diff options
| -rw-r--r-- | fs.c | 13 |
1 files changed, 13 insertions, 0 deletions
@@ -154,6 +154,15 @@ bfree(int dev, uint b) // Many internal file system functions expect the caller to // have locked the inodes involved; this lets callers create // multi-step atomic operations. +// +// The icache.lock spin-lock defends ip->ref, ip->dev, and ip->inum. +// Since ip->ref indicates whether an icache entry is free, the +// icache.lock defends icache allocation. icache.lock also defends +// all fields of an unallocated icache entry, during allocation. +// +// An ip->lock sleep-lock defends all ip-> fields other than ref, +// dev, and inum. One must hold ip->lock in order to +// read or write that inode's ip->valid, ip->size, ip->type, &c. struct { struct spinlock lock; @@ -205,6 +214,7 @@ ialloc(uint dev, short type) } // Copy a modified in-memory inode to disk. +// Caller must hold ip->lock. void iupdate(struct inode *ip) { @@ -421,6 +431,7 @@ itrunc(struct inode *ip) } // Copy stat information from inode. +// Caller must hold ip->lock. void stati(struct inode *ip, struct stat *st) { @@ -433,6 +444,7 @@ stati(struct inode *ip, struct stat *st) //PAGEBREAK! // Read data from inode. +// Caller must hold ip->lock. int readi(struct inode *ip, char *dst, uint off, uint n) { @@ -461,6 +473,7 @@ readi(struct inode *ip, char *dst, uint off, uint n) // PAGEBREAK! // Write data to inode. +// Caller must hold ip->lock. int writei(struct inode *ip, char *src, uint off, uint n) { |