/* * Copyright (c) 2016 Trond Myklebust * * I/O and data path helper functionality. */ #include #include #include #include #include #include #include "internal.h" /* Call with exclusively locked inode->i_rwsem */ static void nfs_block_o_direct(struct nfs_inode *nfsi, struct inode *inode) { if (test_bit(NFS_INO_ODIRECT, &nfsi->flags)) { clear_bit(NFS_INO_ODIRECT, &nfsi->flags); inode_dio_wait(inode); } } /** * nfs_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 NFS_INO_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 * NFS_INO_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. */ void nfs_start_io_read(struct inode *inode) { struct nfs_inode *nfsi = NFS_I(inode); /* Be an optimist! */ down_read(&inode->i_rwsem); if (test_bit(NFS_INO_ODIRECT, &nfsi->flags) == 0) return; up_read(&inode->i_rwsem); /* Slow path.... */ down_write(&inode->i_rwsem); nfs_block_o_direct(nfsi, inode); downgrade_write(&inode->i_rwsem); } /** * nfs_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 nfs_end_io_read(struct inode *inode) { up_read(&inode->i_rwsem); } /** * nfs_start_io_write - declare the file is being used for buffered writes * @inode - file inode * * Declare that a buffered read operation is about to start, and ensure * that we block all direct I/O. */ void nfs_start_io_write(struct inode *inode) { down_write(&inode->i_rwsem); nfs_block_o_direct(NFS_I(inode), inode); } /** * nfs_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 nfs_end_io_write(struct inode *inode) { up_write(&inode->i_rwsem); } /* Call with exclusively locked inode->i_rwsem */ static void nfs_block_buffered(struct nfs_inode *nfsi, struct inode *inode) { if (!test_bit(NFS_INO_ODIRECT, &nfsi->flags)) { set_bit(NFS_INO_ODIRECT, &nfsi->flags); nfs_wb_all(inode); } } /** * nfs_end_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 NFS_INO_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 * NFS_INO_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. */ void nfs_start_io_direct(struct inode *inode) { struct nfs_inode *nfsi = NFS_I(inode); /* Be an optimist! */ down_read(&inode->i_rwsem); if (test_bit(NFS_INO_ODIRECT, &nfsi->flags) != 0) return; up_read(&inode->i_rwsem); /* Slow path.... */ down_write(&inode->i_rwsem); nfs_block_buffered(nfsi, inode); downgrade_write(&inode->i_rwsem); } /** * nfs_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 nfs_end_io_direct(struct inode *inode) { up_read(&inode->i_rwsem); } it();'>mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-06 14:16:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-06 14:16:23 -0800
commit396bf4cd835e62d70fad4a03a8963e61f19021f2 (patch)
tree79ac8f33554260fea1a8d43e6f8c4c5460115f45 /include/drm/drm_connector.h
parentd5adbfcd5f7bcc6fa58a41c5c5ada0e5c826ce2c (diff)
parent7c2cf1c4615cc2f576d0604406cdf0065f00b83b (diff)
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu: - use-after-free in algif_aead - modular aesni regression when pcbc is modular but absent - bug causing IO page faults in ccp - double list add in ccp - NULL pointer dereference in qat (two patches) - panic in chcr - NULL pointer dereference in chcr - out-of-bound access in chcr * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: chcr - Fix key length for RFC4106 crypto: algif_aead - Fix kernel panic on list_del crypto: aesni - Fix failure when pcbc module is absent crypto: ccp - Fix double add when creating new DMA command crypto: ccp - Fix DMA operations when IOMMU is enabled crypto: chcr - Check device is allocated before use crypto: chcr - Fix panic on dma_unmap_sg crypto: qat - zero esram only for DH85x devices crypto: qat - fix bar discovery for c62x
Diffstat (limited to 'include/drm/drm_connector.h')