsem to ensure that the flag
+ * cannot be changed.
+ * In practice, this means that buffered read operations are allowed to
+ * execute in parallel, thanks to the shared lock, whereas direct I/O
+ * operations need to wait to grab an exclusive lock in order to set
+ * CEPH_I_ODIRECT.
+ * Note that buffered writes and truncates both take a write lock on
+ * inode->i_rwsem, meaning that those are serialised w.r.t. the reads.
+ */
+int ceph_start_io_read(struct inode *inode)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ bool is_odirect;
+ int err;
+
+ /* Be an optimist! */
+ err = down_read_killable(&inode->i_rwsem);
+ if (err)
+ return err;
+
+ spin_lock(&ci->i_ceph_lock);
+ /* ensure that bit state is consistent */
+ smp_mb__before_atomic();
+ is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT;
+ spin_unlock(&ci->i_ceph_lock);
+ if (!is_odirect)
+ return 0;
+ up_read(&inode->i_rwsem);
+
+ /* Slow path.... */
+ err = down_write_killable(&inode->i_rwsem);
+ if (err)
+ return err;
+
+ ceph_block_o_direct(ci, inode);
+ downgrade_write(&inode->i_rwsem);
+
+ return 0;
+}
+
+/**
+ * ceph_end_io_read - declare that the buffered read operation is done
+ * @inode: file inode
+ *
+ * Declare that a buffered read operation is done, and release the shared
+ * lock on inode->i_rwsem.
+ */
+void
+ceph_end_io_read(struct inode *inode)
+{
+ up_read(&inode->i_rwsem);
+}
+
+/**
+ * ceph_start_io_write - declare the file is being used for buffered writes
+ * @inode: file inode
+ *
+ * Declare that a buffered write operation is about to start, and ensure
+ * that we block all direct I/O.
+ */
+int ceph_start_io_write(struct inode *inode)
+{
+ int err = down_write_killable(&inode->i_rwsem);
+ if (!err)
+ ceph_block_o_direct(ceph_inode(inode), inode);
+ return err;
+}
+
+/**
+ * ceph_end_io_write - declare that the buffered write operation is done
+ * @inode: file inode
+ *
+ * Declare that a buffered write operation is done, and release the
+ * lock on inode->i_rwsem.
+ */
+void
+ceph_end_io_write(struct inode *inode)
+{
+ up_write(&inode->i_rwsem);
+}
+
+/* Call with exclusively locked inode->i_rwsem */
+static void ceph_block_buffered(struct ceph_inode_info *ci, struct inode *inode)
+{
+ bool is_odirect;
+
+ lockdep_assert_held_write(&inode->i_rwsem);
+
+ spin_lock(&ci->i_ceph_lock);
+ /* ensure that bit state is consistent */
+ smp_mb__before_atomic();
+ is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT;
+ if (!is_odirect) {
+ set_bit(CEPH_I_ODIRECT_BIT, &ci->i_ceph_flags);
+ /* ensure modified bit is visible */
+ smp_mb__after_atomic();
+ }
+ spin_unlock(&ci->i_ceph_lock);
+
+ if (!is_odirect) {
+ /* FIXME: unmap_mapping_range? */
+ filemap_write_and_wait(inode->i_mapping);
+ }
+}
+
+/**
+ * ceph_start_io_direct - declare the file is being used for direct i/o
+ * @inode: file inode
+ *
+ * Declare that a direct I/O operation is about to start, and ensure
+ * that we block all buffered I/O.
+ * On exit, the function ensures that the CEPH_I_ODIRECT flag is set,
+ * and holds a shared lock on inode->i_rwsem to ensure that the flag
+ * cannot be changed.
+ * In practice, this means that direct I/O operations are allowed to
+ * execute in parallel, thanks to the shared lock, whereas buffered I/O
+ * operations need to wait to grab an exclusive lock in order to clear
+ * CEPH_I_ODIRECT.
+ * Note that buffered writes and truncates both take a write lock on
+ * inode->i_rwsem, meaning that those are serialised w.r.t. O_DIRECT.
+ */
+int ceph_start_io_direct(struct inode *inode)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ bool is_odirect;
+ int err;
+
+ /* Be an optimist! */
+ err = down_read_killable(&inode->i_rwsem);
+ if (err)
+ return err;
+
+ spin_lock(&ci->i_ceph_lock);
+ /* ensure that bit state is consistent */
+ smp_mb__before_atomic();
+ is_odirect = READ_ONCE(ci->i_ceph_flags) & CEPH_I_ODIRECT;
+ spin_unlock(&ci->i_ceph_lock);
+ if (is_odirect)
+ return 0;
+ up_read(&inode->i_rwsem);
+
+ /* Slow path.... */
+ err = down_write_killable(&inode->i_rwsem);
+ if (err)
+ return err;
+
+ ceph_block_buffered(ci, inode);
+ downgrade_write(&inode->i_rwsem);
+
+ return 0;
+}
+
+/**
+ * ceph_end_io_direct - declare that the direct i/o operation is done
+ * @inode: file inode
+ *
+ * Declare that a direct I/O operation is done, and release the shared
+ * lock on inode->i_rwsem.
+ */
+void
+ceph_end_io_direct(struct inode *inode)
+{
+ up_read(&inode->i_rwsem);
+}