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| author | Arnd Bergmann <arnd@arndb.de> | 2010-09-12 19:05:56 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-04 21:10:45 +0200 |
| commit | 4f819a7899b06afcd7623ab9d00fd81503ad3e24 (patch) | |
| tree | 4506a992e9207f6374803e89d9a0e9b9a9b33ddb /fs/isofs/namei.c | |
| parent | 3768744cfea7b995dce27f02341161fbfdfee80c (diff) | |
| download | linux-4f819a7899b06afcd7623ab9d00fd81503ad3e24.tar.gz | |
BKL: Remove BKL from isofs
As in other file systems, we can replace the big kernel lock with a private mutex in isofs. This means we can now access multiple file systems concurrently, but it also means that we serialize readdir and lookup across sleeping operations which previously released the big kernel lock. This should not matter though, as these operations are in practice serialized through the hardware access. The isofs_get_blocks functions now does not take any lock any more, it used to recursively get the BKL. After looking at the code for hours, I convinced myself that it was never needed here anyway, because it only reads constant fields of the inode and writes to a buffer head array that is at this time only visible to the caller. The get_sb and fill_super operations do not need the locking at all because they operate on a file system that is either about to be created or to be destroyed but in either case is not visible to other threads. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'fs/isofs/namei.c')
| -rw-r--r-- | fs/isofs/namei.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c index ab438beb867c..0d23abfd4280 100644 --- a/fs/isofs/namei.c +++ b/fs/isofs/namei.c @@ -6,7 +6,6 @@ * (C) 1991 Linus Torvalds - minix filesystem */ -#include <linux/smp_lock.h> #include <linux/gfp.h> #include "isofs.h" @@ -168,6 +167,7 @@ struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nam int found; unsigned long uninitialized_var(block); unsigned long uninitialized_var(offset); + struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb); struct inode *inode; struct page *page; @@ -177,7 +177,7 @@ struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nam if (!page) return ERR_PTR(-ENOMEM); - lock_kernel(); + mutex_lock(&sbi->s_mutex); found = isofs_find_entry(dir, dentry, &block, &offset, page_address(page), @@ -188,10 +188,10 @@ struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nam if (found) { inode = isofs_iget(dir->i_sb, block, offset); if (IS_ERR(inode)) { - unlock_kernel(); + mutex_unlock(&sbi->s_mutex); return ERR_CAST(inode); } } - unlock_kernel(); + mutex_unlock(&sbi->s_mutex); return d_splice_alias(inode, dentry); } |